WEBVTT Kind: captions Language: en 00:00:00.000 --> 00:00:04.904 If there's one light on your car's instrument panel you should never, ever ignore, 00:00:05.338 --> 00:00:06.506 it's this one: 00:00:06.506 --> 00:00:08.108 the oil pressure warning light. 00:00:08.875 --> 00:00:10.944 It usually looks like a little oiling can. 00:00:11.277 --> 00:00:13.713 And if that light comes on while you're driving, 00:00:14.114 --> 00:00:19.786 that means you should pull over and shut off the engine as soon as you can possibly do so safely 00:00:19.786 --> 00:00:21.154 and then call a tow truck. 00:00:21.821 --> 00:00:23.023 And I'm not kidding. 00:00:23.023 --> 00:00:24.424 If that light comes on, 00:00:24.591 --> 00:00:28.862 your engine may be mere minutes away from self-destruction. 00:00:29.229 --> 00:00:32.732 And so continuing to drive is a very risky choice to make. 00:00:33.767 --> 00:00:39.305 Now, if you're wondering why exactly the engine could destroy itself when that light comes on, 00:00:39.706 --> 00:00:41.241 that's the point of this video. 00:00:41.775 --> 00:00:45.979 Today we're going to explore the mechanical basics of the internal combustion engine, 00:00:46.212 --> 00:00:52.152 with a particular focus on its lubrication system and why it's required to keep the engine alive. 00:00:53.086 --> 00:00:57.757 There's a lot of stuff going on inside one of these contraptions, and by the time we're done here 00:00:57.924 --> 00:01:03.997 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. 00:01:04.831 --> 00:01:07.834 Now, if you're a gearhead or even just gearhead-adjacent, 00:01:08.501 --> 00:01:10.403 there's probably not much you're going to learn here. 00:01:10.904 --> 00:01:14.507 But if you don't really know that much about engines and how they work, 00:01:14.741 --> 00:01:17.549 and really how they keep themselves working, 00:01:17.954 --> 00:01:20.513 well I think you'll find this video to be quite informative. 00:01:21.247 --> 00:01:22.816 Before we really dive in, though, 00:01:22.916 --> 00:01:26.886 there's something you should know about the rest of the lights on your car's instrument cluster. 00:01:27.454 --> 00:01:30.056 And that's something is the rest of them! 00:01:30.356 --> 00:01:34.627 Because they all mean very important things and are designed to help you. 00:01:35.128 --> 00:01:38.331 They're even color coded to convey their urgency and meaning. 00:01:39.065 --> 00:01:42.735 Red lights are bad and need your attention now 00:01:43.103 --> 00:01:47.373 because they indicate an unsafe condition where something is majorly wrong. 00:01:48.241 --> 00:01:51.511 Yellow lights are warnings which can vary in severity 00:01:51.678 --> 00:01:54.280 but probably don't need your immediate attention. 00:01:55.014 --> 00:01:58.284 And other colors are usually reserved for simple information, 00:01:58.618 --> 00:02:01.553 like the blue light that warns you your high beams are on 00:02:01.553 --> 00:02:06.392 so please shut them off unless you're in the middle of the country — that's not for use with other cars around! 00:02:06.960 --> 00:02:10.864 Or the white or green status indicators for the cruise control system. 00:02:11.731 --> 00:02:14.601 If you want to know just what exactly all those lights mean, 00:02:14.901 --> 00:02:17.036 your car will have an owner's manual somewhere 00:02:17.270 --> 00:02:22.642 and there's going to be a handy little section which explains each and every one of them and why they might light up. 00:02:23.510 --> 00:02:26.613 I'd highly encourage looking at that section of the manual 00:02:26.613 --> 00:02:28.381 and committing those details to memory. 00:02:29.282 --> 00:02:32.752 But anyway, this is a video about the engine and how it works. 00:02:32.785 --> 00:02:34.435 So let's dig into it. 00:02:34.435 --> 00:02:35.989 First, though, if you'll indulge me, 00:02:36.422 --> 00:02:39.840 here's a brief overview of how electric cars work: 00:02:39.840 --> 00:02:41.235 [two toots of the drill] 00:02:41.561 --> 00:02:42.695 But bigger. 00:02:42.695 --> 00:02:46.599 And now let's take a look at this Renault-Nissan MR-18DE, 00:02:46.833 --> 00:02:49.836 the engine which powers the venerable Nissan Cube. 00:02:50.703 --> 00:02:52.605 Let me just, uh, take it apart real quick. 00:02:59.679 --> 00:03:00.880 Okay, 00:03:01.614 --> 00:03:03.349 this is the engine block. 00:03:03.816 --> 00:03:07.754 It's really nothing more than an intricately cast and machined hunk of metal, 00:03:08.121 --> 00:03:11.391 but it's the heart of the engine and contains the cylinders. 00:03:11.958 --> 00:03:13.459 In this case, there are four of them, 00:03:13.459 --> 00:03:15.195 and they're all arranged in a straight line, 00:03:15.328 --> 00:03:17.964 which makes this an inline four cylinder engine. 00:03:18.264 --> 00:03:21.401 Probably the most common type of engine out there in cars. 00:03:22.368 --> 00:03:25.127 Not all four cylinder engines are alike, of course; 00:03:25.127 --> 00:03:28.875 these cylinders come in many different sizes, so some are more powerful than others, 00:03:29.275 --> 00:03:31.511 and they're not always arranged in a line. 00:03:32.011 --> 00:03:33.479 We'll talk more about that later, though. 00:03:34.480 --> 00:03:36.815 Oh also sometimes there aren't cylinders at all! 00:03:36.815 --> 00:03:40.072 But that's mainly a Mazda thing they only sometimes do 00:03:40.072 --> 00:03:43.957 because rotary engines are equal parts cool and terrible. 00:03:44.390 --> 00:03:45.592 But they're committed to them! 00:03:46.559 --> 00:03:48.228 Sometimes - for special occasions. 00:03:48.661 --> 00:03:51.864 Anyway, the cylinders are each a combustion chamber. 00:03:52.265 --> 00:03:55.602 The idea is to fill these cylinders with a mixture of air and fuel, 00:03:55.602 --> 00:03:57.637 and then ignite that mixture so it... 00:03:58.938 --> 00:04:00.974 expands very rapidly. 00:04:01.274 --> 00:04:03.576 I would say that mixture explodes, 00:04:03.576 --> 00:04:05.645 but it's not technically an explosion. 00:04:06.179 --> 00:04:08.314 What's really happening is that the carbon dioxide 00:04:08.314 --> 00:04:11.050 and water vapor that are produced in the combustion process 00:04:11.284 --> 00:04:15.922 have a much larger volume than the fuel and air did before it ignited, 00:04:16.256 --> 00:04:20.278 and that rapid expansion of hot gases inside the combustion chamber 00:04:20.278 --> 00:04:23.129 can be harnessed and turned into mechanical work. 00:04:23.830 --> 00:04:26.299 And to do that we use pistons. 00:04:26.766 --> 00:04:30.637 Each cylinder gets a piston just like this inserted from the bottom, 00:04:30.903 --> 00:04:35.426 and these pistons are able to slide up and down inside the cylinders. 00:04:35.426 --> 00:04:40.713 During a combustion event, as the mixture of hot gases inside the cylinder rapidly expands 00:04:41.080 --> 00:04:44.317 these pistons are forced downward into the engine block. 00:04:44.684 --> 00:04:49.188 And that's how we convert the chemical energy in the fuel into mechanical energy. 00:04:50.590 --> 00:04:54.127 Now, the goal of this engine is to spin the wheels of a car. 00:04:54.127 --> 00:04:57.397 So ultimately the engine produces rotational movement. 00:04:57.830 --> 00:05:01.167 And since the pistons move up and down inside the cylinders, 00:05:01.534 --> 00:05:06.506 we're going to need a mechanism to translate their up and down motion into a spinning motion. 00:05:07.607 --> 00:05:11.877 If you noticed the weird stick thing with a ring on the end that each piston has, 00:05:11.877 --> 00:05:16.064 well, this is the connecting rod and it's there to connect the pistons 00:05:16.064 --> 00:05:16.949 to this thing. 00:05:17.717 --> 00:05:21.788 This is the crankshaft, and it is the thing that spins. 00:05:22.488 --> 00:05:25.839 The tachometer, the gauge which tells you engine RPM, 00:05:25.839 --> 00:05:30.596 is telling you how quickly this literal thing is spinning inside the engine block. 00:05:31.731 --> 00:05:35.568 Now we're going to look at this closely in a moment to see how the pistons make it spin. 00:05:36.035 --> 00:05:41.240 But first I want to point out that the crankshaft sticks out from the block on both sides. 00:05:41.874 --> 00:05:44.677 That is how we actually make this spinning crankshaft 00:05:44.711 --> 00:05:46.079 do useful things for us. 00:05:47.046 --> 00:05:48.514 Bolted to one side of it 00:05:48.748 --> 00:05:51.818 is this large rusty wheel with teeth on its edges. 00:05:52.385 --> 00:05:54.354 This is what's known as a flexplate. 00:05:54.987 --> 00:05:59.525 The teeth on its circumference are there for the electric starter motor to engage with, 00:06:00.000 --> 00:06:03.963 and turn the crankshaft inside the engine in order to start it from a stop. 00:06:04.764 --> 00:06:08.568 But the rest of this connects the engine to the transmission 00:06:08.768 --> 00:06:10.536 so that once the engine is running 00:06:10.536 --> 00:06:13.272 the spinning crankshaft can spin the wheels of the car. 00:06:14.173 --> 00:06:18.075 Technical note: if you were expecting me to call this a flywheel, 00:06:18.075 --> 00:06:20.472 well, this is not a flywheel. 00:06:20.472 --> 00:06:21.781 It's a flexplate. 00:06:22.515 --> 00:06:23.716 What's the difference? 00:06:23.950 --> 00:06:27.153 Well, flywheels are used with manual transmissions, 00:06:27.420 --> 00:06:30.289 while flexplates are used with automatic transmissions. 00:06:31.023 --> 00:06:34.761 In a car with an automatic, which is what this engine was taken from, 00:06:35.061 --> 00:06:38.698 the flexplate gets fastened to the transmission's torque converter, 00:06:38.765 --> 00:06:41.868 and the engine and transmission are permanently coupled together. 00:06:42.668 --> 00:06:45.071 But flywheels are completely different. 00:06:45.405 --> 00:06:47.473 They're used with manual transmissions 00:06:47.473 --> 00:06:51.587 and are not really fastened to the transmission at all, 00:06:51.587 --> 00:06:57.216 since in a stick shift the engine and transmission are mated with a clutch under the driver's control. 00:06:58.418 --> 00:07:01.788 The clutch sort of presses up against the flywheel 00:07:01.788 --> 00:07:04.891 when engaged to connect the transmission to the engine, 00:07:05.291 --> 00:07:09.262 and it moves away from the flywheel when disengaged to separate them. 00:07:09.695 --> 00:07:12.932 And because of this, flywheels have a smooth surface 00:07:12.932 --> 00:07:15.701 on the outer side which the clutch pushes against. 00:07:16.369 --> 00:07:19.639 It's also quite a lot thicker and heavier than a flexplate 00:07:19.939 --> 00:07:22.608 to give the crankshaft more rotational momentum: 00:07:22.809 --> 00:07:24.911 helpful when getting the car moving from a stop. 00:07:25.845 --> 00:07:28.314 This Nissan Cube has a manual transmission, 00:07:28.314 --> 00:07:32.552 so its engine has a flywheel attached to the crankshaft and not a flexplate, 00:07:32.852 --> 00:07:34.921 but everything else is identical. 00:07:35.788 --> 00:07:40.747 Now, while moving the car is the main thing the spinning crankshaft has to do, 00:07:40.747 --> 00:07:44.931 it also has to do things like generate electricity to keep the car's battery charged. 00:07:45.298 --> 00:07:48.134 And that needs to happen whether the wheels are moving or not. 00:07:48.734 --> 00:07:53.306 Which is why the other end of the crankshaft also sticks out from the engine block. 00:07:53.673 --> 00:07:57.510 But on this side, all we have attached to it is the small pulley. 00:07:58.344 --> 00:08:00.079 This is the crank pulley 00:08:00.313 --> 00:08:03.802 and it provides power for engine accessories such as the alternator, 00:08:03.802 --> 00:08:07.386 air conditioning compressor and water pump via a drive belt. 00:08:08.221 --> 00:08:11.357 The pulley simply bolts on to the end of the crankshaft here... 00:08:12.792 --> 00:08:14.093 with this large bolt. 00:08:14.760 --> 00:08:16.696 Oh, and like in many engines, 00:08:16.696 --> 00:08:19.198 that pulley has some rubber like material in there 00:08:19.198 --> 00:08:21.634 to allow it to function as a harmonic balancer. 00:08:22.001 --> 00:08:23.369 But that's not important right now. 00:08:24.270 --> 00:08:25.638 What is important right now 00:08:25.638 --> 00:08:30.576 is how the uppy downy pistons actually make the spinny spinny crankshaft spin in the first place. 00:08:31.477 --> 00:08:34.547 To explain, I want you to focus on these very shiny 00:08:34.547 --> 00:08:37.950 and perfectly circular surfaces you can find on the crankshaft. 00:08:38.584 --> 00:08:40.052 These are bearings, 00:08:40.486 --> 00:08:42.021 just plain bearings. 00:08:42.889 --> 00:08:46.592 which is a dad joke because they are literally called plain bearings. 00:08:46.826 --> 00:08:49.128 [voiceover] Oooookay editor me popping in 00:08:49.128 --> 00:08:51.163 with some notes on terminology. 00:08:51.731 --> 00:08:53.833 I made the mistake when writing this script 00:08:53.833 --> 00:08:56.569 of letting a technical definition supersede 00:08:56.569 --> 00:08:58.738 the common language most people use. 00:08:59.372 --> 00:09:01.574 These are indeed plain bearings, 00:09:01.574 --> 00:09:05.978 but they belong to a subset of plain bearing known as journal bearings. 00:09:06.312 --> 00:09:08.948 And the circular, shiny things we're looking at on the crankshaft 00:09:08.948 --> 00:09:11.517 are usually referred to as the journals. 00:09:12.585 --> 00:09:14.053 But here's the thing. 00:09:14.554 --> 00:09:17.823 Journal is simply another word for shaft. 00:09:18.291 --> 00:09:21.227 All these things are is a polished, circular shaft 00:09:21.227 --> 00:09:24.030 which spins inside of a stationary circle, 00:09:24.030 --> 00:09:26.365 which wraps around and holds on to the shaft. 00:09:26.933 --> 00:09:30.002 Once put together, it's really just two concentric circles 00:09:30.002 --> 00:09:32.104 where one spins and the other doesn't. 00:09:32.805 --> 00:09:36.008 And both the spinning journal and its stationary 00:09:36.008 --> 00:09:38.778 holder are a bearing surface, 00:09:38.778 --> 00:09:40.947 which is what I wanted to highlight in this video. 00:09:41.447 --> 00:09:44.216 The interface between those two bearing surfaces 00:09:44.216 --> 00:09:46.419 is what really matters to the point here. 00:09:46.786 --> 00:09:49.655 And from either one's individual perspective, 00:09:50.022 --> 00:09:51.857 the other part is what's spinning. 00:09:51.857 --> 00:09:56.095 And so that's why I ultimately chose to refer to these as bearings. 00:09:56.562 --> 00:09:59.498 But I understand a lot of people will be very annoyed by that choice. 00:09:59.498 --> 00:10:01.834 And so... sorry about that. 00:10:02.802 --> 00:10:04.103 They consist of that smooth, 00:10:04.103 --> 00:10:06.305 shiny part in the center of the crankshaft 00:10:06.572 --> 00:10:08.808 and a thin bushing which surrounds it. 00:10:09.075 --> 00:10:11.510 You can see half of the bushings here in the block. 00:10:12.111 --> 00:10:13.346 [voiceover] Oh, hi. Me again. 00:10:13.546 --> 00:10:15.581 See, this right here explains the problem. 00:10:15.915 --> 00:10:17.984 This is literally the bearing. 00:10:17.984 --> 00:10:19.552 This is the bearing surface. 00:10:19.552 --> 00:10:21.554 But technically it is a bushing. 00:10:21.821 --> 00:10:23.789 However, when people rebuild engines, 00:10:23.789 --> 00:10:25.191 they're going to refer to these things 00:10:25.191 --> 00:10:28.160 as the bearing because it's the bearing surface. 00:10:28.661 --> 00:10:31.230 And hopefully that helps explain why I had such decision 00:10:31.230 --> 00:10:33.132 paralysis around the terminology here. 00:10:33.766 --> 00:10:36.669 Five of the bearings are all arranged in a straight line. 00:10:37.003 --> 00:10:38.871 These are the main bearings 00:10:38.871 --> 00:10:42.141 which hold the crankshaft in the block and keep it centered, 00:10:42.942 --> 00:10:47.546 but the remaining four are wildly offset from the rest. 00:10:48.447 --> 00:10:52.184 These eccentric bearings are what the pistons attach to. 00:10:52.818 --> 00:10:55.388 The big round part at the bottom of the connecting rod 00:10:55.388 --> 00:10:58.090 can be split in half by loosening these fasteners. 00:10:58.324 --> 00:11:01.527 And then you can attach the piston and its bushings 00:11:01.727 --> 00:11:03.229 to its respective bearing. 00:11:04.730 --> 00:11:08.267 Now, I want to point out as I very loosely attach this, 00:11:08.534 --> 00:11:12.638 that the mating surfaces here are both metal. 00:11:13.739 --> 00:11:16.909 This is literally metal on metal contact, 00:11:16.909 --> 00:11:20.646 and these components slide against each other as they spin around, 00:11:21.414 --> 00:11:23.349 which feels problematic, doesn't it? 00:11:24.350 --> 00:11:26.018 Keep that in mind as we continue. 00:11:26.886 --> 00:11:30.823 If you're wondering why the crankshaft has these weird lobe things, 00:11:31.223 --> 00:11:33.993 well, remember, this is the thing that spins. 00:11:34.293 --> 00:11:39.732 And since the bearings that the pistons attach to are wildly offset from the center, 00:11:40.232 --> 00:11:42.735 you need counterweights to keep it balanced. 00:11:42.735 --> 00:11:44.003 And that's what these are. 00:11:45.071 --> 00:11:49.809 This is roughly how fast the crankshaft spins when the engine is at idle! 00:11:50.176 --> 00:11:53.813 And at redline, it can be spinning ten times as fast. 00:11:54.380 --> 00:11:56.315 So you really want this thing 00:11:56.315 --> 00:11:59.452 as perfectly balanced as you can possibly get it 00:11:59.618 --> 00:12:02.254 to reduce vibration which could tear the engine apart. 00:12:02.655 --> 00:12:06.492 And you can even see marks where small amounts of material were drilled 00:12:06.492 --> 00:12:10.753 out of the counterweights after casting to make fine adjustments to balance. 00:12:11.497 --> 00:12:13.232 But anyway, back to the pistons. 00:12:13.766 --> 00:12:16.001 Once assembled, the pistons function 00:12:16.001 --> 00:12:18.604 very much like your feet when pedaling a bicycle. 00:12:19.171 --> 00:12:21.340 In fact, if you look at the crankshaft closely, 00:12:21.340 --> 00:12:23.309 you'll see that on each end of it 00:12:23.876 --> 00:12:27.713 is basically the exact same mechanism as the crank arm of a bike. 00:12:28.414 --> 00:12:32.685 And here's what it looks like with all the pistons attached and the crankshaft turning. 00:12:33.819 --> 00:12:37.356 There are several things wrong with this demonstration. 00:12:37.590 --> 00:12:39.258 For instance, this is upside down. 00:12:39.525 --> 00:12:42.161 But you'll notice that as the crankshaft rotates, 00:12:42.161 --> 00:12:45.397 the four pistons move up and down into pairs. 00:12:45.664 --> 00:12:47.199 When the outer two are at the bottom, 00:12:47.199 --> 00:12:49.702 the inner two are at the top and Nissan Versa, 00:12:50.369 --> 00:12:53.806 and they go round and round like a very strange Ferris wheel. 00:12:54.807 --> 00:12:56.442 I mean, there is a lot of iron in there. 00:12:57.176 --> 00:13:01.280 and here's what that looks like with the pistons and crankshaft inside the block 00:13:01.280 --> 00:13:03.382 and the starter motor turning the crankshaft. 00:13:04.283 --> 00:13:07.453 The block constrains the lateral movement of the pistons 00:13:07.620 --> 00:13:10.756 which means the piston needs to be able to pivot back 00:13:10.756 --> 00:13:13.092 and forth with respect to its connecting rod 00:13:13.325 --> 00:13:15.661 as it flies around the crankshaft below. 00:13:16.629 --> 00:13:18.097 That's why the connecting rod 00:13:18.097 --> 00:13:22.902 is attached to the piston with what's called a wrist pin (or gudgeon pin if you're British). 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. 00:13:28.974 --> 00:13:33.546 And that's how the piston can stay on a perfectly vertical track inside the block, 00:13:33.846 --> 00:13:37.116 while its connecting rod is flailing all around below. 00:13:37.983 --> 00:13:39.118 Here's a fun fact! 00:13:39.118 --> 00:13:40.519 While editing this video, 00:13:40.553 --> 00:13:44.490 I discovered that I accidentally deleted this section from the script. 00:13:44.490 --> 00:13:45.925 So here's me putting it back! 00:13:46.592 --> 00:13:49.228 When we are talking about an engine's size, 00:13:49.528 --> 00:13:53.966 we're not actually talking about how large the cylinders in the block are. 00:13:54.733 --> 00:13:56.735 At least not entirely. 00:13:57.503 --> 00:14:00.773 We measure an engine's size by its displacement, 00:14:00.773 --> 00:14:05.277 and that is defined by how much volume the pistons displace 00:14:05.477 --> 00:14:08.180 as they move up and down inside the cylinders. 00:14:08.981 --> 00:14:11.517 The pistons can only move down so far, 00:14:11.717 --> 00:14:13.819 which only opens up so much space. 00:14:14.119 --> 00:14:16.722 And in this engine, each piston moves 00:14:16.722 --> 00:14:20.025 through a volume of 450cm³. 00:14:20.759 --> 00:14:23.596 There are four of them, of course, and added together, 00:14:23.596 --> 00:14:26.599 that means the pistons displace a total volume 00:14:26.799 --> 00:14:31.670 of 1800cm³, or 1.8 liters. 00:14:31.937 --> 00:14:34.974 And that is why this is a 1.8l engine. 00:14:35.708 --> 00:14:39.144 However, we could increase this engine's displacement 00:14:39.144 --> 00:14:41.580 without making the cylinders any bigger at all. 00:14:42.314 --> 00:14:46.218 All we'd need to do is increase the stroke of the pistons 00:14:46.218 --> 00:14:51.891 so that they travel farther down before they start heading back up, and boom, more displacement! 00:14:53.192 --> 00:14:57.529 But that's much easier said than done, because to actually make that happen, 00:14:57.730 --> 00:15:02.001 we'd need an entirely different and much larger crankshaft, 00:15:02.401 --> 00:15:04.403 which will require redesigning the block. 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, 00:15:12.211 --> 00:15:15.614 so it might not be desirable for all applications. 00:15:16.548 --> 00:15:18.250 This is all very complicated, 00:15:18.384 --> 00:15:22.021 but an engine's displacement presents a hard limit 00:15:22.021 --> 00:15:24.523 to how much power it can theoretically produce, 00:15:24.790 --> 00:15:26.759 and this is why, purportedly, 00:15:27.092 --> 00:15:29.361 there is no replacement for displacement. 00:15:30.930 --> 00:15:35.100 Then again, my daily driver has an engine displacement of null, 00:15:35.100 --> 00:15:39.038 and yet it can still do 0 to 60 in well under five seconds. 00:15:39.405 --> 00:15:41.473 So I'm not sure how true that is these days. 00:15:41.473 --> 00:15:42.675 But anyway, let's move on. 00:15:43.108 --> 00:15:47.880 And at this point, we've looked at nearly everything which lives inside the engine block. 00:15:48.781 --> 00:15:51.984 But now you might have noticed a bit of a problem. 00:15:52.851 --> 00:15:55.354 I said that the cylinders are combustion chambers 00:15:55.521 --> 00:15:58.357 and expanding gases pushed the pistons down. 00:15:59.158 --> 00:16:00.993 But, uh, right now 00:16:00.993 --> 00:16:03.228 those gases don't have anything to push against. 00:16:03.629 --> 00:16:05.864 This is just a weird series of cups 00:16:05.864 --> 00:16:08.300 where the bottom can move up and down for some reason. 00:16:09.268 --> 00:16:12.304 To actually turn all these into combustion chambers, 00:16:12.538 --> 00:16:13.739 we need to seal it up. 00:16:14.006 --> 00:16:16.008 And that's done with the cylinder head. 00:16:16.775 --> 00:16:18.877 But also the piston rings. 00:16:19.478 --> 00:16:22.181 Before we even talk about sealing the top of the chamber, 00:16:22.381 --> 00:16:26.285 we also need a seal between the pistons themselves and the walls of the cylinders. 00:16:27.119 --> 00:16:29.288 The pistons are actually slightly smaller 00:16:29.288 --> 00:16:31.757 than the cylinders and can flop around in there a little bit. 00:16:32.024 --> 00:16:35.060 So each one has not one, not two, 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, 00:16:40.866 --> 00:16:42.067 but it doesn't have the same job. 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 00:16:50.109 --> 00:16:54.980 which causes them to expand and fill the gap between the piston and the cylinder walls. 00:16:56.048 --> 00:16:59.418 There are two of them because in order to put the ring on the piston, 00:16:59.885 --> 00:17:04.123 it needs a gap, and that gap means the seal isn't so good. 00:17:04.123 --> 00:17:06.925 So, well, we just throw a second one on there, 00:17:06.925 --> 00:17:09.962 and ideally you'll position the gaps on opposite side - 00:17:10.295 --> 00:17:11.290 Well, that one broke! 00:17:11.290 --> 00:17:14.795 [through laughter] on opposite sides of the piston when putting the thing together. 00:17:15.034 --> 00:17:18.971 So with the pistons now sufficiently sealed against the cylinders, 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. 00:17:24.176 --> 00:17:26.745 And that's what this guy is for. 00:17:27.446 --> 00:17:29.181 This is the cylinder head 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, 00:17:33.845 --> 00:17:38.157 actually seals the cylinders up so they can become combustion chambers. 00:17:38.824 --> 00:17:41.326 But this does far more than just that. 00:17:41.760 --> 00:17:45.264 This is also what allows fresh air and fuel into the cylinders, 00:17:45.397 --> 00:17:47.399 what expels exhaust from the cylinders, 00:17:47.800 --> 00:17:49.968 and what ignites the air/fuel mixture. 00:17:52.638 --> 00:17:55.007 Well, the spark plug is what does that for each cylinder. 00:17:55.007 --> 00:17:56.608 But the spark plugs live in the cylinder head. 00:17:56.975 --> 00:17:58.911 You can, see 'em poking out just there. 00:17:59.611 --> 00:18:04.750 To actually let air and fuel into, as well as exhaust out of, the combustion chambers, 00:18:05.050 --> 00:18:07.286 the cylinder head contains valves. 00:18:07.886 --> 00:18:12.958 Like most modern engines there are four valves per cylinder, two each for intake and exhaust. 00:18:13.759 --> 00:18:15.694 You really only need one of each, 00:18:15.961 --> 00:18:18.764 but geometry makes it so you can have more total area 00:18:18.764 --> 00:18:22.000 if you have two smaller valves rather than one big one, 00:18:22.401 --> 00:18:24.503 and that allows the engine to breathe more easily. 00:18:25.370 --> 00:18:28.173 From this side, the valves look like little circles, 00:18:28.173 --> 00:18:31.577 but what they actually look like is golf tees. 00:18:32.111 --> 00:18:33.245 And I'm totally serious. 00:18:33.245 --> 00:18:35.481 They're basically just large golf tees. 00:18:36.215 --> 00:18:38.750 I'd remove one to show you, but you see, 00:18:38.750 --> 00:18:41.286 they're held shut with extremely powerful springs 00:18:41.286 --> 00:18:43.655 and I do not have the guts to remove them for you. 00:18:45.190 --> 00:18:46.391 So I bought these ones! 00:18:47.059 --> 00:18:49.795 All that each of these little valves is really doing 00:18:50.295 --> 00:18:52.498 is plugging a hole in the cylinder head. 00:18:53.198 --> 00:18:56.702 On the sides of the cylinder head are the intake and exhaust ports. 00:18:57.169 --> 00:19:01.039 These are where air and fuel goes into the engine on one side 00:19:01.206 --> 00:19:03.108 and exhaust comes out of it on the other. 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. 00:19:10.282 --> 00:19:13.218 To keep that hole plugged up and the combustion chamber sealed, 00:19:13.519 --> 00:19:16.255 a spring being held by this retaining mechanism 00:19:16.455 --> 00:19:21.326 is constantly pulling up on the valve stem and keeping it firmly in its seat. 00:19:22.094 --> 00:19:26.064 But if something pushes down hard enough to overcome the force of the spring, 00:19:26.398 --> 00:19:29.001 the valves will poke out from where they sit 00:19:29.268 --> 00:19:31.737 and suddenly the hole isn't plugged any longer. 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. 00:19:37.843 --> 00:19:42.047 We now have all the ingredients to make a series of combustion chambers 00:19:42.247 --> 00:19:45.851 that we can move gases into and out of under our control. 00:19:46.251 --> 00:19:49.955 But what actually opens and closes the valves? 00:19:51.590 --> 00:19:53.559 Well, these things, 00:19:53.792 --> 00:19:55.794 but, more on them in a moment. 00:19:56.028 --> 00:19:59.331 Now, we need to discuss the four stroke engine cycle. 00:20:00.132 --> 00:20:04.198 Virtually every engine out there which isn't a very big diesel engine 00:20:04.198 --> 00:20:05.904 or a very small weed whacker engine, 00:20:05.904 --> 00:20:09.675 or in a very old car is a four stroke engine, 00:20:09.875 --> 00:20:12.544 which means that when looking at a single cylinder, 00:20:12.744 --> 00:20:15.280 the piston actually travels up and down 00:20:15.280 --> 00:20:17.916 two complete times per combustion event. 00:20:18.684 --> 00:20:21.353 First, it travels down during the intake stroke, 00:20:21.353 --> 00:20:26.291 where the intake valve is open and fresh air and fuel is brought into the cylinder. 00:20:27.092 --> 00:20:30.696 Then the valves will close and the piston travels back up 00:20:30.696 --> 00:20:35.634 during the compression stroke, which squeezes that air and fuel into a tiny little space. 00:20:36.368 --> 00:20:37.703 When the piston is at the top, 00:20:37.803 --> 00:20:39.137 the spark plug fires 00:20:39.137 --> 00:20:43.642 which ignites that mixture and forces the piston down during the power stroke, 00:20:43.642 --> 00:20:46.311 which is the only stroke that actually produces motive power. 00:20:47.212 --> 00:20:49.314 And finally, the piston moves back up again 00:20:49.314 --> 00:20:53.018 with the exhaust valve open during the exhaust stroke, 00:20:53.218 --> 00:20:56.488 where the piston will push the exhaust gases out of the cylinder. 00:20:57.356 --> 00:20:58.523 And then that repeats. 00:20:58.523 --> 00:21:01.960 That's intake, compression, power, and exhaust. 00:21:02.427 --> 00:21:03.996 And for a helpful way to remember that, 00:21:03.996 --> 00:21:06.565 which I'm sure many of you out there really want me to say... 00:21:07.566 --> 00:21:09.434 suck, squeeze, bang, blow. 00:21:10.302 --> 00:21:12.971 To make that sequence actually happen though, 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. 00:21:18.844 --> 00:21:23.015 And to make that happen, we use rotating camshafts like this. 00:21:24.116 --> 00:21:28.787 These fellas are held captive with this bracket and spin above the valves. 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, 00:21:35.661 --> 00:21:39.298 it will press down on its respective valve and open it. 00:21:40.098 --> 00:21:41.300 Here's what that looks like. 00:21:42.034 --> 00:21:46.071 I want to point out yet again that this is metal on metal contact, 00:21:46.438 --> 00:21:49.474 but you may notice in this footage that some kind of dark 00:21:49.474 --> 00:21:52.411 liquid appears to be oozing out of various places 00:21:52.644 --> 00:21:54.446 and getting all over the cams. 00:21:55.280 --> 00:21:56.481 That's engine oil. 00:21:57.282 --> 00:21:58.800 Where is it coming from? 00:21:59.418 --> 00:22:00.252 The oil pump. 00:22:00.252 --> 00:22:01.620 But hold on, we're not there yet. 00:22:02.187 --> 00:22:05.957 First, I want to point out that the sequence in which the valves are opened 00:22:06.191 --> 00:22:09.227 is programed by the physical shape of these things, 00:22:09.461 --> 00:22:12.864 and that, along with the crankshaft design, dictates 00:22:12.864 --> 00:22:14.499 the engine's firing order. 00:22:15.534 --> 00:22:18.570 This engine doesn't fire the cylinders in sequence. 00:22:18.704 --> 00:22:23.859 In fact, it skips around a bit with a firing order of 1 - 3 - 4 - 2 00:22:24.576 --> 00:22:27.379 And if I slowly rotate the camshaft, 00:22:27.646 --> 00:22:31.416 you'll see that the lobes stick out in that same order 00:22:31.416 --> 00:22:34.653 because they have to open the valves in that order. 00:22:35.987 --> 00:22:37.856 This engine could have been designed 00:22:37.856 --> 00:22:40.492 with a simple 1 - 2 - 3 - 4 firing order, 00:22:40.759 --> 00:22:43.328 but that would require a different crankshaft 00:22:43.328 --> 00:22:45.897 where pistons one and three are at the top, 00:22:46.098 --> 00:22:48.166 while two and four are at the bottom. 00:22:48.700 --> 00:22:51.169 And when you do that with an inline four cylinder, 00:22:51.670 --> 00:22:55.140 it tends to be even more of a vibrating mess than it already is. 00:22:55.140 --> 00:22:57.275 Which is why the pistons are paired like this 00:22:57.576 --> 00:22:59.878 and the firing order skips around a bit. 00:23:00.412 --> 00:23:01.713 It's just a better balance. 00:23:02.547 --> 00:23:05.183 But now we have a bit of a timing problem. 00:23:05.984 --> 00:23:09.888 We need to make absolutely sure that those valves are opening 00:23:09.888 --> 00:23:14.626 when they should be in relation to the pistons moving inside the engine block. 00:23:15.694 --> 00:23:21.066 One way to do that would be to mechanically interlock the camshafts with the crankshaft, 00:23:21.166 --> 00:23:23.869 which is exactly what this and any engine does, 00:23:24.302 --> 00:23:27.806 but it's a little more complicated than you might imagine at first. 00:23:28.006 --> 00:23:30.575 Recall this is a four stroke engine, 00:23:30.909 --> 00:23:35.814 which means the pistons travel up and down twice for every time a valve opens. 00:23:36.748 --> 00:23:41.720 But since the camshafts only make one rotation to open their valve, 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. 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. 00:23:56.868 --> 00:24:00.439 Luckily, that's easy to do with our old friend gears. 00:24:01.139 --> 00:24:02.808 You may have noticed a couple of gears 00:24:02.808 --> 00:24:05.444 on the end of the crankshaft away from the flex plate. 00:24:06.111 --> 00:24:10.649 This smaller gear will drive the camshafts with the help of a chain. 00:24:11.650 --> 00:24:13.785 That's this guy, the timing chain, 00:24:14.119 --> 00:24:17.155 and it lives underneath this cover on the side of the engine. 00:24:17.889 --> 00:24:21.793 Its job is to transmit motion from the crankshaft at the bottom 00:24:22.194 --> 00:24:24.729 all the way up to the camshafts at the top. 00:24:25.964 --> 00:24:29.534 Now the chain is going to keep them mechanically locked together, 00:24:29.868 --> 00:24:35.073 but importantly, the crankshaft's gear has exactly half as many teeth 00:24:35.273 --> 00:24:37.509 as the gears which drive the camshafts. 00:24:38.109 --> 00:24:40.479 There are 23 teeth on the crankshaft gear 00:24:40.679 --> 00:24:43.482 and 46 on both of these camshaft gears, 00:24:44.049 --> 00:24:49.087 and that ratio will ensure it always takes exactly two rotations of the crankshaft 00:24:49.354 --> 00:24:52.390 for the camshaft to make a single rotation. 00:24:52.991 --> 00:24:54.793 And so long as this chain doesn't break, 00:24:55.093 --> 00:24:57.562 they will remain perfectly locked together 00:24:57.562 --> 00:25:00.565 such that the valves always open at the same time 00:25:00.765 --> 00:25:03.435 in relation to the pistons inside the engine block. 00:25:04.503 --> 00:25:08.240 Of course, we can actually fiddle with that while the engine is running, 00:25:08.240 --> 00:25:10.408 and that's why this gear is so thick. 00:25:10.408 --> 00:25:12.444 But we are not getting into that today! 00:25:13.245 --> 00:25:17.282 At this point, I've covered all the mechanical basics of this engine. 00:25:17.649 --> 00:25:20.252 And while this is a very common design, 00:25:20.552 --> 00:25:22.320 it's by no means universal. 00:25:22.954 --> 00:25:25.657 For one thing, lots of engines have more than 00:25:25.657 --> 00:25:27.792 or even less than four cylinders. 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. 00:25:33.765 --> 00:25:36.968 And of course, there's all those V6es and V8s 00:25:37.736 --> 00:25:39.571 V engines are interesting 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. 00:25:47.412 --> 00:25:51.516 This makes them only marginally larger than their inline counterparts, 00:25:51.683 --> 00:25:55.520 while doubling the number of cylinders, and thus the power it can produce. 00:25:56.421 --> 00:26:00.425 But more cylinders means a thirstier engine which costs more to operate, 00:26:00.792 --> 00:26:03.361 which is why the old four banger is so dang common. 00:26:04.563 --> 00:26:05.764 It's good enough. 00:26:06.364 --> 00:26:10.068 but even within inline fours, there's a ton of variation. 00:26:10.769 --> 00:26:15.574 This engine has separate camshafts for the intake valves and the exhaust valves, 00:26:15.874 --> 00:26:18.810 and where these live is above the cylinder head. 00:26:19.144 --> 00:26:22.347 And that makes this a dual overhead cam engine. 00:26:23.148 --> 00:26:25.917 If you've ever seen DOHC on an engine cover 00:26:25.917 --> 00:26:28.386 or like on the side of an old car as a badge, 00:26:28.954 --> 00:26:32.023 that is literally referring to these two cams 00:26:32.023 --> 00:26:34.893 and where they are in relation to the rest of the engine. 00:26:35.894 --> 00:26:38.797 Some engines only use one camshaft, 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. 00:26:44.636 --> 00:26:47.405 And that would be a single overhead cam engine, 00:26:47.439 --> 00:26:48.640 SOHC. 00:26:49.174 --> 00:26:51.910 But the camshaft isn't always over the heads. 00:26:51.910 --> 00:26:53.878 Sometimes it lives in the block. 00:26:54.613 --> 00:26:57.115 Many of those engines will use push rods, 00:26:57.115 --> 00:27:00.418 basically metal sticks which ride on the cams, 00:27:00.719 --> 00:27:03.922 and then they stick up into the head so that as the cams 00:27:04.089 --> 00:27:06.558 rotate and the lobe pushes up on the stick, 00:27:06.925 --> 00:27:09.961 the push rod will actuate itself against a rocker arm, 00:27:09.961 --> 00:27:11.863 which then pushes down on the valves. 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. 00:27:18.837 --> 00:27:22.507 Oh, and not every engine will use a timing chain. 00:27:23.241 --> 00:27:28.180 For some reason we decided to start using timing belts made of rubber. 00:27:29.347 --> 00:27:31.149 Okay, the reason was 00:27:31.149 --> 00:27:33.151 that it made engines a little quieter 00:27:33.251 --> 00:27:34.953 and it's not completely without merit. 00:27:34.953 --> 00:27:39.491 But don't get me started on Ford's wet timing belt situation. 00:27:39.791 --> 00:27:43.695 Just an utterly terrible idea they should be shamed for forever! 00:27:44.596 --> 00:27:49.632 Regardless, engines with timing belts need regular replacement of that belt, 00:27:49.632 --> 00:27:53.138 because many engines are what's called an interference engine, 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 00:27:58.943 --> 00:28:00.945 that the pistons do when they're at the top. 00:28:01.746 --> 00:28:03.815 So long as the engine is in time, 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. 00:28:07.552 --> 00:28:10.221 But if the timing belt were to break 00:28:10.221 --> 00:28:15.126 and the cams stop turning with a valve open and sticking down into the cylinder, 00:28:15.794 --> 00:28:21.499 then as the crankshaft keeps on rotating, its respective piston will slam into that stuck valve 00:28:21.866 --> 00:28:24.536 and cause lots of very expensive damage. 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. 00:28:31.076 --> 00:28:36.981 Timing chains are much, much less likely to break, but they can fail. 00:28:37.382 --> 00:28:39.551 Usually, though, it's not catastrophic. 00:28:39.884 --> 00:28:44.740 Instead, they simply start to stretch out a bit due to the links wearing down, 00:28:44.740 --> 00:28:49.360 which makes valve timing sloppy, but not necessarily bad enough to be a problem. 00:28:50.195 --> 00:28:54.199 Though if it does get bad enough to where the chain skips a tooth, 00:28:54.833 --> 00:28:58.737 replacing a timing chain is a lot more involved than a belt, 00:28:58.737 --> 00:29:00.705 so there is that to consider. 00:29:02.040 --> 00:29:05.443 Right, and some pushrod engines don't use a belt or a chain. 00:29:05.844 --> 00:29:08.446 If the camshaft is close enough to the crankshaft, 00:29:08.446 --> 00:29:10.882 you can simply use interlocking gears. 00:29:11.516 --> 00:29:15.420 But again, pushrod engines in cars are pretty much a relic of the past, 00:29:15.420 --> 00:29:17.021 with some notable exceptions. 00:29:17.889 --> 00:29:21.292 Oh, and also there's flathead engines where the valves aren't even in the heads. 00:29:21.292 --> 00:29:25.230 But those are very old designs, and this rabbit hole is very, very deep. 00:29:25.230 --> 00:29:26.765 And eventually you just have to stop. 00:29:27.532 --> 00:29:28.733 Speaking of stop... 00:29:28.933 --> 00:29:30.535 At this point, you're probably wondering 00:29:30.535 --> 00:29:32.437 how any of this relates to the intro 00:29:32.437 --> 00:29:35.373 and the thing about that little red light with a picture of an oiling can. 00:29:36.574 --> 00:29:40.411 Well, everything we've been talking about is made of metal. 00:29:41.112 --> 00:29:45.683 There's metal on metal contact everywhere inside this engine, 00:29:45.683 --> 00:29:49.420 and those bits of metal spin really, really fast. 00:29:50.021 --> 00:29:51.623 Or in the case of the pistons, 00:29:52.056 --> 00:29:55.760 those bits of metal slide against each other really, really fast. 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. 00:30:03.368 --> 00:30:05.603 And that is what engine oil is for. 00:30:06.371 --> 00:30:10.475 Hanging off the bottom of the engine block is what's called the oil pan. 00:30:10.708 --> 00:30:12.844 And this is effectively just a big bucket 00:30:12.944 --> 00:30:15.513 which holds several quarts of motor oil. 00:30:16.414 --> 00:30:18.750 Well, this engine has a weird design 00:30:18.750 --> 00:30:21.019 and the block is split into two pieces. 00:30:21.019 --> 00:30:23.922 So it doesn't really have an oil pan per se, 00:30:23.922 --> 00:30:25.623 but the gist is the same. 00:30:26.124 --> 00:30:29.394 This bottom half of the block alongside a plate, 00:30:29.394 --> 00:30:32.556 which is the closest thing to an oil pan this engine has, 00:30:32.556 --> 00:30:35.099 holds just about four liters of oil. 00:30:35.767 --> 00:30:40.805 Apparently its precise oil capacity is four and 3/8 of a US quart. 00:30:41.639 --> 00:30:45.210 And sitting below the crankshaft inside the oil pan 00:30:46.311 --> 00:30:48.213 is this thing: the oil pump. 00:30:48.980 --> 00:30:52.183 every engine which isn't a tiny little thing for like a lawnmower, 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. 00:30:58.156 --> 00:31:02.060 So long as the crankshaft is spinning, the oil pump will be too. 00:31:02.327 --> 00:31:06.931 And what this does is suck engine oil out of this pan with this pickup tube, 00:31:07.131 --> 00:31:09.968 force it through a filter to catch any contaminants, 00:31:09.968 --> 00:31:12.570 and from there, the oil gets sent through many, 00:31:12.837 --> 00:31:16.541 many tiny little holes and passageways throughout the engine. 00:31:17.475 --> 00:31:20.979 Look closely at practically any part of an engine which moves, 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. 00:31:28.152 --> 00:31:30.788 There are so many holes because when an engine is running, 00:31:31.089 --> 00:31:34.811 oil is getting forcefully sprayed all over the dang place. 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, 00:31:40.510 --> 00:31:45.203 well, some of these deliver oil under pressure from the block and into the cylinder head 00:31:45.203 --> 00:31:48.039 so that it can lubricate the bearings of the camshafts 00:31:48.172 --> 00:31:51.276 as well as the cam lobes as they slide along the valves. 00:31:51.910 --> 00:31:55.046 That's why there's oil oozing out of different places in this footage. 00:31:55.847 --> 00:31:57.548 Some of the other holes in this head gasket 00:31:57.548 --> 00:32:01.019 allow that oil to return to the oil pan with the help of gravity, 00:32:01.419 --> 00:32:03.655 though other holes are for engine coolant, 00:32:03.988 --> 00:32:05.623 which we won't be talking about today. 00:32:06.624 --> 00:32:10.595 Regardless, let's take a close look at the block and crankshaft bearings 00:32:10.595 --> 00:32:13.464 because they reveal how this works the best. 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. 00:32:18.703 --> 00:32:20.505 Once it finds its way in the block, 00:32:20.505 --> 00:32:23.708 the oil flows through a series of tubes, 00:32:23.708 --> 00:32:26.244 and you can sort of make out the shape of these tubes 00:32:26.244 --> 00:32:28.780 and how it tees off here in both directions 00:32:28.780 --> 00:32:31.149 by looking at the casting of the block. 00:32:32.150 --> 00:32:35.019 If we look at the main bearing surfaces in the block, 00:32:35.253 --> 00:32:38.122 we'll see that there's a hole in each one of its bushings. 00:32:38.790 --> 00:32:42.226 If I remove the bushing, we'll find another larger hole behind it. 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, 00:32:49.467 --> 00:32:51.569 and that creates a fluid bearing. 00:32:52.337 --> 00:32:56.908 Once there's oil pressure, the metal surfaces aren't actually touching each other. 00:32:57.041 --> 00:33:01.579 Instead, they glide past each other with a thin film of oil between them. 00:33:02.480 --> 00:33:05.516 That's how the bearings allow the engine to spin smoothly 00:33:05.817 --> 00:33:08.586 despite the fact that they're literally just two pieces of metal. 00:33:09.554 --> 00:33:13.391 But you'll notice that there's a channel or groove cut into the bushing here. 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 00:33:19.230 --> 00:33:21.399 and into the crankshaft itself. 00:33:22.333 --> 00:33:24.836 Notice that the bearing also has a hole. 00:33:25.503 --> 00:33:28.373 That hole will move around as the engine spins, 00:33:28.673 --> 00:33:30.975 but it will always be above that groove 00:33:30.975 --> 00:33:33.878 and so will always be fed oil from the block. 00:33:34.645 --> 00:33:37.148 And here we can actually see where the hole leads: 00:33:37.615 --> 00:33:42.186 another hole on another bearing; the bearing that the connecting rod attaches to. 00:33:42.954 --> 00:33:46.457 This is so that those bearings also get lots of lubrication 00:33:46.657 --> 00:33:49.694 and we get that fluid bearing effect which keeps the metals from touching. 00:33:50.461 --> 00:33:52.864 Which by the way in case it's not clear 00:33:52.864 --> 00:33:57.435 oil is only under pressure inside all those passageways and ports and stuff. 00:33:58.202 --> 00:34:00.338 There's a whole bunch more of them too which I haven't covered 00:34:00.338 --> 00:34:03.341 inside the cylinder head to keep the camshafts lubricated 00:34:03.541 --> 00:34:05.410 as well as the moving parts of the valves. 00:34:06.044 --> 00:34:08.446 But once the oil makes its way out of whatever 00:34:08.446 --> 00:34:10.481 confined space it used to be in, 00:34:10.848 --> 00:34:12.950 it will just sort of ooze out. 00:34:12.950 --> 00:34:15.720 And then it's got to get back to the bottom of the engine 00:34:15.720 --> 00:34:17.655 so the oil pump can suck it up again. 00:34:18.256 --> 00:34:21.092 So there is also a series of pathways throughout the engine 00:34:21.092 --> 00:34:25.263 that will simply return any pooling oil to the bottom via gravity. 00:34:25.863 --> 00:34:30.435 And that's why internal combustion engines need to be close to upright to operate. 00:34:31.069 --> 00:34:34.138 If I were to turn this engine upside down and try and operate it, 00:34:34.605 --> 00:34:36.707 or frankly, even on its side like it is now, 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. 00:34:41.879 --> 00:34:43.714 And so the lubrication system just... 00:34:44.916 --> 00:34:46.117 wouldn't work. 00:34:46.617 --> 00:34:52.623 And that's bad because everything inside this engine moves stupidly fast. 00:34:53.191 --> 00:34:57.195 If for whatever reason, the engine were to lose oil pressure, 00:34:57.862 --> 00:35:00.431 then suddenly you have a very big problem. 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 00:35:05.692 --> 00:35:12.243 will go away and now... metal parts are rubbing against each other very quickly, 00:35:12.677 --> 00:35:14.779 and that's going to produce a lot of friction, 00:35:14.779 --> 00:35:16.280 which will produce a lot of heat. 00:35:16.681 --> 00:35:19.083 And before long the engine will seize, 00:35:19.283 --> 00:35:23.654 meaning parts get fuzed together and it can no longer spin at all. 00:35:24.822 --> 00:35:27.692 It is possible to get a seized engine unstuck, 00:35:28.059 --> 00:35:30.561 but it will definitely be damaged in some way 00:35:30.561 --> 00:35:33.264 and will likely have a greatly shortened lifespan. 00:35:33.598 --> 00:35:37.540 So you never, ever, ever, ever want to run an engine 00:35:37.540 --> 00:35:41.839 without knowing that there is sufficient oil pressure to keep that from happening. 00:35:42.773 --> 00:35:45.076 And that is what that light is for. 00:35:45.643 --> 00:35:50.014 It's connected to a pressure switch which in its resting state is closed. 00:35:50.615 --> 00:35:53.084 In other words, when there is no oil pressure, 00:35:53.384 --> 00:35:56.354 that switch completes a circuit which lights up that light. 00:35:57.388 --> 00:35:59.123 This is what the pressure switch looks like. 00:35:59.690 --> 00:36:01.159 It's an unassuming little thing. 00:36:01.893 --> 00:36:03.361 Once the engine is turning, 00:36:03.361 --> 00:36:06.831 the oil pump will start forcing oil into all those passageways. 00:36:07.098 --> 00:36:11.235 And this port on the side is tapped off of those passages. 00:36:11.903 --> 00:36:17.141 So sufficient oil pressure will open this pressure switch and extinguish the warning light. 00:36:17.909 --> 00:36:21.479 This design allows you to check that the pressure switch is actually functional, 00:36:21.879 --> 00:36:24.715 because if you simply turn the key without cranking the engine, 00:36:25.049 --> 00:36:26.918 you should see the oil pressure light. 00:36:27.552 --> 00:36:29.787 There's no oil pressure yet because the engine isn't running! 00:36:30.555 --> 00:36:32.423 But when you start the engine, 00:36:32.590 --> 00:36:35.059 that light should go out almost immediately. 00:36:35.560 --> 00:36:38.129 And if it doesn't, there's a problem. 00:36:38.963 --> 00:36:42.066 That problem isn't necessarily with the engine, of course. 00:36:42.066 --> 00:36:44.402 It could simply be a bad pressure switch. 00:36:45.236 --> 00:36:48.206 But that's a really risky assumption to make 00:36:48.472 --> 00:36:51.842 because if that light and the switch is working as it should, 00:36:52.510 --> 00:36:55.313 then if the light comes on, you are 00:36:55.313 --> 00:36:59.217 then running your engine without oil pressure, which will kill it. 00:37:00.017 --> 00:37:03.988 Oh, and fun fact eagle-eyed viewers of the catalytic converter video 00:37:04.021 --> 00:37:07.692 may have noticed that this car had a bad pressure switch, 00:37:07.959 --> 00:37:09.260 but it failed open. 00:37:09.927 --> 00:37:11.963 The oil pressure light was never coming on 00:37:11.963 --> 00:37:13.431 even without the engine running. 00:37:13.931 --> 00:37:17.368 Here's me turning the key and that light is nowhere to be seen. 00:37:18.236 --> 00:37:21.939 This meant the car could never warn me that I've lost oil pressure, 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. 00:37:27.411 --> 00:37:30.915 Luckily, I happened to buy this entire engine for making videos 00:37:30.915 --> 00:37:32.883 and it had its own oil pressure switch on there, 00:37:33.317 --> 00:37:34.619 so I just swapped them over. 00:37:34.619 --> 00:37:36.821 And now that light is actually doing its job. 00:37:37.822 --> 00:37:38.589 Quick side note, 00:37:38.589 --> 00:37:41.993 a lot of older cars didn't have an oil pressure warning light 00:37:41.993 --> 00:37:44.262 and instead had an oil pressure gauge, 00:37:44.762 --> 00:37:48.933 but that's mostly gone, much to the chagrin of John Davis of MotorWeek. 00:37:49.734 --> 00:37:52.069 Some new vehicles still have oil pressure gauges, 00:37:52.069 --> 00:37:54.672 but they're mainly found in big trucks 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. 00:38:01.012 --> 00:38:05.249 But I mean, most people don't really care 00:38:05.249 --> 00:38:08.552 how much oil pressure an engine is producing at any given moment. 00:38:08.552 --> 00:38:11.289 And without knowledge of how much is actually correct, 00:38:11.656 --> 00:38:13.724 a gauge isn't that useful anyway, 00:38:13.724 --> 00:38:17.161 and that's why a simple pressure switch and warning light which indicates 00:38:17.428 --> 00:38:21.332 "oil pressure is below a safe threshold," is frankly better. 00:38:22.333 --> 00:38:23.534 Yeah, I said it. 00:38:24.035 --> 00:38:26.370 Gearheads like to call these idiot lights 00:38:26.370 --> 00:38:30.641 because we used to expect people to know they should be checking the gauges frequently. 00:38:31.008 --> 00:38:34.011 In fact, some cars in the past had a little yellow warning light 00:38:34.011 --> 00:38:36.113 which literally said "check gauges." 00:38:37.048 --> 00:38:40.851 But while I too lament the loss of drivers being expected to know 00:38:41.052 --> 00:38:44.522 a little more about how their cars work than they seem to now, 00:38:44.989 --> 00:38:48.225 I think it's fair to say a warning light is all that's really needed, 00:38:48.225 --> 00:38:51.462 but you do need to know what that warning light means. 00:38:52.396 --> 00:38:56.100 On that note, why might you actually lose oil pressure? 00:38:57.234 --> 00:39:01.472 Well, it's very rare for it to suddenly just happen. 00:39:02.139 --> 00:39:04.175 I hope I haven't made it sound like this is something 00:39:04.175 --> 00:39:06.949 you need to be extremely vigilant about all the time, 00:39:06.949 --> 00:39:12.283 though you probably should watch the oil pressure light closely after you get an oil change, 00:39:12.316 --> 00:39:13.951 and I'll explain that further in a moment. 00:39:14.952 --> 00:39:17.088 If you're just driving around on a normal day, though, 00:39:17.521 --> 00:39:21.692 it's extremely unlikely that your engine will suddenly lose oil pressure. 00:39:22.393 --> 00:39:26.030 That would really only happen if the oil pump were to somehow fail. 00:39:26.230 --> 00:39:30.534 And given that it's literally the most lubricated part in the whole engine 00:39:30.534 --> 00:39:32.870 since it sits in oil and pumps it around, 00:39:33.571 --> 00:39:34.772 that's quite rare. 00:39:35.373 --> 00:39:37.975 It does happen, but it's extremely rare. 00:39:38.843 --> 00:39:41.645 However, if your engine burns oil, 00:39:41.979 --> 00:39:44.548 which it shouldn't, but it tends to start happening 00:39:44.548 --> 00:39:47.051 when an engine gets very old and worn out. 00:39:47.618 --> 00:39:49.754 Or if it wasn't designed very well, 00:39:50.121 --> 00:39:56.527 well then the amount of oil inside your engine slowly drops as you use your car. 00:39:57.528 --> 00:39:59.894 There's quite a good deal of margin for error, 00:39:59.894 --> 00:40:04.234 so losing a quart of oil between oil changes is not likely to cause a problem. 00:40:04.535 --> 00:40:07.671 But if your engine burns through a lot of oil, 00:40:08.072 --> 00:40:11.008 then eventually the oil level can get low enough 00:40:11.008 --> 00:40:15.312 that the oil pump starts to have trouble sucking any up through the intake tube. 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. 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. 00:40:28.692 --> 00:40:32.696 The bearings inside the engine aren't always getting good oil flow, 00:40:32.963 --> 00:40:35.966 and they're going to start wearing out a lot faster than they should. 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. 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. 00:40:49.780 --> 00:40:52.249 For example, you went in to get an oil change 00:40:52.249 --> 00:40:54.785 and the technician forgot to actually fill the engine 00:40:54.785 --> 00:40:57.555 with new oil after they drained the old oil out. 00:40:57.955 --> 00:41:00.024 Or maybe they forgot to put the drain plug back. 00:41:00.224 --> 00:41:01.892 Or perhaps they didn't tighten it enough 00:41:01.892 --> 00:41:04.028 and it backed itself out as you were driving 00:41:04.328 --> 00:41:06.964 and your car puked all of its oil onto the ground. 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. 00:41:10.901 --> 00:41:13.637 But seriously, after you get an oil change, 00:41:13.637 --> 00:41:15.639 pay attention to that light for a while. 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. 00:41:22.146 --> 00:41:23.414 But speaking of oil changes, 00:41:23.581 --> 00:41:25.749 this car is due for one, so let's do it! 00:41:26.050 --> 00:41:27.251 Why not? 00:41:27.952 --> 00:41:30.654 In fact, I have no idea whether it's actually due for one. 00:41:30.654 --> 00:41:32.990 But that's kind of why I'm doing it. 00:41:33.691 --> 00:41:36.660 Changing your own oil is actually quite easy, 00:41:36.660 --> 00:41:40.164 but I don't really recommend it because it's messy, 00:41:40.364 --> 00:41:42.165 you have to deal with the old oil 00:41:42.165 --> 00:41:45.636 (and yes, parts stores will take used oil for free, but it's still annoying), 00:41:46.136 --> 00:41:49.707 And, it honestly hardly saves any money. 00:41:49.707 --> 00:41:51.809 But why don't I show you the process? 00:41:52.543 --> 00:41:56.714 Actually, first, if you don't know why you have to change the oil 00:41:56.714 --> 00:42:00.184 every some thousand miles or so, well, here's why: 00:42:00.784 --> 00:42:02.319 The oil gets really hot 00:42:02.620 --> 00:42:04.688 and the piston rings aren't perfect. 00:42:05.556 --> 00:42:09.026 Remember, there's a whole bunch of explosions going on in here! 00:42:09.260 --> 00:42:11.896 Several every second, just at idle! 00:42:12.429 --> 00:42:15.980 And the intense pressure inside the cylinders means 00:42:15.980 --> 00:42:20.037 some combustion byproducts are going to end up getting past the piston rings 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. 00:42:26.010 --> 00:42:29.079 That will eventually start to chemically break it down. 00:42:29.847 --> 00:42:31.248 And if that's not bad enough, 00:42:31.248 --> 00:42:35.019 the oil which clings to the cylinder walls gets extremely hot, 00:42:35.019 --> 00:42:37.939 which also causes chemical breakdown. 00:42:37.939 --> 00:42:41.759 Over time, this causes the oil to lose its lubricative properties, 00:42:42.293 --> 00:42:44.495 and that means your engine can start to wear. 00:42:45.329 --> 00:42:47.831 And if you're really overdue for an oil change, 00:42:48.065 --> 00:42:50.401 little bits of stuff can precipitate out 00:42:50.401 --> 00:42:53.237 of old engine oil and stick to things. 00:42:53.604 --> 00:42:55.105 That's engine sludge. 00:42:55.105 --> 00:42:58.275 And if it gets bad enough, it can start breaking things 00:42:58.275 --> 00:43:00.844 by plugging up those tiny oil passageways. 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. 00:43:08.018 --> 00:43:13.357 I'm deliberately not commenting on how often you should do that because nobody agrees. 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. 00:43:21.065 --> 00:43:25.035 But I've got one of those electric cars and it doesn't need oil changes. 00:43:25.336 --> 00:43:26.537 How about that? 00:43:26.704 --> 00:43:28.105 But this one does. 00:43:28.339 --> 00:43:30.741 So first I'll get it up in the air a little bit. 00:43:31.542 --> 00:43:33.611 You don't need a lift to do this. 00:43:33.777 --> 00:43:35.946 If all you want to do is your own oil changes, 00:43:35.946 --> 00:43:39.650 you can purchase these ramps and drive the front of your car onto them, 00:43:39.650 --> 00:43:41.485 and that'll give you enough room to work with. 00:43:42.086 --> 00:43:44.755 There's two things you need access to from the bottom: 00:43:45.022 --> 00:43:47.157 the drain plug and the oil filter. 00:43:47.558 --> 00:43:50.194 Though in some cars the oil filter is somewhere else 00:43:50.194 --> 00:43:52.429 or possibly behind a cover of some sort. 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. 00:43:58.602 --> 00:44:01.805 And then of course, you'll need new oil and a replacement filter. 00:44:02.506 --> 00:44:06.180 Here's a five quart bottle of the cheapest oil I found in the store, 00:44:06.180 --> 00:44:08.874 because this car is not worth getting fancy over, 00:44:08.874 --> 00:44:11.548 and here's a replacement filter which fits the car. 00:44:12.483 --> 00:44:13.617 Speaking of the oil, 00:44:13.617 --> 00:44:17.588 your car's engine is going to call for a specific oil viscosity, 00:44:17.588 --> 00:44:19.757 which some people refer to as its weight. 00:44:20.591 --> 00:44:25.062 The Society of Automotive Engineers came up with a way to define motor oil viscosity 00:44:25.095 --> 00:44:28.999 using a simple numbering scheme, and bigger numbers are more viscous. 00:44:29.933 --> 00:44:32.703 This car needs 5W-30 motor oil. 00:44:33.037 --> 00:44:34.471 And the cool thing about that 00:44:34.638 --> 00:44:38.375 is that this oil has two different viscosity grades. 00:44:38.942 --> 00:44:43.113 When the oil is cold, it has the same viscosity as a five weight oil. 00:44:43.681 --> 00:44:47.051 That's the 5W, and the W is for winter. 00:44:47.718 --> 00:44:49.286 But when the oil is hot 00:44:49.653 --> 00:44:52.356 it has the viscosity of a 30 weight oil. 00:44:53.590 --> 00:44:57.561 Now any oil loses viscosity and gets thinner as it gets hotter. 00:44:57.561 --> 00:44:58.762 And this is no different. 00:44:58.929 --> 00:45:02.700 But as the engine warms up, additives in this formulation 00:45:02.700 --> 00:45:04.968 slow down that thinning process. 00:45:05.269 --> 00:45:08.806 And that's how when it's hot, it has the same viscosity 00:45:08.806 --> 00:45:11.141 as an unmodified 30 weight oil. 00:45:11.909 --> 00:45:14.712 This is actually a really neat thing we figured out how to do. 00:45:14.878 --> 00:45:18.415 And it means the engine has an easier time starting when it's cold, 00:45:18.682 --> 00:45:22.619 but still has the same protection as a 30 weight oil once it's warmed up. 00:45:23.754 --> 00:45:26.724 Right. And the breakdown of those additives over time 00:45:26.724 --> 00:45:32.463 as the oil gets contaminated with combustion byproducts and whatnot, lowers the oil's viscosity grade. 00:45:32.730 --> 00:45:35.566 And that's yet another reason you need to change it periodically. 00:45:36.433 --> 00:45:40.437 So to do that, I'll start by draining the old oil from the engine. 00:45:40.871 --> 00:45:43.607 But first I'm going to remove the filler cap up top, 00:45:43.774 --> 00:45:46.410 which will allow that oil to leave the engine more quickly 00:45:46.410 --> 00:45:49.613 by breaking the vacuum and letting air into the top of the engine. 00:45:50.581 --> 00:45:54.318 Then I'll put the drain pan below the drain plug of the engine, 00:45:54.318 --> 00:45:56.220 but I'm going to position it off-center. 00:45:56.820 --> 00:45:58.155 You'll see why shortly. 00:45:58.956 --> 00:46:02.059 Quick note, the transmission will also have a drain plug, 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. 00:46:07.564 --> 00:46:11.001 Next, I'll use a wrench to crack the drain plug loose. 00:46:11.201 --> 00:46:14.946 The engine is warmed up, by the way, to make the oil flow more easily. 00:46:14.946 --> 00:46:17.942 with a gloved hand I'll then remove the plug. 00:46:18.609 --> 00:46:21.245 If you keep pressing in on it while you back it out, 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, 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. 00:46:31.355 --> 00:46:32.990 And now that it's flowing out of there, 00:46:33.457 --> 00:46:35.926 you can see why I didn't center the drain pan. 00:46:36.894 --> 00:46:40.297 As the old oil flows out, we'll deal with the oil filter. 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. 00:46:47.004 --> 00:46:49.072 Or in the case of this car, 00:46:49.106 --> 00:46:53.110 whatever you call this part, which isn't really the block, but kind of is. 00:46:53.610 --> 00:46:57.481 Anyway, these should only be put on hand tight, 00:46:57.481 --> 00:47:00.184 which means they should come off easily, 00:47:00.350 --> 00:47:03.687 but should is carrying a lot of weight there. 00:47:03.987 --> 00:47:06.423 And that's why I have this oil filter wrench. 00:47:07.157 --> 00:47:09.293 Once it starts coming loose, keep in mind 00:47:09.293 --> 00:47:12.129 this thing is filled with oil and will be gross. 00:47:12.663 --> 00:47:15.098 Many drain pans like this one have a spot 00:47:15.098 --> 00:47:18.035 molded into them to put the used filter and let it drain out. 00:47:18.702 --> 00:47:22.306 And now I'll take the new filter and with my gloved hand, 00:47:22.506 --> 00:47:26.243 I'll smear just a little bit of the old oil onto the gasket 00:47:26.376 --> 00:47:28.245 before screwing it onto the engine. 00:47:28.979 --> 00:47:32.683 And again, this should only go on hand tight. 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. 00:47:38.555 --> 00:47:41.225 But these are like five bucks, so you might as well just change it. 00:47:41.625 --> 00:47:45.796 Its job is to trap things like metal shavings and keep them in the filter 00:47:45.896 --> 00:47:48.198 before they plug up all those little parts and stuff, 00:47:48.198 --> 00:47:49.466 which would be very bad. 00:47:49.466 --> 00:47:51.668 So I don't think it's worth risking it. 00:47:51.668 --> 00:47:52.870 Just replace it. 00:47:53.403 --> 00:47:58.508 By this point, the engine is probably almost done draining the old oil out of itself. 00:47:58.809 --> 00:48:02.179 But if for some reason it's still flowing, let it flow. 00:48:02.913 --> 00:48:06.617 Once it's down to barely a trickle, though you can put the drain plug back. 00:48:07.184 --> 00:48:10.921 Ideally, you'd replace this crush washer which seals that hole, 00:48:11.355 --> 00:48:14.825 but I did not get a replacement, so I will be reusing the old one 00:48:15.692 --> 00:48:17.895 Once I've started threading the plug by hand, 00:48:18.028 --> 00:48:19.696 I'll then reach for an impact wrench. 00:48:20.397 --> 00:48:21.598 Except I'm joking. 00:48:21.632 --> 00:48:24.201 Don't ever use power tools for this. 00:48:24.568 --> 00:48:26.937 If you screw up the threads on the oil pan, 00:48:26.937 --> 00:48:30.674 this oil change went from an easy job to a very bad day. 00:48:30.908 --> 00:48:35.145 So only use hand tools when dealing with drain plugs. 00:48:35.646 --> 00:48:37.814 I even looked up the torque spec for this guy. 00:48:37.948 --> 00:48:41.652 It's 34.3 Newton meters or 25 pound feet. 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, 00:48:46.470 --> 00:48:46.970 but hey. 00:48:47.124 --> 00:48:48.507 It's the thought that counts. 00:48:48.507 --> 00:48:49.459 [click] 00:48:50.327 --> 00:48:51.995 And now we're done down here. 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! 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 00:49:01.972 --> 00:49:04.207 this one made when getting some of this footage, 00:49:04.775 --> 00:49:07.444 but it's definitely not enough for it to run without damage. 00:49:07.778 --> 00:49:10.013 If I were to start it now, that would be very bad. 00:49:10.480 --> 00:49:13.350 Oh, fun fact, did you know engines are dishwasher safe? 00:49:13.984 --> 00:49:16.620 The dishwasher would not agree, but, uh, 00:49:16.620 --> 00:49:18.153 it did clean it. 00:49:18.153 --> 00:49:18.989 Anyway, 00:49:19.056 --> 00:49:21.925 now we have to put new oil into the engine, 00:49:21.925 --> 00:49:23.527 which is done via the filler cap. 00:49:24.127 --> 00:49:28.098 This is literally just a big hole that leads into the timing cover. 00:49:28.365 --> 00:49:30.567 Look, you can even see the timing chain a little bit. 00:49:31.435 --> 00:49:35.615 Pour new oil into here and it will fall down into the oil pan... 00:49:35.615 --> 00:49:38.875 or whatever this is- let's just call it the oil sump. 00:49:39.710 --> 00:49:43.347 However, this car will not need this entire bottle of oil. 00:49:43.647 --> 00:49:46.583 In fact, it would be overfilled if I put the whole thing in 00:49:46.850 --> 00:49:50.454 and an engine with too much oil is also a problem. 00:49:51.154 --> 00:49:53.323 So I'll put most of it in there, 00:49:53.323 --> 00:49:56.827 but then I'll have to check how much oil is inside using the dipstick. 00:49:57.461 --> 00:49:59.830 Which is literally just a stick in a tube. 00:50:00.063 --> 00:50:02.599 And that tube leads to the engine's oil sump. 00:50:03.133 --> 00:50:05.035 The stick has markings on the end, 00:50:05.302 --> 00:50:08.271 and once you've cleaned it using a rag or paper towel or whatever, 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. 00:50:13.076 --> 00:50:16.146 The tip of the stick should have poked down into the oil, 00:50:16.146 --> 00:50:18.949 and you'll be able to see the oil level when you pull it out. 00:50:19.850 --> 00:50:22.452 If you're not seeing any oil towards the markings, 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. 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, 00:50:31.862 --> 00:50:34.398 and eventually you'll start to see the oil in the range. 00:50:34.998 --> 00:50:37.968 I'm going to shoot for just below the full mark, 00:50:37.968 --> 00:50:39.236 which will account for any oil 00:50:39.236 --> 00:50:41.605 which might be sticking to the timing chain and junk. 00:50:42.414 --> 00:50:43.874 And once it's full, 00:50:44.441 --> 00:50:46.176 well that's an oil change. 00:50:46.610 --> 00:50:48.345 It's really quite straightforward. 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, 00:50:53.316 --> 00:50:56.286 is to put the oil cap back on and start the engine. 00:50:56.920 --> 00:51:00.824 But now a note on prefilling the oil filter. 00:51:01.558 --> 00:51:04.461 Some people insist that you should fill the oil filter 00:51:04.461 --> 00:51:06.963 with clean oil before putting it on to the engine. 00:51:07.931 --> 00:51:12.933 The theory is that this oil filter is currently filled with air and not oil, 00:51:12.933 --> 00:51:14.471 and so when I start the engine, 00:51:14.704 --> 00:51:18.442 there will be a brief moment where the engine is running without oil pressure. 00:51:19.709 --> 00:51:23.113 But personally, I think this is a very silly thing to obsess over. 00:51:24.147 --> 00:51:25.087 Why? 00:51:25.087 --> 00:51:27.951 Well, because not only is the oil filter filled with air right now, 00:51:27.951 --> 00:51:30.854 but so is every single one of the passageways inside the engine. 00:51:31.655 --> 00:51:33.256 So forgive me for not thinking 00:51:33.256 --> 00:51:35.959 filling this with oil is going to make a huge difference. 00:51:37.027 --> 00:51:41.164 Granted, this engine has a tiny little filter and some engines have much bigger ones. 00:51:41.698 --> 00:51:43.767 But why don't we take a look at how quickly 00:51:43.767 --> 00:51:46.336 that oil pressure light goes out once I start the engine? 00:51:47.104 --> 00:51:47.637 Okay. 00:51:47.637 --> 00:51:48.839 I just changed the oil. 00:51:48.839 --> 00:51:50.000 Let's crank it up. 00:51:50.000 --> 00:51:51.665 [engine starts] 00:51:54.978 --> 00:51:55.846 Yeah. 00:51:55.846 --> 00:51:57.447 What, one second? 00:51:58.348 --> 00:51:59.516 One extra second. 00:51:59.516 --> 00:52:00.851 It's not a big deal. 00:52:01.151 --> 00:52:04.321 I mean, you go ahead and fill these things with oil if you want to, 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. 00:52:10.227 --> 00:52:13.230 The film of old oil that's sticking to the bearings, etc. 00:52:13.597 --> 00:52:17.033 is going to be enough to prevent damage in the 2 or 3 seconds 00:52:17.033 --> 00:52:20.804 it takes the oil pump to fill even a really big oil filter. 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. 00:52:29.279 --> 00:52:30.614 And assuming there are none, 00:52:31.114 --> 00:52:32.315 you're done! 00:52:32.582 --> 00:52:34.718 We've looked at a great deal of stuff today, 00:52:34.718 --> 00:52:38.922 but we've just been looking at the basic mechanical parts of the engine. 00:52:39.756 --> 00:52:42.359 Yeah, there are a whole lot of spinny bits in there, 00:52:42.359 --> 00:52:45.162 and they all need lots of lube to keep on spinning, 00:52:45.395 --> 00:52:49.799 but they don't start spinning unless a whole lot of other stuff happens. 00:52:50.300 --> 00:52:54.171 For instance, we need to deliver fuel to the combustion chambers, 00:52:54.171 --> 00:52:56.973 and we need to ignite that fuel with a spark plug. 00:52:58.141 --> 00:53:00.310 We use a computer to do those things, 00:53:00.310 --> 00:53:02.245 and we've been doing that for decades now. 00:53:02.712 --> 00:53:05.215 But the computer needs to know 00:53:05.215 --> 00:53:08.852 precisely where each part of this engine is, 00:53:08.985 --> 00:53:11.955 so it can tell when it should do those things. 00:53:12.956 --> 00:53:17.227 In the next video on engine management tech, we'll be looking closely at, 00:53:17.727 --> 00:53:20.096 well, that part, the management part, 00:53:20.564 --> 00:53:24.367 because while this is a very intricate and fascinating piece of machinery, 00:53:24.834 --> 00:53:28.138 it is literally useless without the digital system 00:53:28.138 --> 00:53:30.840 which controls the spark plugs, the fuel injectors 00:53:31.074 --> 00:53:33.476 and even the intake valve timing. 00:53:34.444 --> 00:53:37.180 I'll be covering all of that in the next video in this series, 00:53:37.647 --> 00:53:39.341 so stay tuned. 00:53:40.196 --> 00:53:42.723 ♫ load-bearingly smooth jazz ♫ 00:53:43.360 --> 00:53:45.360 [whirring sound is increasing in speed] 00:53:45.834 --> 00:53:46.334 [schwoop] 00:53:46.334 --> 00:53:47.002 [banging] 00:53:47.221 --> 00:53:48.581 [comically metallic crash] 00:53:48.858 --> 00:53:50.126 It's fine! 00:53:50.760 --> 00:53:51.928 It's fine. 00:53:51.928 --> 00:53:52.996 Nothing happened. 00:53:52.996 --> 00:53:54.698 It just fell off the table. 00:53:54.698 --> 00:53:55.899 It's fine. 00:53:56.233 --> 00:54:01.504 This is the crank pulley and it provides power for the engine accessories. 00:54:02.706 --> 00:54:03.907 That's not working. 00:54:04.374 --> 00:54:08.378 and it provides power for engine accessories such as the alternator, 00:54:08.411 --> 00:54:09.846 the air conditioning compressor... 00:54:12.215 --> 00:54:13.883 I thought you would behave a little better. 00:54:13.883 --> 00:54:15.752 You didn't. You didn't. 00:54:16.375 --> 00:54:18.375 [oh no here we go again] 00:54:20.746 --> 00:54:22.746 [the sounds weren't as funny this time] 00:54:23.059 --> 00:54:24.361 It's fine. 00:54:24.594 --> 00:54:26.029 Nothing happened. 00:54:26.563 --> 00:54:27.764 It's fine. 00:54:28.649 --> 00:54:33.009 So now I guess I need to start plotting my atonement for the bearing/journal decision. 00:54:33.009 --> 00:54:35.072 Does one plot an atonement? 00:54:35.072 --> 00:54:36.348 Well that's not important right now. 00:54:36.348 --> 00:54:42.745 What is important is that you imagine the animated character Doug Funnie writing in his bearing. 00:54:43.374 --> 00:54:45.315 For some of you, that hurt.