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If there's one light on your car's 
instrument panel you should never, ever ignore,

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it's this one:

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the oil pressure warning light.

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It usually looks like a little oiling can.

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And if that light comes on while you're driving,

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that means you should pull over and 
shut off the engine as soon as you can possibly do so safely

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and then call a tow truck.

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And I'm not kidding.

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If that light comes on,

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your engine may be mere minutes away from self-destruction.

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And so continuing to drive is a very risky choice to make.

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Now, if you're wondering why exactly the engine 
could destroy itself when that light comes on,

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that's the point of this video.

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Today we're going to explore the mechanical basics of the internal combustion engine,

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with a particular focus on its lubrication system 
and why it's required to keep the engine alive.

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There's a lot of stuff going on inside one of these contraptions, 
and by the time we're done here

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there's a good chance you'll think it's a miracle we've managed to make these things as reliable as they usually are.

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Now, if you're a gearhead or even just gearhead-adjacent,

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there's probably not much you're going to learn here.

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But if you don't really know that much 
about engines and how they work,

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and really how they keep themselves working,

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well I think you'll find this video to be quite informative.

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Before we really dive in, though,

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there's something you should know about the rest of the lights on your car's instrument cluster.

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And that's something is the rest of them!

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Because they all mean very important things
and are designed to help you.

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They're even color coded to convey their urgency and meaning.

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Red lights are bad and need your attention now

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because they indicate an unsafe condition 
where something is majorly wrong.

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Yellow lights are warnings which can vary in severity

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but probably don't need your immediate attention.

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And other colors are usually reserved for simple information,

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like the blue light that warns you your high beams are on

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so please shut them off unless you're in the middle of the country — that's not for use with other cars around!

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Or the white or green status 
indicators for the cruise control system.

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If you want to know just what exactly all those lights mean,

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your car will have an owner's manual somewhere

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and there's going to be a handy little section which explains each and every one of them and why they might light up.

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I'd highly encourage looking at that section of the manual

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and committing those details to memory.

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But anyway, this is a video about the engine and how it works.

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So let's dig into it.

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First, though, if you'll indulge me,

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here's a brief overview of how electric cars work:

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[two toots of the drill]

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But bigger.

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And now let's take a look at this Renault-Nissan MR-18DE,

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the engine which powers the venerable Nissan Cube.

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Let me just, uh, take it apart real quick.

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Okay,

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this is the engine block.

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It's really nothing more than an intricately cast 
and machined hunk of metal,

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but it's the heart of the engine and contains the cylinders.

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In this case, there are four of them,

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and they're all arranged in a straight line,

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which makes this an inline four cylinder engine.

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Probably the most common type of engine out there in cars.

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Not all four cylinder engines are alike, of course;

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these cylinders come in many different sizes, 
so some are more powerful than others,

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and they're not always arranged in a line.

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We'll talk more about that later, though.

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Oh also sometimes there aren't cylinders at all!

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But that's mainly a Mazda thing they only sometimes do

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because rotary engines are equal parts cool and terrible.

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But they're committed to them!

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Sometimes - for special occasions.

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Anyway, the cylinders are each a combustion chamber.

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The idea is to fill these cylinders with a mixture of air and fuel,

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and then ignite that mixture so it...

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expands very rapidly.

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I would say that mixture explodes,

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but it's not technically an explosion.

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What's really happening is that the carbon dioxide

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and water vapor that are produced in the combustion process

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have a much larger volume 
than the fuel and air did before it ignited,

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and that rapid expansion of hot gases 
inside the combustion chamber

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can be harnessed and turned into mechanical work.

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And to do that we use pistons.

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Each cylinder gets a piston just like this inserted from the bottom,

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and these pistons are able to 
slide up and down inside the cylinders.

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During a combustion event, as the mixture of hot gases inside the cylinder rapidly expands

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these pistons are forced downward into the engine block.

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And that's how we convert the chemical 
energy in the fuel into mechanical energy.

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Now, the goal of this engine is to spin the wheels of a car.

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So ultimately the engine produces rotational movement.

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And since the pistons move up and down inside the cylinders,

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we're going to need a mechanism to translate 
their up and down motion into a spinning motion.

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If you noticed the weird stick thing 
with a ring on the end that each piston has,

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well, this is the connecting rod 
and it's there to connect the pistons

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to this thing.

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This is the crankshaft, and it is the thing that spins.

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The tachometer, the gauge which tells you engine RPM,

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is telling you how quickly this literal thing 
is spinning inside the engine block.

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Now we're going to look at this closely 
in a moment to see how the pistons make it spin.

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But first I want to point out that the crankshaft 
sticks out from the block on both sides.

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That is how we actually make this spinning crankshaft

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do useful things for us.

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Bolted to one side of it

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is this large rusty wheel with teeth on its edges.

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This is what's known as a flexplate.

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The teeth on its circumference are there 
for the electric starter motor to engage with,

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and turn the crankshaft 
inside the engine in order to start it from a stop.

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But the rest of this connects the engine to the transmission

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so that once the engine is running

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the spinning crankshaft can spin the wheels of the car.

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Technical note: if you were expecting me to call this a flywheel,

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well, this is not a flywheel.

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It's a flexplate.

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What's the difference?

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Well, flywheels are used with manual transmissions,

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while flexplates are used with automatic transmissions.

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In a car with an automatic,
which is what this engine was taken from,

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the flexplate gets fastened 
to the transmission's torque converter,

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and the engine and transmission 
are permanently coupled together.

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But flywheels are completely different.

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They're used with manual transmissions

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and are not really fastened to the transmission at all,

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since in a stick shift the engine and transmission 
are mated with a clutch under the driver's control.

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The clutch sort of presses up against the flywheel

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when engaged to connect the transmission to the engine,

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and it moves away from the flywheel when disengaged to separate them.

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And because of this, flywheels have a smooth surface

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on the outer side which the clutch pushes against.

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It's also quite a lot thicker and heavier than a flexplate

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to give the crankshaft more rotational momentum:

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helpful when getting the car moving from a stop.

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This Nissan Cube has a manual transmission,

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so its engine has a flywheel 
attached to the crankshaft and not a flexplate,

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but everything else is identical.

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Now, while moving the car is the main thing the spinning crankshaft has to do,

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it also has to do things like generate electricity to keep the car's battery charged.

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And that needs to happen whether the wheels are moving or not.

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Which is why the other end of the crankshaft 
also sticks out from the engine block.

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But on this side, all we have attached to it is the small pulley.

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This is the crank pulley

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and it provides power for engine accessories such as the alternator,

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air conditioning compressor and water pump via a drive belt.

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The pulley simply bolts on to the end of the crankshaft here...

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with this large bolt.

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Oh, and like in many engines,

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that pulley has some rubber like material in there

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to allow it to function as a harmonic balancer.

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But that's not important right now.

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What is important right now

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is how the uppy downy pistons actually make 
the spinny spinny crankshaft spin in the first place.

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To explain, I want you to focus on these very shiny

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and perfectly circular surfaces you can find on the crankshaft.

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These are bearings,

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just plain bearings.

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which is a dad joke because 
they are literally called plain bearings.

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[voiceover]
Oooookay editor me popping in

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with some notes on terminology.

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I made the mistake when writing this script

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of letting a technical definition supersede

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the common language most people use.

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These are indeed plain bearings,

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but they belong to a subset of 
plain bearing known as journal bearings.

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And the circular, shiny things we're looking at on the crankshaft

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are usually referred to as the journals.

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But here's the thing.

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Journal is simply another word for shaft.

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All these things are is a polished, circular shaft

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which spins inside of a stationary circle,

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which wraps around and holds on to the shaft.

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Once put together, it's really just two concentric circles

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where one spins and the other doesn't.

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And both the spinning journal and its stationary

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holder are a bearing surface,

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which is what I wanted to highlight in this video.

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The interface between those two bearing surfaces

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is what really matters to the point here.

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And from either one's individual perspective,

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the other part is what's spinning.

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And so that's why I ultimately chose to refer to these as bearings.

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But I understand a lot of people will be very annoyed by that choice.

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And so... sorry about that.

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They consist of that smooth,

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shiny part in the center of the crankshaft

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and a thin bushing which surrounds it.

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You can see half of the bushings here in the block.

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[voiceover]
Oh, hi. Me again.

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See, this right here explains the problem.

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This is literally the bearing.

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This is the bearing surface.

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But technically it is a bushing.

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However, when people rebuild engines,

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they're going to refer to these things

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as the bearing because it's the bearing surface.

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And hopefully that helps explain why I had such decision

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paralysis around the terminology here.

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Five of the bearings are all arranged in a straight line.

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These are the main bearings

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which hold the crankshaft in the block and keep it centered,

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but the remaining four are wildly offset from the rest.

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These eccentric bearings are what the pistons attach to.

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The big round part at the bottom of the connecting rod

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can be split in half by loosening these fasteners.

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And then you can attach the piston and its bushings

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to its respective bearing.

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Now, I want to point out as I very loosely attach this,

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that the mating surfaces here are both metal.

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This is literally metal on metal contact,

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and these components slide against each other as they spin around,

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which feels problematic, doesn't it?

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Keep that in mind as we continue.

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If you're wondering why the 
crankshaft has these weird lobe things,

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well, remember, this is the thing that spins.

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And since the bearings that the pistons 
attach to are wildly offset from the center,

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you need counterweights to keep it balanced.

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And that's what these are.

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This is roughly how fast the 
crankshaft spins when the engine is at idle!

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And at redline, it can be spinning ten times as fast.

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So you really want this thing

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as perfectly balanced as you can possibly get it

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to reduce vibration which could tear the engine apart.

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And you can even see marks 
where small amounts of material were drilled

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out of the counterweights after casting to make fine adjustments to balance.

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But anyway, back to the pistons.

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Once assembled, the pistons function

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very much like your feet when pedaling a bicycle.

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In fact, if you look at the crankshaft closely,

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you'll see that on each end of it

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is basically the exact same 
mechanism as the crank arm of a bike.

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And here's what it looks like with 
all the pistons attached and the crankshaft turning.

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There are several things wrong with this demonstration.

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For instance, this is upside down.

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But you'll notice that as the crankshaft rotates,

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the four pistons move up and down into pairs.

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When the outer two are at the bottom,

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the inner two are at the top and Nissan Versa,

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and they go round and round like a very strange Ferris wheel.

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I mean, there is a lot of iron in there.

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and here's what that looks like with the pistons and crankshaft inside the block

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and the starter motor turning the crankshaft.

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The block constrains the lateral movement of the pistons

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which means the piston needs to be able to pivot back

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and forth with respect to its connecting rod

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as it flies around the crankshaft below.

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That's why the connecting rod

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is attached to the piston with what's called a wrist pin 
(or gudgeon pin if you're British).

241
00:13:23,569 --> 00:13:28,474
That allows the top of the piston to sort of wiggle back and forth with respect to its connecting rod.

242
00:13:28,974 --> 00:13:33,546
And that's how the piston can stay on 
a perfectly vertical track inside the block,

243
00:13:33,846 --> 00:13:37,116
while its connecting rod is flailing all around below.

244
00:13:37,983 --> 00:13:39,118
Here's a fun fact!

245
00:13:39,118 --> 00:13:40,519
While editing this video,

246
00:13:40,553 --> 00:13:44,490
I discovered that I accidentally deleted this section from the script.

247
00:13:44,490 --> 00:13:45,925
So here's me putting it back!

248
00:13:46,592 --> 00:13:49,228
When we are talking about an engine's size,

249
00:13:49,528 --> 00:13:53,966
we're not actually talking about 
how large the cylinders in the block are.

250
00:13:54,733 --> 00:13:56,735
At least not entirely.

251
00:13:57,503 --> 00:14:00,773
We measure an engine's size by its displacement,

252
00:14:00,773 --> 00:14:05,277
and that is defined by how much volume the pistons displace

253
00:14:05,477 --> 00:14:08,180
as they move up and down inside the cylinders.

254
00:14:08,981 --> 00:14:11,517
The pistons can only move down so far,

255
00:14:11,717 --> 00:14:13,819
which only opens up so much space.

256
00:14:14,119 --> 00:14:16,722
And in this engine, each piston moves

257
00:14:16,722 --> 00:14:20,025
through a volume of 450cm³.

258
00:14:20,759 --> 00:14:23,596
There are four of them, of course, and added together,

259
00:14:23,596 --> 00:14:26,599
that means the pistons displace a total volume

260
00:14:26,799 --> 00:14:31,670
of 1800cm³, or 1.8 liters.

261
00:14:31,937 --> 00:14:34,974
And that is why this is a 1.8l engine.

262
00:14:35,708 --> 00:14:39,144
However, we could increase this engine's displacement

263
00:14:39,144 --> 00:14:41,580
without making the cylinders any bigger at all.

264
00:14:42,314 --> 00:14:46,218
All we'd need to do is increase the stroke of the pistons

265
00:14:46,218 --> 00:14:51,891
so that they travel farther down before they start 
heading back up, and boom, more displacement!

266
00:14:53,192 --> 00:14:57,529
But that's much easier said than done, because to actually make that happen,

267
00:14:57,730 --> 00:15:02,001
we'd need an entirely different and much larger crankshaft,

268
00:15:02,401 --> 00:15:04,403
which will require redesigning the block.

269
00:15:05,004 --> 00:15:11,977
And the power delivery characteristics of a piston engine can vary dramatically when the pistons have a longer stroke,

270
00:15:12,211 --> 00:15:15,614
so it might not be desirable for all applications.

271
00:15:16,548 --> 00:15:18,250
This is all very complicated,

272
00:15:18,384 --> 00:15:22,021
but an engine's displacement presents a hard limit

273
00:15:22,021 --> 00:15:24,523
to how much power it can theoretically produce,

274
00:15:24,790 --> 00:15:26,759
and this is why, purportedly,

275
00:15:27,092 --> 00:15:29,361
there is no replacement for displacement.

276
00:15:30,930 --> 00:15:35,100
Then again, my daily driver has an engine displacement of null,

277
00:15:35,100 --> 00:15:39,038
and yet it can still do 0 to 60 in well under five seconds.

278
00:15:39,405 --> 00:15:41,473
So I'm not sure how true that is these days.

279
00:15:41,473 --> 00:15:42,675
But anyway, let's move on.

280
00:15:43,108 --> 00:15:47,880
And at this point, we've looked at nearly everything 
which lives inside the engine block.

281
00:15:48,781 --> 00:15:51,984
But now you might have noticed a bit of a problem.

282
00:15:52,851 --> 00:15:55,354
I said that the cylinders are combustion chambers

283
00:15:55,521 --> 00:15:58,357
and expanding gases pushed the pistons down.

284
00:15:59,158 --> 00:16:00,993
But, uh, right now

285
00:16:00,993 --> 00:16:03,228
those gases don't have anything to push against.

286
00:16:03,629 --> 00:16:05,864
This is just a weird series of cups

287
00:16:05,864 --> 00:16:08,300
where the bottom can move up and down for some reason.

288
00:16:09,268 --> 00:16:12,304
To actually turn all these into combustion chambers,

289
00:16:12,538 --> 00:16:13,739
we need to seal it up.

290
00:16:14,006 --> 00:16:16,008
And that's done with the cylinder head.

291
00:16:16,775 --> 00:16:18,877
But also the piston rings.

292
00:16:19,478 --> 00:16:22,181
Before we even talk about sealing the top of the chamber,

293
00:16:22,381 --> 00:16:26,285
we also need a seal between the pistons themselves and the walls of the cylinders.

294
00:16:27,119 --> 00:16:29,288
The pistons are actually slightly smaller

295
00:16:29,288 --> 00:16:31,757
than the cylinders and can flop around in there a little bit.

296
00:16:32,024 --> 00:16:35,060
So each one has not one, not two,

297
00:16:35,494 --> 00:16:40,866
but two piston rings and a third oil control ring, 
which is a kind of piston ring,

298
00:16:40,866 --> 00:16:42,067
but it doesn't have the same job.

299
00:16:42,868 --> 00:16:49,908
The two piston rings near the top, known as compression rings, are simply metal rings with a bit of spring tension in them

300
00:16:50,109 --> 00:16:54,980
which causes them to expand and fill 
the gap between the piston and the cylinder walls.

301
00:16:56,048 --> 00:16:59,418
There are two of them because
in order to put the ring on the piston,

302
00:16:59,885 --> 00:17:04,123
it needs a gap, and that gap means the seal isn't so good.

303
00:17:04,123 --> 00:17:06,925
So, well, we just throw a second one on there,

304
00:17:06,925 --> 00:17:09,962
and ideally you'll position the gaps on opposite side -

305
00:17:10,295 --> 00:17:11,290
Well, that one broke!

306
00:17:11,290 --> 00:17:14,795
[through laughter]
on opposite sides of the piston when putting the thing together.

307
00:17:15,034 --> 00:17:18,971
So with the pistons now 
sufficiently sealed against the cylinders,

308
00:17:19,371 --> 00:17:23,375
we have to seal the top of this thing 
so that we have an actual combustion chamber.

309
00:17:24,176 --> 00:17:26,745
And that's what this guy is for.

310
00:17:27,446 --> 00:17:29,181
This is the cylinder head

311
00:17:29,481 --> 00:17:33,845
and it gets bolted to the top of the block and, with the help of the head gasket,

312
00:17:33,845 --> 00:17:38,157
actually seals the cylinders up 
so they can become combustion chambers.

313
00:17:38,824 --> 00:17:41,326
But this does far more than just that.

314
00:17:41,760 --> 00:17:45,264
This is also what allows fresh air and fuel into the cylinders,

315
00:17:45,397 --> 00:17:47,399
what expels exhaust from the cylinders,

316
00:17:47,800 --> 00:17:49,968
and what ignites the air/fuel mixture.

317
00:17:52,638 --> 00:17:55,007
Well, the spark plug is what does that for each cylinder.

318
00:17:55,007 --> 00:17:56,608
But the spark plugs live in the cylinder head.

319
00:17:56,975 --> 00:17:58,911
You can, see 'em poking out just there.

320
00:17:59,611 --> 00:18:04,750
To actually let air and fuel into, 
as well as exhaust out of, the combustion chambers,

321
00:18:05,050 --> 00:18:07,286
the cylinder head contains valves.

322
00:18:07,886 --> 00:18:12,958
Like most modern engines there are four valves per cylinder, 
two each for intake and exhaust.

323
00:18:13,759 --> 00:18:15,694
You really only need one of each,

324
00:18:15,961 --> 00:18:18,764
but geometry makes it so you can have more total area

325
00:18:18,764 --> 00:18:22,000
if you have two smaller valves rather than one big one,

326
00:18:22,401 --> 00:18:24,503
and that allows the engine to breathe more easily.

327
00:18:25,370 --> 00:18:28,173
From this side, the valves look like little circles,

328
00:18:28,173 --> 00:18:31,577
but what they actually look like is golf tees.

329
00:18:32,111 --> 00:18:33,245
And I'm totally serious.

330
00:18:33,245 --> 00:18:35,481
They're basically just large golf tees.

331
00:18:36,215 --> 00:18:38,750
I'd remove one to show you, but you see,

332
00:18:38,750 --> 00:18:41,286
they're held shut with extremely powerful springs

333
00:18:41,286 --> 00:18:43,655
and I do not have the guts to remove them for you.

334
00:18:45,190 --> 00:18:46,391
So I bought these ones!

335
00:18:47,059 --> 00:18:49,795
All that each of these little valves is really doing

336
00:18:50,295 --> 00:18:52,498
is plugging a hole in the cylinder head.

337
00:18:53,198 --> 00:18:56,702
On the sides of the cylinder head are the intake and exhaust ports.

338
00:18:57,169 --> 00:19:01,039
These are where air and fuel goes into the engine on one side

339
00:19:01,206 --> 00:19:03,108
and exhaust comes out of it on the other.

340
00:19:03,976 --> 00:19:09,248
Look into those ports and you can see the backsides of the valves and the holes that they're plugging.

341
00:19:10,282 --> 00:19:13,218
To keep that hole plugged up and the combustion chamber sealed,

342
00:19:13,519 --> 00:19:16,255
a spring being held by this retaining mechanism

343
00:19:16,455 --> 00:19:21,326
is constantly pulling up on the 
valve stem and keeping it firmly in its seat.

344
00:19:22,094 --> 00:19:26,064
But if something pushes down hard enough to overcome the force of the spring,

345
00:19:26,398 --> 00:19:29,001
the valves will poke out from where they sit

346
00:19:29,268 --> 00:19:31,737
and suddenly the hole isn't plugged any longer.

347
00:19:32,237 --> 00:19:36,842
There is now a pathway for air to make its way through this port and into the cylinder.

348
00:19:37,843 --> 00:19:42,047
We now have all the ingredients 
to make a series of combustion chambers

349
00:19:42,247 --> 00:19:45,851
that we can move gases into and out of under our control.

350
00:19:46,251 --> 00:19:49,955
But what actually opens and closes the valves?

351
00:19:51,590 --> 00:19:53,559
Well, these things,

352
00:19:53,792 --> 00:19:55,794
but, more on them in a moment.

353
00:19:56,028 --> 00:19:59,331
Now, we need to discuss the four stroke engine cycle.

354
00:20:00,132 --> 00:20:04,198
Virtually every engine out there 
which isn't a very big diesel engine

355
00:20:04,198 --> 00:20:05,904
or a very small weed whacker engine,

356
00:20:05,904 --> 00:20:09,675
or in a very old car is a four stroke engine,

357
00:20:09,875 --> 00:20:12,544
which means that when looking at a single cylinder,

358
00:20:12,744 --> 00:20:15,280
the piston actually travels up and down

359
00:20:15,280 --> 00:20:17,916
two complete times per combustion event.

360
00:20:18,684 --> 00:20:21,353
First, it travels down during the intake stroke,

361
00:20:21,353 --> 00:20:26,291
where the intake valve is open and fresh air 
and fuel is brought into the cylinder.

362
00:20:27,092 --> 00:20:30,696
Then the valves will close and the piston travels back up

363
00:20:30,696 --> 00:20:35,634
during the compression stroke, which squeezes 
that air and fuel into a tiny little space.

364
00:20:36,368 --> 00:20:37,703
When the piston is at the top,

365
00:20:37,803 --> 00:20:39,137
the spark plug fires

366
00:20:39,137 --> 00:20:43,642
which ignites that mixture and forces the piston down during the power stroke,

367
00:20:43,642 --> 00:20:46,311
which is the only stroke that actually produces motive power.

368
00:20:47,212 --> 00:20:49,314
And finally, the piston moves back up again

369
00:20:49,314 --> 00:20:53,018
with the exhaust valve open during the exhaust stroke,

370
00:20:53,218 --> 00:20:56,488
where the piston will push the exhaust gases out of the cylinder.

371
00:20:57,356 --> 00:20:58,523
And then that repeats.

372
00:20:58,523 --> 00:21:01,960
That's intake, compression, power, and exhaust.

373
00:21:02,427 --> 00:21:03,996
And for a helpful way to remember that,

374
00:21:03,996 --> 00:21:06,565
which I'm sure many of you out there really want me to say...

375
00:21:07,566 --> 00:21:09,434
suck, squeeze, bang, blow.

376
00:21:10,302 --> 00:21:12,971
To make that sequence actually happen though,

377
00:21:12,971 --> 00:21:18,076
the valves need to open and close in time 
with the movement of the pistons in the block.

378
00:21:18,844 --> 00:21:23,015
And to make that happen, we use rotating camshafts like this.

379
00:21:24,116 --> 00:21:28,787
These fellas are held captive with 
this bracket and spin above the valves.

380
00:21:29,521 --> 00:21:35,494
When the pointy bit on each one of these cams, 
known as the lobe, lines up with the top of the valve,

381
00:21:35,661 --> 00:21:39,298
it will press down on its respective valve and open it.

382
00:21:40,098 --> 00:21:41,300
Here's what that looks like.

383
00:21:42,034 --> 00:21:46,071
I want to point out yet again that this is metal on metal contact,

384
00:21:46,438 --> 00:21:49,474
but you may notice in this footage that some kind of dark

385
00:21:49,474 --> 00:21:52,411
liquid appears to be oozing out of various places

386
00:21:52,644 --> 00:21:54,446
and getting all over the cams.

387
00:21:55,280 --> 00:21:56,481
That's engine oil.

388
00:21:57,282 --> 00:21:58,800
Where is it coming from?

389
00:21:59,418 --> 00:22:00,252
The oil pump.

390
00:22:00,252 --> 00:22:01,620
But hold on, we're not there yet.

391
00:22:02,187 --> 00:22:05,957
First, I want to point out that the sequence 
in which the valves are opened

392
00:22:06,191 --> 00:22:09,227
is programed by the physical shape of these things,

393
00:22:09,461 --> 00:22:12,864
and that, along with the crankshaft design, dictates

394
00:22:12,864 --> 00:22:14,499
the engine's firing order.

395
00:22:15,534 --> 00:22:18,570
This engine doesn't fire the cylinders in sequence.

396
00:22:18,704 --> 00:22:23,859
In fact, it skips around a bit with a firing order of 1 - 3 - 4 - 2

397
00:22:24,576 --> 00:22:27,379
And if I slowly rotate the camshaft,

398
00:22:27,646 --> 00:22:31,416
you'll see that the lobes stick out in that same order

399
00:22:31,416 --> 00:22:34,653
because they have to open the valves in that order.

400
00:22:35,987 --> 00:22:37,856
This engine could have been designed

401
00:22:37,856 --> 00:22:40,492
with a simple 1 - 2 - 3 - 4 firing order,

402
00:22:40,759 --> 00:22:43,328
but that would require a different crankshaft

403
00:22:43,328 --> 00:22:45,897
where pistons one and three are at the top,

404
00:22:46,098 --> 00:22:48,166
while two and four are at the bottom.

405
00:22:48,700 --> 00:22:51,169
And when you do that with an inline four cylinder,

406
00:22:51,670 --> 00:22:55,140
it tends to be even more of a vibrating mess than it already is.

407
00:22:55,140 --> 00:22:57,275
Which is why the pistons are paired like this

408
00:22:57,576 --> 00:22:59,878
and the firing order skips around a bit.

409
00:23:00,412 --> 00:23:01,713
It's just a better balance.

410
00:23:02,547 --> 00:23:05,183
But now we have a bit of a timing problem.

411
00:23:05,984 --> 00:23:09,888
We need to make absolutely sure that those valves are opening

412
00:23:09,888 --> 00:23:14,626
when they should be in relation 
to the pistons moving inside the engine block.

413
00:23:15,694 --> 00:23:21,066
One way to do that would be to mechanically interlock 
the camshafts with the crankshaft,

414
00:23:21,166 --> 00:23:23,869
which is exactly what this and any engine does,

415
00:23:24,302 --> 00:23:27,806
but it's a little more complicated than you might imagine at first.

416
00:23:28,006 --> 00:23:30,575
Recall this is a four stroke engine,

417
00:23:30,909 --> 00:23:35,814
which means the pistons travel up and down twice for every time a valve opens.

418
00:23:36,748 --> 00:23:41,720
But since the camshafts only make one rotation to open their valve,

419
00:23:42,487 --> 00:23:49,394
that means we need the camshafts to be spinning 
at exactly half the rate of the crankshaft.

420
00:23:50,061 --> 00:23:55,967
We need to do that so the crankshaft makes two rotations for every one rotation of the camshaft.

421
00:23:56,868 --> 00:24:00,439
Luckily, that's easy to do with our old friend gears.

422
00:24:01,139 --> 00:24:02,808
You may have noticed a couple of gears

423
00:24:02,808 --> 00:24:05,444
on the end of the crankshaft away from the flex plate.

424
00:24:06,111 --> 00:24:10,649
This smaller gear will drive 
the camshafts with the help of a chain.

425
00:24:11,650 --> 00:24:13,785
That's this guy, the timing chain,

426
00:24:14,119 --> 00:24:17,155
and it lives underneath this cover on the side of the engine.

427
00:24:17,889 --> 00:24:21,793
Its job is to transmit motion from the crankshaft at the bottom

428
00:24:22,194 --> 00:24:24,729
all the way up to the camshafts at the top.

429
00:24:25,964 --> 00:24:29,534
Now the chain is going to keep 
them mechanically locked together,

430
00:24:29,868 --> 00:24:35,073
but importantly, the crankshaft's 
gear has exactly half as many teeth

431
00:24:35,273 --> 00:24:37,509
as the gears which drive the camshafts.

432
00:24:38,109 --> 00:24:40,479
There are 23 teeth on the crankshaft gear

433
00:24:40,679 --> 00:24:43,482
and 46 on both of these camshaft gears,

434
00:24:44,049 --> 00:24:49,087
and that ratio will ensure it always takes 
exactly two rotations of the crankshaft

435
00:24:49,354 --> 00:24:52,390
for the camshaft to make a single rotation.

436
00:24:52,991 --> 00:24:54,793
And so long as this chain doesn't break,

437
00:24:55,093 --> 00:24:57,562
they will remain perfectly locked together

438
00:24:57,562 --> 00:25:00,565
such that the valves always open at the same time

439
00:25:00,765 --> 00:25:03,435
in relation to the pistons inside the engine block.

440
00:25:04,503 --> 00:25:08,240
Of course, we can actually 
fiddle with that while the engine is running,

441
00:25:08,240 --> 00:25:10,408
and that's why this gear is so thick.

442
00:25:10,408 --> 00:25:12,444
But we are not getting into that today!

443
00:25:13,245 --> 00:25:17,282
At this point, I've covered all the 
mechanical basics of this engine.

444
00:25:17,649 --> 00:25:20,252
And while this is a very common design,

445
00:25:20,552 --> 00:25:22,320
it's by no means universal.

446
00:25:22,954 --> 00:25:25,657
For one thing, lots of engines have more than

447
00:25:25,657 --> 00:25:27,792
or even less than four cylinders.

448
00:25:28,260 --> 00:25:33,298
Three cylinder engines have snuck their way into lots of cars 
these days, and many people haven't seemed to notice.

449
00:25:33,765 --> 00:25:36,968
And of course, there's all those V6es and V8s

450
00:25:37,736 --> 00:25:39,571
V engines are interesting

451
00:25:39,571 --> 00:25:46,611
because they add a second bank of cylinders, 
but both banks of pistons share a single crankshaft.

452
00:25:47,412 --> 00:25:51,516
This makes them only marginally larger 
than their inline counterparts,

453
00:25:51,683 --> 00:25:55,520
while doubling the number of cylinders,
and thus the power it can produce.

454
00:25:56,421 --> 00:26:00,425
But more cylinders means 
a thirstier engine which costs more to operate,

455
00:26:00,792 --> 00:26:03,361
which is why the old four banger is so dang common.

456
00:26:04,563 --> 00:26:05,764
It's good enough.

457
00:26:06,364 --> 00:26:10,068
but even within inline fours, there's a ton of variation.

458
00:26:10,769 --> 00:26:15,574
This engine has separate camshafts 
for the intake valves and the exhaust valves,

459
00:26:15,874 --> 00:26:18,810
and where these live is above the cylinder head.

460
00:26:19,144 --> 00:26:22,347
And that makes this a dual overhead cam engine.

461
00:26:23,148 --> 00:26:25,917
If you've ever seen DOHC on an engine cover

462
00:26:25,917 --> 00:26:28,386
or like on the side of an old car as a badge,

463
00:26:28,954 --> 00:26:32,023
that is literally referring to these two cams

464
00:26:32,023 --> 00:26:34,893
and where they are in relation to the rest of the engine.

465
00:26:35,894 --> 00:26:38,797
Some engines only use one camshaft,

466
00:26:39,064 --> 00:26:44,369
but it will have more lobes on it, so it can actuate 
both the intake and the exhaust valves.

467
00:26:44,636 --> 00:26:47,405
And that would be a single overhead cam engine,

468
00:26:47,439 --> 00:26:48,640
SOHC.

469
00:26:49,174 --> 00:26:51,910
But the camshaft isn't always over the heads.

470
00:26:51,910 --> 00:26:53,878
Sometimes it lives in the block.

471
00:26:54,613 --> 00:26:57,115
Many of those engines will use push rods,

472
00:26:57,115 --> 00:27:00,418
basically metal sticks which ride on the cams,

473
00:27:00,719 --> 00:27:03,922
and then they stick up into the head so that as the cams

474
00:27:04,089 --> 00:27:06,558
rotate and the lobe pushes up on the stick,

475
00:27:06,925 --> 00:27:09,961
the push rod will actuate itself against a rocker arm,

476
00:27:09,961 --> 00:27:11,863
which then pushes down on the valves.

477
00:27:12,597 --> 00:27:17,936
Those engines aren't that common these days because putting the cams over the heads has a lot of advantages.

478
00:27:18,837 --> 00:27:22,507
Oh, and not every engine will use a timing chain.

479
00:27:23,241 --> 00:27:28,180
For some reason we decided 
to start using timing belts made of rubber.

480
00:27:29,347 --> 00:27:31,149
Okay, the reason was

481
00:27:31,149 --> 00:27:33,151
that it made engines a little quieter

482
00:27:33,251 --> 00:27:34,953
and it's not completely without merit.

483
00:27:34,953 --> 00:27:39,491
But don't get me started on Ford's wet timing belt situation.

484
00:27:39,791 --> 00:27:43,695
Just an utterly terrible idea
they should be shamed for forever!

485
00:27:44,596 --> 00:27:49,632
Regardless, engines with timing belts 
need regular replacement of that belt,

486
00:27:49,632 --> 00:27:53,138
because many engines are what's called an interference engine,

487
00:27:53,405 --> 00:27:58,677
where the valves will actually occupy 
the same physical space in the cylinder when they are open

488
00:27:58,943 --> 00:28:00,945
that the pistons do when they're at the top.

489
00:28:01,746 --> 00:28:03,815
So long as the engine is in time,

490
00:28:03,815 --> 00:28:07,185
this doesn't matter because the pistons 
won't be near the valves when they're open.

491
00:28:07,552 --> 00:28:10,221
But if the timing belt were to break

492
00:28:10,221 --> 00:28:15,126
and the cams stop turning with a valve open 
and sticking down into the cylinder,

493
00:28:15,794 --> 00:28:21,499
then as the crankshaft keeps on rotating, 
its respective piston will slam into that stuck valve

494
00:28:21,866 --> 00:28:24,536
and cause lots of very expensive damage.

495
00:28:25,537 --> 00:28:30,075
You don't want that, so you have to change 
the timing belt before it might break.

496
00:28:31,076 --> 00:28:36,981
Timing chains are much, much 
less likely to break, but they can fail.

497
00:28:37,382 --> 00:28:39,551
Usually, though, it's not catastrophic.

498
00:28:39,884 --> 00:28:44,740
Instead, they simply start to stretch out a bit due to the links wearing down,

499
00:28:44,740 --> 00:28:49,360
which makes valve timing sloppy, 
but not necessarily bad enough to be a problem.

500
00:28:50,195 --> 00:28:54,199
Though if it does get bad enough to where the chain skips a tooth,

501
00:28:54,833 --> 00:28:58,737
replacing a timing chain is a lot more involved than a belt,

502
00:28:58,737 --> 00:29:00,705
so there is that to consider.

503
00:29:02,040 --> 00:29:05,443
Right, and some pushrod engines don't use a belt or a chain.

504
00:29:05,844 --> 00:29:08,446
If the camshaft is close enough to the crankshaft,

505
00:29:08,446 --> 00:29:10,882
you can simply use interlocking gears.

506
00:29:11,516 --> 00:29:15,420
But again, pushrod engines in cars 
are pretty much a relic of the past,

507
00:29:15,420 --> 00:29:17,021
with some notable exceptions.

508
00:29:17,889 --> 00:29:21,292
Oh, and also there's flathead engines where 
the valves aren't even in the heads.

509
00:29:21,292 --> 00:29:25,230
But those are very old designs, 
and this rabbit hole is very, very deep.

510
00:29:25,230 --> 00:29:26,765
And eventually you just have to stop.

511
00:29:27,532 --> 00:29:28,733
Speaking of stop...

512
00:29:28,933 --> 00:29:30,535
At this point, you're probably wondering

513
00:29:30,535 --> 00:29:32,437
how any of this relates to the intro

514
00:29:32,437 --> 00:29:35,373
and the thing about that little red light
with a picture of an oiling can.

515
00:29:36,574 --> 00:29:40,411
Well, everything we've been talking about is made of metal.

516
00:29:41,112 --> 00:29:45,683
There's metal on metal contact everywhere inside this engine,

517
00:29:45,683 --> 00:29:49,420
and those bits of metal spin really, really fast.

518
00:29:50,021 --> 00:29:51,623
Or in the case of the pistons,

519
00:29:52,056 --> 00:29:55,760
those bits of metal slide against each other really, really fast.

520
00:29:55,927 --> 00:30:02,667
And that's going to cause a lot of damage 
unless you have lots and lots of lubrication.

521
00:30:03,368 --> 00:30:05,603
And that is what engine oil is for.

522
00:30:06,371 --> 00:30:10,475
Hanging off the bottom of the 
engine block is what's called the oil pan.

523
00:30:10,708 --> 00:30:12,844
And this is effectively just a big bucket

524
00:30:12,944 --> 00:30:15,513
which holds several quarts of motor oil.

525
00:30:16,414 --> 00:30:18,750
Well, this engine has a weird design

526
00:30:18,750 --> 00:30:21,019
and the block is split into two pieces.

527
00:30:21,019 --> 00:30:23,922
So it doesn't really have an oil pan per se,

528
00:30:23,922 --> 00:30:25,623
but the gist is the same.

529
00:30:26,124 --> 00:30:29,394
This bottom half of the block alongside a plate,

530
00:30:29,394 --> 00:30:32,556
which is the closest thing to an oil pan this engine has,

531
00:30:32,556 --> 00:30:35,099
holds just about four liters of oil.

532
00:30:35,767 --> 00:30:40,805
Apparently its precise oil capacity is four and 3/8 of a US quart.

533
00:30:41,639 --> 00:30:45,210
And sitting below the crankshaft inside the oil pan

534
00:30:46,311 --> 00:30:48,213
is this thing: the oil pump.

535
00:30:48,980 --> 00:30:52,183
every engine which isn't a tiny little thing for like a lawnmower,

536
00:30:52,483 --> 00:30:57,355
has an oil pump and in this one it's driven 
by the crankshaft via a second chain.

537
00:30:58,156 --> 00:31:02,060
So long as the crankshaft is spinning, the oil pump will be too.

538
00:31:02,327 --> 00:31:06,931
And what this does is suck engine oil 
out of this pan with this pickup tube,

539
00:31:07,131 --> 00:31:09,968
force it through a filter to catch any contaminants,

540
00:31:09,968 --> 00:31:12,570
and from there, the oil gets sent through many,

541
00:31:12,837 --> 00:31:16,541
many tiny little holes and passageways throughout the engine.

542
00:31:17,475 --> 00:31:20,979
Look closely at practically any part of an engine which moves,

543
00:31:20,979 --> 00:31:27,252
and somewhere along the mating surface, you're going to find a hole which eventually leads back to the oil pump.

544
00:31:28,152 --> 00:31:30,788
There are so many holes because when an engine is running,

545
00:31:31,089 --> 00:31:34,811
oil is getting forcefully sprayed all over the dang place.

546
00:31:34,811 --> 00:31:40,510
in fact, if you were wondering 
what some of these other holes in the head gasket were for,

547
00:31:40,510 --> 00:31:45,203
well, some of these deliver oil under pressure 
from the block and into the cylinder head

548
00:31:45,203 --> 00:31:48,039
so that it can lubricate the bearings of the camshafts

549
00:31:48,172 --> 00:31:51,276
as well as the cam lobes as they slide along the valves.

550
00:31:51,910 --> 00:31:55,046
That's why there's oil oozing out of different places in this footage.

551
00:31:55,847 --> 00:31:57,548
Some of the other holes in this head gasket

552
00:31:57,548 --> 00:32:01,019
allow that oil to return to the oil pan with the help of gravity,

553
00:32:01,419 --> 00:32:03,655
though other holes are for engine coolant,

554
00:32:03,988 --> 00:32:05,623
which we won't be talking about today.

555
00:32:06,624 --> 00:32:10,595
Regardless, let's take a close 
look at the block and crankshaft bearings

556
00:32:10,595 --> 00:32:13,464
because they reveal how this works the best.

557
00:32:13,698 --> 00:32:17,969
This port with an orange O-ring on it
is where oil is fed from the pump.

558
00:32:18,703 --> 00:32:20,505
Once it finds its way in the block,

559
00:32:20,505 --> 00:32:23,708
the oil flows through a series of tubes,

560
00:32:23,708 --> 00:32:26,244
and you can sort of make out the shape of these tubes

561
00:32:26,244 --> 00:32:28,780
and how it tees off here in both directions

562
00:32:28,780 --> 00:32:31,149
by looking at the casting of the block.

563
00:32:32,150 --> 00:32:35,019
If we look at the main bearing surfaces in the block,

564
00:32:35,253 --> 00:32:38,122
we'll see that there's a hole in each one of its bushings.

565
00:32:38,790 --> 00:32:42,226
If I remove the bushing, we'll find another larger hole behind it.

566
00:32:43,094 --> 00:32:49,100
The oil pump forces a steady stream of oil through those holes whenever the crankshaft is spinning,

567
00:32:49,467 --> 00:32:51,569
and that creates a fluid bearing.

568
00:32:52,337 --> 00:32:56,908
Once there's oil pressure, the metal surfaces 
aren't actually touching each other.

569
00:32:57,041 --> 00:33:01,579
Instead, they glide past each other with a thin film of oil between them.

570
00:33:02,480 --> 00:33:05,516
That's how the bearings allow the engine to spin smoothly

571
00:33:05,817 --> 00:33:08,586
despite the fact that they're literally just two pieces of metal.

572
00:33:09,554 --> 00:33:13,391
But you'll notice that there's a channel 
or groove cut into the bushing here.

573
00:33:14,125 --> 00:33:18,963
that is there to create a pathway for engine oil 
to make its way around the bearing

574
00:33:19,230 --> 00:33:21,399
and into the crankshaft itself.

575
00:33:22,333 --> 00:33:24,836
Notice that the bearing also has a hole.

576
00:33:25,503 --> 00:33:28,373
That hole will move around as the engine spins,

577
00:33:28,673 --> 00:33:30,975
but it will always be above that groove

578
00:33:30,975 --> 00:33:33,878
and so will always be fed oil from the block.

579
00:33:34,645 --> 00:33:37,148
And here we can actually see where the hole leads:

580
00:33:37,615 --> 00:33:42,186
another hole on another bearing; the bearing 
that the connecting rod attaches to.

581
00:33:42,954 --> 00:33:46,457
This is so that those bearings also get lots of lubrication

582
00:33:46,657 --> 00:33:49,694
and we get that fluid bearing effect
which keeps the metals from touching.

583
00:33:50,461 --> 00:33:52,864
Which by the way in case it's not clear

584
00:33:52,864 --> 00:33:57,435
oil is only under pressure inside 
all those passageways and ports and stuff.

585
00:33:58,202 --> 00:34:00,338
There's a whole bunch more of them too which I haven't covered

586
00:34:00,338 --> 00:34:03,341
inside the cylinder head to keep the camshafts lubricated

587
00:34:03,541 --> 00:34:05,410
as well as the moving parts of the valves.

588
00:34:06,044 --> 00:34:08,446
But once the oil makes its way out of whatever

589
00:34:08,446 --> 00:34:10,481
confined space it used to be in,

590
00:34:10,848 --> 00:34:12,950
it will just sort of ooze out.

591
00:34:12,950 --> 00:34:15,720
And then it's got to get back to the bottom of the engine

592
00:34:15,720 --> 00:34:17,655
so the oil pump can suck it up again.

593
00:34:18,256 --> 00:34:21,092
So there is also a series of pathways throughout the engine

594
00:34:21,092 --> 00:34:25,263
that will simply return any pooling oil to the bottom via gravity.

595
00:34:25,863 --> 00:34:30,435
And that's why internal combustion engines 
need to be close to upright to operate.

596
00:34:31,069 --> 00:34:34,138
If I were to turn this engine upside down and try and operate it,

597
00:34:34,605 --> 00:34:36,707
or frankly, even on its side like it is now,

598
00:34:37,008 --> 00:34:41,879
oil would be pooling in places it shouldn't 
go and the oil pump won't be able to get it.

599
00:34:41,879 --> 00:34:43,714
And so the lubrication system just...

600
00:34:44,916 --> 00:34:46,117
wouldn't work.

601
00:34:46,617 --> 00:34:52,623
And that's bad because everything 
inside this engine moves stupidly fast.

602
00:34:53,191 --> 00:34:57,195
If for whatever reason, the engine were to lose oil pressure,

603
00:34:57,862 --> 00:35:00,431
then suddenly you have a very big problem.

604
00:35:00,965 --> 00:35:05,692
That nice fluid bearing effect you get which keeps the metal parts from actually touching each other

605
00:35:05,692 --> 00:35:12,243
will go away and now... metal parts 
are rubbing against each other very quickly,

606
00:35:12,677 --> 00:35:14,779
and that's going to produce a lot of friction,

607
00:35:14,779 --> 00:35:16,280
which will produce a lot of heat.

608
00:35:16,681 --> 00:35:19,083
And before long the engine will seize,

609
00:35:19,283 --> 00:35:23,654
meaning parts get fuzed together 
and it can no longer spin at all.

610
00:35:24,822 --> 00:35:27,692
It is possible to get a seized engine unstuck,

611
00:35:28,059 --> 00:35:30,561
but it will definitely be damaged in some way

612
00:35:30,561 --> 00:35:33,264
and will likely have a greatly shortened lifespan.

613
00:35:33,598 --> 00:35:37,540
So you never, ever, ever, ever want to run an engine

614
00:35:37,540 --> 00:35:41,839
without knowing that there is sufficient 
oil pressure to keep that from happening.

615
00:35:42,773 --> 00:35:45,076
And that is what that light is for.

616
00:35:45,643 --> 00:35:50,014
It's connected to a pressure switch
which in its resting state is closed.

617
00:35:50,615 --> 00:35:53,084
In other words, when there is no oil pressure,

618
00:35:53,384 --> 00:35:56,354
that switch completes a circuit which lights up that light.

619
00:35:57,388 --> 00:35:59,123
This is what the pressure switch looks like.

620
00:35:59,690 --> 00:36:01,159
It's an unassuming little thing.

621
00:36:01,893 --> 00:36:03,361
Once the engine is turning,

622
00:36:03,361 --> 00:36:06,831
the oil pump will start forcing oil into all those passageways.

623
00:36:07,098 --> 00:36:11,235
And this port on the side is tapped off of those passages.

624
00:36:11,903 --> 00:36:17,141
So sufficient oil pressure will open this 
pressure switch and extinguish the warning light.

625
00:36:17,909 --> 00:36:21,479
This design allows you to check that the pressure switch is actually functional,

626
00:36:21,879 --> 00:36:24,715
because if you simply turn the key without cranking the engine,

627
00:36:25,049 --> 00:36:26,918
you should see the oil pressure light.

628
00:36:27,552 --> 00:36:29,787
There's no oil pressure yet because the engine isn't running!

629
00:36:30,555 --> 00:36:32,423
But when you start the engine,

630
00:36:32,590 --> 00:36:35,059
that light should go out almost immediately.

631
00:36:35,560 --> 00:36:38,129
And if it doesn't, there's a problem.

632
00:36:38,963 --> 00:36:42,066
That problem isn't necessarily with the engine, of course.

633
00:36:42,066 --> 00:36:44,402
It could simply be a bad pressure switch.

634
00:36:45,236 --> 00:36:48,206
But that's a really risky assumption to make

635
00:36:48,472 --> 00:36:51,842
because if that light and the switch is working as it should,

636
00:36:52,510 --> 00:36:55,313
then if the light comes on, you are

637
00:36:55,313 --> 00:36:59,217
then running your engine without oil pressure, which will kill it.

638
00:37:00,017 --> 00:37:03,988
Oh, and fun fact eagle-eyed viewers 
of the catalytic converter video

639
00:37:04,021 --> 00:37:07,692
may have noticed that this car had a bad pressure switch,

640
00:37:07,959 --> 00:37:09,260
but it failed open.

641
00:37:09,927 --> 00:37:11,963
The oil pressure light was never coming on

642
00:37:11,963 --> 00:37:13,431
even without the engine running.

643
00:37:13,931 --> 00:37:17,368
Here's me turning the key and that light is nowhere to be seen.

644
00:37:18,236 --> 00:37:21,939
This meant the car could never warn me that I've lost oil pressure,

645
00:37:22,240 --> 00:37:26,544
which isn't as bad as actually losing oil pressure, 
of course, but it's still quite bad.

646
00:37:27,411 --> 00:37:30,915
Luckily, I happened to buy this entire engine for making videos

647
00:37:30,915 --> 00:37:32,883
and it had its own oil pressure switch on there,

648
00:37:33,317 --> 00:37:34,619
so I just swapped them over.

649
00:37:34,619 --> 00:37:36,821
And now that light is actually doing its job.

650
00:37:37,822 --> 00:37:38,589
Quick side note,

651
00:37:38,589 --> 00:37:41,993
a lot of older cars didn't have an oil pressure warning light

652
00:37:41,993 --> 00:37:44,262
and instead had an oil pressure gauge,

653
00:37:44,762 --> 00:37:48,933
but that's mostly gone, 
much to the chagrin of John Davis of MotorWeek.

654
00:37:49,734 --> 00:37:52,069
Some new vehicles still have oil pressure gauges,

655
00:37:52,069 --> 00:37:54,672
but they're mainly found in big trucks

656
00:37:54,672 --> 00:37:59,610
because getting to see an engine oil pressure readout makes some people feel big and manly and important.

657
00:38:01,012 --> 00:38:05,249
But I mean, most people don't really care

658
00:38:05,249 --> 00:38:08,552
how much oil pressure an engine 
is producing at any given moment.

659
00:38:08,552 --> 00:38:11,289
And without knowledge of how much is actually correct,

660
00:38:11,656 --> 00:38:13,724
a gauge isn't that useful anyway,

661
00:38:13,724 --> 00:38:17,161
and that's why a simple pressure switch 
and warning light which indicates

662
00:38:17,428 --> 00:38:21,332
"oil pressure is below a safe threshold," is frankly better.

663
00:38:22,333 --> 00:38:23,534
Yeah, I said it.

664
00:38:24,035 --> 00:38:26,370
Gearheads like to call these idiot lights

665
00:38:26,370 --> 00:38:30,641
because we used to expect people to know 
they should be checking the gauges frequently.

666
00:38:31,008 --> 00:38:34,011
In fact, some cars in the past had a little yellow warning light

667
00:38:34,011 --> 00:38:36,113
which literally said "check gauges."

668
00:38:37,048 --> 00:38:40,851
But while I too lament the loss 
of drivers being expected to know

669
00:38:41,052 --> 00:38:44,522
a little more about how their cars work than they seem to now,

670
00:38:44,989 --> 00:38:48,225
I think it's fair to say a warning light is all that's really needed,

671
00:38:48,225 --> 00:38:51,462
but you do need to know what that warning light means.

672
00:38:52,396 --> 00:38:56,100
On that note, why might you actually lose oil pressure?

673
00:38:57,234 --> 00:39:01,472
Well, it's very rare for it to suddenly just happen.

674
00:39:02,139 --> 00:39:04,175
I hope I haven't made it sound like this is something

675
00:39:04,175 --> 00:39:06,949
you need to be extremely vigilant about all the time,

676
00:39:06,949 --> 00:39:12,283
though you probably should watch the oil pressure 
light closely after you get an oil change,

677
00:39:12,316 --> 00:39:13,951
and I'll explain that further in a moment.

678
00:39:14,952 --> 00:39:17,088
If you're just driving around on a normal day, though,

679
00:39:17,521 --> 00:39:21,692
it's extremely unlikely
that your engine will suddenly lose oil pressure.

680
00:39:22,393 --> 00:39:26,030
That would really only happen 
if the oil pump were to somehow fail.

681
00:39:26,230 --> 00:39:30,534
And given that it's literally the most lubricated part
in the whole engine

682
00:39:30,534 --> 00:39:32,870
since it sits in oil and pumps it around,

683
00:39:33,571 --> 00:39:34,772
that's quite rare.

684
00:39:35,373 --> 00:39:37,975
It does happen, but it's extremely rare.

685
00:39:38,843 --> 00:39:41,645
However, if your engine burns oil,

686
00:39:41,979 --> 00:39:44,548
which it shouldn't, but it tends to start happening

687
00:39:44,548 --> 00:39:47,051
when an engine gets very old and worn out.

688
00:39:47,618 --> 00:39:49,754
Or if it wasn't designed very well,

689
00:39:50,121 --> 00:39:56,527
well then the amount of oil inside 
your engine slowly drops as you use your car.

690
00:39:57,528 --> 00:39:59,894
There's quite a good deal of margin for error,

691
00:39:59,894 --> 00:40:04,234
so losing a quart of oil between 
oil changes is not likely to cause a problem.

692
00:40:04,535 --> 00:40:07,671
But if your engine burns through a lot of oil,

693
00:40:08,072 --> 00:40:11,008
then eventually the oil level can get low enough

694
00:40:11,008 --> 00:40:15,312
that the oil pump starts to have trouble 
sucking any up through the intake tube.

695
00:40:16,313 --> 00:40:21,385
If this is happening, the oil pressure 
light will likely come on and off, seemingly at random.

696
00:40:22,353 --> 00:40:28,259
That is not as bad as not having 
any oil pressure at all, but it's still quite bad.

697
00:40:28,692 --> 00:40:32,696
The bearings inside the engine 
aren't always getting good oil flow,

698
00:40:32,963 --> 00:40:35,966
and they're going to start wearing 
out a lot faster than they should.

699
00:40:36,667 --> 00:40:41,505
So you probably need to add some oil to your engine 
if that light is coming on intermittently.

700
00:40:42,473 --> 00:40:49,180
But the most common reason you might one day lose 
oil pressure is when somebody makes a booboo.

701
00:40:49,780 --> 00:40:52,249
For example, you went in to get an oil change

702
00:40:52,249 --> 00:40:54,785
and the technician forgot to actually fill the engine

703
00:40:54,785 --> 00:40:57,555
with new oil after they drained the old oil out.

704
00:40:57,955 --> 00:41:00,024
Or maybe they forgot to put the drain plug back.

705
00:41:00,224 --> 00:41:01,892
Or perhaps they didn't tighten it enough

706
00:41:01,892 --> 00:41:04,028
and it backed itself out as you were driving

707
00:41:04,328 --> 00:41:06,964
and your car puked all of its oil onto the ground.

708
00:41:07,898 --> 00:41:10,901
To be clear, 
I don't want to make it sound like that happens all the time.

709
00:41:10,901 --> 00:41:13,637
But seriously, after you get an oil change,

710
00:41:13,637 --> 00:41:15,639
pay attention to that light for a while.

711
00:41:16,040 --> 00:41:21,111
You really want to make sure it goes out quickly 
once the engine turns over and stays out.

712
00:41:22,146 --> 00:41:23,414
But speaking of oil changes,

713
00:41:23,581 --> 00:41:25,749
this car is due for one, so let's do it!

714
00:41:26,050 --> 00:41:27,251
Why not?

715
00:41:27,952 --> 00:41:30,654
In fact, I have no idea whether it's actually due for one.

716
00:41:30,654 --> 00:41:32,990
But that's kind of why I'm doing it.

717
00:41:33,691 --> 00:41:36,660
Changing your own oil is actually quite easy,

718
00:41:36,660 --> 00:41:40,164
but I don't really recommend it because it's messy,

719
00:41:40,364 --> 00:41:42,165
you have to deal with the old oil

720
00:41:42,165 --> 00:41:45,636
(and yes, parts stores will take 
used oil for free, but it's still annoying),

721
00:41:46,136 --> 00:41:49,707
And, it honestly hardly saves any money.

722
00:41:49,707 --> 00:41:51,809
But why don't I show you the process?

723
00:41:52,543 --> 00:41:56,714
Actually, first, if you don't know why you have to change the oil

724
00:41:56,714 --> 00:42:00,184
every some thousand miles or so, well, here's why:

725
00:42:00,784 --> 00:42:02,319
The oil gets really hot

726
00:42:02,620 --> 00:42:04,688
and the piston rings aren't perfect.

727
00:42:05,556 --> 00:42:09,026
Remember, there's a whole bunch of explosions going on in here!

728
00:42:09,260 --> 00:42:11,896
Several every second, just at idle!

729
00:42:12,429 --> 00:42:15,980
And the intense pressure inside the cylinders means

730
00:42:15,980 --> 00:42:20,037
some combustion byproducts are going to end up getting past the piston rings

731
00:42:20,037 --> 00:42:25,042
and into the crankcase where they'll mix 
with the engine oil and start to contaminate it.

732
00:42:26,010 --> 00:42:29,079
That will eventually start to chemically break it down.

733
00:42:29,847 --> 00:42:31,248
And if that's not bad enough,

734
00:42:31,248 --> 00:42:35,019
the oil which clings to the cylinder walls gets extremely hot,

735
00:42:35,019 --> 00:42:37,939
which also causes chemical breakdown.

736
00:42:37,939 --> 00:42:41,759
Over time, this causes the oil to lose its lubricative properties,

737
00:42:42,293 --> 00:42:44,495
and that means your engine can start to wear.

738
00:42:45,329 --> 00:42:47,831
And if you're really overdue for an oil change,

739
00:42:48,065 --> 00:42:50,401
little bits of stuff can precipitate out

740
00:42:50,401 --> 00:42:53,237
of old engine oil and stick to things.

741
00:42:53,604 --> 00:42:55,105
That's engine sludge.

742
00:42:55,105 --> 00:42:58,275
And if it gets bad enough, it can start breaking things

743
00:42:58,275 --> 00:43:00,844
by plugging up those tiny oil passageways.

744
00:43:01,545 --> 00:43:07,251
So you gotta change your oil regularly to keep that from happening and to keep the engine healthy.

745
00:43:08,018 --> 00:43:13,357
I'm deliberately not commenting on how often 
you should do that because nobody agrees.

746
00:43:13,657 --> 00:43:20,064
But my basic advice is consult your owner's manual and maybe do it a little more often than it says you should.

747
00:43:21,065 --> 00:43:25,035
But I've got one of those 
electric cars and it doesn't need oil changes.

748
00:43:25,336 --> 00:43:26,537
How about that?

749
00:43:26,704 --> 00:43:28,105
But this one does.

750
00:43:28,339 --> 00:43:30,741
So first I'll get it up in the air a little bit.

751
00:43:31,542 --> 00:43:33,611
You don't need a lift to do this.

752
00:43:33,777 --> 00:43:35,946
If all you want to do is your own oil changes,

753
00:43:35,946 --> 00:43:39,650
you can purchase these ramps 
and drive the front of your car onto them,

754
00:43:39,650 --> 00:43:41,485
and that'll give you enough room to work with.

755
00:43:42,086 --> 00:43:44,755
There's two things you need access to from the bottom:

756
00:43:45,022 --> 00:43:47,157
the drain plug and the oil filter.

757
00:43:47,558 --> 00:43:50,194
Though in some cars the oil filter is somewhere else

758
00:43:50,194 --> 00:43:52,429
or possibly behind a cover of some sort.

759
00:43:53,230 --> 00:43:57,868
You'll also need something to catch 
the used oil with, like this purpose made drain pan.

760
00:43:58,602 --> 00:44:01,805
And then of course, you'll need new oil and a replacement filter.

761
00:44:02,506 --> 00:44:06,180
Here's a five quart bottle of the cheapest oil I found in the store,

762
00:44:06,180 --> 00:44:08,874
because this car is not worth getting fancy over,

763
00:44:08,874 --> 00:44:11,548
and here's a replacement filter which fits the car.

764
00:44:12,483 --> 00:44:13,617
Speaking of the oil,

765
00:44:13,617 --> 00:44:17,588
your car's engine is going to call for a specific oil viscosity,

766
00:44:17,588 --> 00:44:19,757
which some people refer to as its weight.

767
00:44:20,591 --> 00:44:25,062
The Society of Automotive Engineers came up with a way to define motor oil viscosity

768
00:44:25,095 --> 00:44:28,999
using a simple numbering scheme, and bigger numbers are more viscous.

769
00:44:29,933 --> 00:44:32,703
This car needs 5W-30 motor oil.

770
00:44:33,037 --> 00:44:34,471
And the cool thing about that

771
00:44:34,638 --> 00:44:38,375
is that this oil has two different viscosity grades.

772
00:44:38,942 --> 00:44:43,113
When the oil is cold, it has 
the same viscosity as a five weight oil.

773
00:44:43,681 --> 00:44:47,051
That's the 5W, and the W is for winter.

774
00:44:47,718 --> 00:44:49,286
But when the oil is hot

775
00:44:49,653 --> 00:44:52,356
it has the viscosity of a 30 weight oil.

776
00:44:53,590 --> 00:44:57,561
Now any oil loses viscosity and gets thinner as it gets hotter.

777
00:44:57,561 --> 00:44:58,762
And this is no different.

778
00:44:58,929 --> 00:45:02,700
But as the engine warms up, additives in this formulation

779
00:45:02,700 --> 00:45:04,968
slow down that thinning process.

780
00:45:05,269 --> 00:45:08,806
And that's how when it's hot, it has the same viscosity

781
00:45:08,806 --> 00:45:11,141
as an unmodified 30 weight oil.

782
00:45:11,909 --> 00:45:14,712
This is actually a really neat thing we figured out how to do.

783
00:45:14,878 --> 00:45:18,415
And it means the engine has 
an easier time starting when it's cold,

784
00:45:18,682 --> 00:45:22,619
but still has the same protection 
as a 30 weight oil once it's warmed up.

785
00:45:23,754 --> 00:45:26,724
Right. And the breakdown of those additives over time

786
00:45:26,724 --> 00:45:32,463
as the oil gets contaminated with combustion byproducts and whatnot, lowers the oil's viscosity grade.

787
00:45:32,730 --> 00:45:35,566
And that's yet another reason you need to change it periodically.

788
00:45:36,433 --> 00:45:40,437
So to do that, I'll start by draining the old oil from the engine.

789
00:45:40,871 --> 00:45:43,607
But first I'm going to remove the filler cap up top,

790
00:45:43,774 --> 00:45:46,410
which will allow that oil to leave the engine more quickly

791
00:45:46,410 --> 00:45:49,613
by breaking the vacuum and letting air into the top of the engine.

792
00:45:50,581 --> 00:45:54,318
Then I'll put the drain pan below the drain plug of the engine,

793
00:45:54,318 --> 00:45:56,220
but I'm going to position it off-center.

794
00:45:56,820 --> 00:45:58,155
You'll see why shortly.

795
00:45:58,956 --> 00:46:02,059
Quick note, the transmission will also have a drain plug,

796
00:46:02,059 --> 00:46:06,330
so make sure you know how to tell the engine and transmission apart before you drain the wrong thing.

797
00:46:07,564 --> 00:46:11,001
Next, I'll use a wrench to crack the drain plug loose.

798
00:46:11,201 --> 00:46:14,946
The engine is warmed up,
by the way, to make the oil flow more easily.

799
00:46:14,946 --> 00:46:17,942
with a gloved hand I'll then remove the plug.

800
00:46:18,609 --> 00:46:21,245
If you keep pressing in on it while you back it out,

801
00:46:21,478 --> 00:46:25,983
you can usually keep it from dripping any oil at all 
until you feel the threads start to click,

802
00:46:26,250 --> 00:46:30,587
and then you can simply yoink it out 
quickly and hopefully not get any on your hands.

803
00:46:31,355 --> 00:46:32,990
And now that it's flowing out of there,

804
00:46:33,457 --> 00:46:35,926
you can see why I didn't center the drain pan.

805
00:46:36,894 --> 00:46:40,297
As the old oil flows out, we'll deal with the oil filter.

806
00:46:40,998 --> 00:46:46,503
This style of oil filter has built in threads 
and simply screws onto a fitting on the engine block.

807
00:46:47,004 --> 00:46:49,072
Or in the case of this car,

808
00:46:49,106 --> 00:46:53,110
whatever you call this part,
which isn't really the block, but kind of is.

809
00:46:53,610 --> 00:46:57,481
Anyway, these should only be put on hand tight,

810
00:46:57,481 --> 00:47:00,184
which means they should come off easily,

811
00:47:00,350 --> 00:47:03,687
but should is carrying a lot of weight there.

812
00:47:03,987 --> 00:47:06,423
And that's why I have this oil filter wrench.

813
00:47:07,157 --> 00:47:09,293
Once it starts coming loose, keep in mind

814
00:47:09,293 --> 00:47:12,129
this thing is filled with oil and will be gross.

815
00:47:12,663 --> 00:47:15,098
Many drain pans like this one have a spot

816
00:47:15,098 --> 00:47:18,035
molded into them to put the used filter and let it drain out.

817
00:47:18,702 --> 00:47:22,306
And now I'll take the new filter and with my gloved hand,

818
00:47:22,506 --> 00:47:26,243
I'll smear just a little bit of the old oil onto the gasket

819
00:47:26,376 --> 00:47:28,245
before screwing it onto the engine.

820
00:47:28,979 --> 00:47:32,683
And again, this should only go on hand tight.

821
00:47:33,550 --> 00:47:38,255
By the way, these claim to last long enough to only change the filter every other oil change.

822
00:47:38,555 --> 00:47:41,225
But these are like five bucks,
so you might as well just change it.

823
00:47:41,625 --> 00:47:45,796
Its job is to trap
things like metal shavings and keep them in the filter

824
00:47:45,896 --> 00:47:48,198
before they plug up all those little parts and stuff,

825
00:47:48,198 --> 00:47:49,466
which would be very bad.

826
00:47:49,466 --> 00:47:51,668
So I don't think it's worth risking it.

827
00:47:51,668 --> 00:47:52,870
Just replace it.

828
00:47:53,403 --> 00:47:58,508
By this point, the engine is probably almost done 
draining the old oil out of itself.

829
00:47:58,809 --> 00:48:02,179
But if for some reason it's still flowing, let it flow.

830
00:48:02,913 --> 00:48:06,617
Once it's down to barely a trickle, 
though you can put the drain plug back.

831
00:48:07,184 --> 00:48:10,921
Ideally, you'd replace this crush washer which seals that hole,

832
00:48:11,355 --> 00:48:14,825
but I did not get a replacement, so I will be reusing the old one

833
00:48:15,692 --> 00:48:17,895
Once I've started threading the plug by hand,

834
00:48:18,028 --> 00:48:19,696
I'll then reach for an impact wrench.

835
00:48:20,397 --> 00:48:21,598
Except I'm joking.

836
00:48:21,632 --> 00:48:24,201
Don't ever use power tools for this.

837
00:48:24,568 --> 00:48:26,937
If you screw up the threads on the oil pan,

838
00:48:26,937 --> 00:48:30,674
this oil change went from an easy job to a very bad day.

839
00:48:30,908 --> 00:48:35,145
So only use hand tools when dealing with drain plugs.

840
00:48:35,646 --> 00:48:37,814
I even looked up the torque spec for this guy.

841
00:48:37,948 --> 00:48:41,652
It's 34.3 Newton meters or 25 pound feet.

842
00:48:42,052 --> 00:48:46,470
And I used this old torque wrench which I have 
no idea whether it's well calibrated or not at this point,

843
00:48:46,470 --> 00:48:46,970
but hey.

844
00:48:47,124 --> 00:48:48,507
It's the thought that counts.

845
00:48:48,507 --> 00:48:49,459
[click]

846
00:48:50,327 --> 00:48:51,995
And now we're done down here.

847
00:48:52,462 --> 00:48:57,067
But we're very much not done done 
because the engine no longer has any oil in it!

848
00:48:58,268 --> 00:49:01,972
Well, it probably has about half a quart stuck in there 
based on how much of a mess

849
00:49:01,972 --> 00:49:04,207
this one made when getting some of this footage,

850
00:49:04,775 --> 00:49:07,444
but it's definitely not enough for it to run without damage.

851
00:49:07,778 --> 00:49:10,013
If I were to start it now, that would be very bad.

852
00:49:10,480 --> 00:49:13,350
Oh, fun fact, did you know engines are dishwasher safe?

853
00:49:13,984 --> 00:49:16,620
The dishwasher would not agree, but, uh,

854
00:49:16,620 --> 00:49:18,153
it did clean it.

855
00:49:18,153 --> 00:49:18,989
Anyway,

856
00:49:19,056 --> 00:49:21,925
now we have to put new oil into the engine,

857
00:49:21,925 --> 00:49:23,527
which is done via the filler cap.

858
00:49:24,127 --> 00:49:28,098
This is literally just a big hole that leads into the timing cover.

859
00:49:28,365 --> 00:49:30,567
Look, you can even see the timing chain a little bit.

860
00:49:31,435 --> 00:49:35,615
Pour new oil into here and it will fall down into the oil pan...

861
00:49:35,615 --> 00:49:38,875
or whatever this is- let's just call it the oil sump.

862
00:49:39,710 --> 00:49:43,347
However, this car will not need this entire bottle of oil.

863
00:49:43,647 --> 00:49:46,583
In fact, it would be overfilled if I put the whole thing in

864
00:49:46,850 --> 00:49:50,454
and an engine with too much oil is also a problem.

865
00:49:51,154 --> 00:49:53,323
So I'll put most of it in there,

866
00:49:53,323 --> 00:49:56,827
but then I'll have to check how much oil is inside using the dipstick.

867
00:49:57,461 --> 00:49:59,830
Which is literally just a stick in a tube.

868
00:50:00,063 --> 00:50:02,599
And that tube leads to the engine's oil sump.

869
00:50:03,133 --> 00:50:05,035
The stick has markings on the end,

870
00:50:05,302 --> 00:50:08,271
and once you've cleaned it using a rag or paper towel or whatever,

871
00:50:08,271 --> 00:50:12,343
you'll stick it down into the tube 
all the way and then pull it back out.

872
00:50:13,076 --> 00:50:16,146
The tip of the stick should have poked down into the oil,

873
00:50:16,146 --> 00:50:18,949
and you'll be able to see the oil level when you pull it out.

874
00:50:19,850 --> 00:50:22,452
If you're not seeing any oil towards the markings,

875
00:50:22,786 --> 00:50:26,690
you're probably still about a quart shy 
and you'll need to add a good deal more.

876
00:50:27,524 --> 00:50:31,862
Just keep adding a little bit at a time, though, 
and repeat the oil level check process,

877
00:50:31,862 --> 00:50:34,398
and eventually you'll start to see the oil in the range.

878
00:50:34,998 --> 00:50:37,968
I'm going to shoot for just below the full mark,

879
00:50:37,968 --> 00:50:39,236
which will account for any oil

880
00:50:39,236 --> 00:50:41,605
which might be sticking to the timing chain and junk.

881
00:50:42,414 --> 00:50:43,874
And once it's full,

882
00:50:44,441 --> 00:50:46,176
well that's an oil change.

883
00:50:46,610 --> 00:50:48,345
It's really quite straightforward.

884
00:50:48,812 --> 00:50:52,949
Now all that's left to do besides dealing 
with the used oil and filter, of course,

885
00:50:53,316 --> 00:50:56,286
is to put the oil cap back on and start the engine.

886
00:50:56,920 --> 00:51:00,824
But now a note on prefilling the oil filter.

887
00:51:01,558 --> 00:51:04,461
Some people insist that you should fill the oil filter

888
00:51:04,461 --> 00:51:06,963
with clean oil before putting it on to the engine.

889
00:51:07,931 --> 00:51:12,933
The theory is that this oil filter 
is currently filled with air and not oil,

890
00:51:12,933 --> 00:51:14,471
and so when I start the engine,

891
00:51:14,704 --> 00:51:18,442
there will be a brief moment 
where the engine is running without oil pressure.

892
00:51:19,709 --> 00:51:23,113
But personally, I think this is a very silly thing to obsess over.

893
00:51:24,147 --> 00:51:25,087
Why?

894
00:51:25,087 --> 00:51:27,951
Well, because not only is the oil filter filled with air right now,

895
00:51:27,951 --> 00:51:30,854
but so is every single one of the passageways inside the engine.

896
00:51:31,655 --> 00:51:33,256
So forgive me for not thinking

897
00:51:33,256 --> 00:51:35,959
filling this with oil is going to make a huge difference.

898
00:51:37,027 --> 00:51:41,164
Granted, this engine has a tiny little filter 
and some engines have much bigger ones.

899
00:51:41,698 --> 00:51:43,767
But why don't we take a look at how quickly

900
00:51:43,767 --> 00:51:46,336
that oil pressure light goes out once I start the engine?

901
00:51:47,104 --> 00:51:47,637
Okay.

902
00:51:47,637 --> 00:51:48,839
I just changed the oil.

903
00:51:48,839 --> 00:51:50,000
Let's crank it up.

904
00:51:50,000 --> 00:51:51,665
[engine starts]

905
00:51:54,978 --> 00:51:55,846
Yeah.

906
00:51:55,846 --> 00:51:57,447
What, one second?

907
00:51:58,348 --> 00:51:59,516
One extra second.

908
00:51:59,516 --> 00:52:00,851
It's not a big deal.

909
00:52:01,151 --> 00:52:04,321
I mean, you go ahead and fill these things with oil if you want to,

910
00:52:04,321 --> 00:52:09,526
but I feel like doing that is just creating 
another mess which isn't doing much if anything at all.

911
00:52:10,227 --> 00:52:13,230
The film of old oil that's sticking to the bearings, etc.

912
00:52:13,597 --> 00:52:17,033
is going to be enough to prevent damage in the 2 or 3 seconds

913
00:52:17,033 --> 00:52:20,804
it takes the oil pump to fill even a really big oil filter.

914
00:52:21,938 --> 00:52:28,545
Regardless, now that the engine is running, it's prudent to check the oil filter and drain plug for any signs of leaks.

915
00:52:29,279 --> 00:52:30,614
And assuming there are none,

916
00:52:31,114 --> 00:52:32,315
you're done!

917
00:52:32,582 --> 00:52:34,718
We've looked at a great deal of stuff today,

918
00:52:34,718 --> 00:52:38,922
but we've just been looking at 
the basic mechanical parts of the engine.

919
00:52:39,756 --> 00:52:42,359
Yeah, there are a whole lot of spinny bits in there,

920
00:52:42,359 --> 00:52:45,162
and they all need lots of lube to keep on spinning,

921
00:52:45,395 --> 00:52:49,799
but they don't start spinning unless 
a whole lot of other stuff happens.

922
00:52:50,300 --> 00:52:54,171
For instance, we need to deliver 
fuel to the combustion chambers,

923
00:52:54,171 --> 00:52:56,973
and we need to ignite that fuel with a spark plug.

924
00:52:58,141 --> 00:53:00,310
We use a computer to do those things,

925
00:53:00,310 --> 00:53:02,245
and we've been doing that for decades now.

926
00:53:02,712 --> 00:53:05,215
But the computer needs to know

927
00:53:05,215 --> 00:53:08,852
precisely where each part of this engine is,

928
00:53:08,985 --> 00:53:11,955
so it can tell when it should do those things.

929
00:53:12,956 --> 00:53:17,227
In the next video on 
engine management tech, we'll be looking closely at,

930
00:53:17,727 --> 00:53:20,096
well, that part, the management part,

931
00:53:20,564 --> 00:53:24,367
because while this is a very intricate
and fascinating piece of machinery,

932
00:53:24,834 --> 00:53:28,138
it is literally useless without the digital system

933
00:53:28,138 --> 00:53:30,840
which controls the spark plugs, the fuel injectors

934
00:53:31,074 --> 00:53:33,476
and even the intake valve timing.

935
00:53:34,444 --> 00:53:37,180
I'll be covering all of that in the next video in this series,

936
00:53:37,647 --> 00:53:39,341
so stay tuned.

937
00:53:40,196 --> 00:53:42,723
♫ load-bearingly smooth jazz ♫

938
00:53:43,360 --> 00:53:45,360
[whirring sound is increasing in speed]

939
00:53:45,834 --> 00:53:46,334
[schwoop]

940
00:53:46,334 --> 00:53:47,002
[banging]

941
00:53:47,221 --> 00:53:48,581
[comically metallic crash]

942
00:53:48,858 --> 00:53:50,126
It's fine!

943
00:53:50,760 --> 00:53:51,928
It's fine.

944
00:53:51,928 --> 00:53:52,996
Nothing happened.

945
00:53:52,996 --> 00:53:54,698
It just fell off the table.

946
00:53:54,698 --> 00:53:55,899
It's fine.

947
00:53:56,233 --> 00:54:01,504
This is the crank pulley and it provides power for the engine accessories.

948
00:54:02,706 --> 00:54:03,907
That's not working.

949
00:54:04,374 --> 00:54:08,378
and it provides power for engine accessories such as the alternator,

950
00:54:08,411 --> 00:54:09,846
the air conditioning compressor...

951
00:54:12,215 --> 00:54:13,883
I thought you would behave a little better.

952
00:54:13,883 --> 00:54:15,752
You didn't. You didn't.

953
00:54:16,375 --> 00:54:18,375
[oh no here we go again]

954
00:54:20,746 --> 00:54:22,746
[the sounds weren't as funny this time]

955
00:54:23,059 --> 00:54:24,361
It's fine.

956
00:54:24,594 --> 00:54:26,029
Nothing happened.

957
00:54:26,563 --> 00:54:27,764
It's fine.

958
00:54:28,649 --> 00:54:33,009
So now I guess I need to start plotting my atonement for the bearing/journal decision.

959
00:54:33,009 --> 00:54:35,072
Does one plot an atonement?

960
00:54:35,072 --> 00:54:36,348
Well that's not important right now.

961
00:54:36,348 --> 00:54:42,745
What is important is that you imagine the animated character Doug Funnie writing in his bearing.

962
00:54:43,374 --> 00:54:45,315
For some of you, that hurt.