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Under the Hood Basics Learn About the Stuff Under Your Cars Hood

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Under the Hood Basics Learn About the Stuff Under Your Cars Hood

Created on: 2020-08-20

This video teaches you the basics of the things you can find under the hood of your vehicle!

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Hey, friends. It's Len from 1A Auto. Today, I want to give you some quick information about some under the hood basics. Right off the bat, I want to let you know that almost everything can be found right inside your owner's manual. If you go to the index, it'll give you an inclination of where you need to start looking, just take a peek and it should go over it all. But I'm gonna make a quick video about it just so you can have a heads up. Let's talk about it.

So, right off the bat, we need to pop the hood of course. To find where you're gonna pop the hood, it'll either be right on the left side kick panel along the side or generally right underneath your steering column somewhere. Go ahead and find it, give it a pull. And now we're gonna get underneath the hood. Now, every vehicle has a different area for their hood latch release right here, this one's right there. Sometimes you'll find it on the hood or even sometimes you'll find it all the way over something like this.

Once you get the hood up, you want to make sure that it's up safely. If it has pistons, make sure it doesn't come falling down on you of course. So just to say right off the bat is every vehicle is gonna have a different location for the items that I'm gonna go over in the video today. Now, in front-wheel drive vehicles, you're gonna notice the engine's transverse, but overall it's gonna have the same general parts. Now we're just gonna start right over here on the left side.

If you were to look right here you're gonna see your brake master cylinder. Attached to the brake master cylinder usually you're gonna see some sort of booster and that's gonna help power assist your brakes for when you're trying to break. The brake fluid reservoir/booster is gonna be someplace located on the other side of the firewall from your brake pedal. Take a look to see if you can see the fluid level. I can see ours right down here, but if I look at the side, I can see that it has a little maximum level sign and it has an arrow pointing right here.

So, theoretically, if this was full, it would be up where my thumb is, this is very low. Two reasons why your fluid might be low. One could be, of course, if your brake pads themselves were worn. If your brake pads are worn, of course, the fluid's gonna be forcing its way down inside there further and it's gonna try to take up that space, so your fluid will look low, or you could actually have a brake fluid leak. If you have a brake fluid leak, there's a couple of places you could look. Of course, look down along where your master cylinder connects to your booster. If you see that there's paint flaking and it looks like it's wet like this, more than likely it's because it has a brake fluid leak in between here and here or even the seals where the reservoir connects onto the master cylinder itself.

If brake fluid is leaking down here, like I said, it's gonna eat away the paint and of course it could cause issues not to mention a brake fluid leak is a safety issue. Other places that might leak would be of course any of the lines that lead from your master cylinder to your ABS unit or ABS unit to your brakes themselves. When it comes time to checking or replacing your fluid, more than likely on the top of the cap or somewhere in the area it'll tell you what type of fluid to use. If for some reason it doesn't necessarily say it on the cap, you can always refer to the owner's manual.

Most vehicles are gonna have a radiator with a radiator cap located right on the top, if it's hot, you definitely don't want to open it. What you're also gonna notice if you have a cap like this is you're gonna have an overflow, that's gonna be the area where your coolant is gonna go when it gets hot and it needs to have coolant inside there so when the coolant cools back down, it can start drawing back into the radiator/cooling system.

This particular vehicle doesn't actually have a radiator cap, what it actually has is a sealed cooling system that comes right here to this. This cap right here needs to be able to hold pressure and it'll tell you exactly how much pressure it should hold. For this particular vehicle, it's 16 pounds of pressure, which you wouldn't be able to tell unless you have a pressure tester. What you could tell is if you have a sweet smell in the air maybe while you're driving around or you're parked someplace more than likely it's because your coolant is vaporizing and coming out of the system. It's very likely that it could be from the coolant cap, in which case you'd probably see some white crusties coming from here. But of course there are other areas on the cooling system that could leak as well, such as maybe your water pump, hoses, or even your radiator.

When you're checking your coolant level, it's important to remember that you don't want to do it when your engine's very hot, when it's hot, it's gonna be under pressure. So if I was to open this up with the engine hot, there's a possibility that coolant or vapor could come spraying up and potentially get in my face. Any time you open something that's a chemical of any sort, you always want to make sure you're wearing hand protection and eye protection.

The reason why you might want to check your coolant level is because maybe your temperature gauge goes shooting up into the hot range which means of course your engine is overheating or maybe you have a sweet smell or a puddle on the ground. At the front of your engine compartment located right behind the radiator is gonna be a fan of some sort. Some vehicles are gonna have an electrical fan which is run by the vehicle's ECU or computer we'll say, and what's that's gonna happen is, as the vehicle gets up to temperature or even above temperature where it should be, it's gonna turn on this fan to help cool the engine. Not all vehicles have an electrical fan, some vehicles have a fan clutch, and I'll show you that.

This is what the fan is gonna look like if it doesn't actually have the electrical fan, this has a fan clutch right here. This won't actually engage until the vehicle is heated up to the point where it's at its normal operating range or even just a little bit above. At that point, it's gonna activate the clutch and this is gonna spin the same speed as the engine speed. Now let's talk about the all-important air filter. If your air filter is dirty in any way, of course it's gonna cause a restriction and your engine isn't gonna be able to breathe the way that it should. Something that you want to pay attention to is of course the air filter housing.

If for some reason your air filter housing isn't connected in properly, of course you're gonna have an issue because you could be sucking dirty air past the air filter and into the engine. If your air filter housing moves around like this, you need to make sure you clamp it up. Let's just go ahead and pop this open since it's already opened up a little bit and we can check the air filter. This, of course, is a pretty new air filter, I don't see any debris inside the areas here which might cause an inkling to want to replace it, so I'm just gonna go ahead and put this back in.

If for some reason you had a lot of stuff inside your air filter and it was very dirty, it's a great idea to replace it. Usually with the air filter system what you're gonna notice on the intake area someplace is a mass airflow sensor. For us here, it has a couple of wires that comes right under there. This one is gonna be pretty hard to see so I'll show you on a different vehicle. Here it is. Okay. So, if you look right along here, you can see what the area where the sensing unit is. If it looks like it's covered in debris or anything like that, maybe it's a dark color, obviously it's very dirty. We have a video all about mass airflow sensors, so if you think that it's an issue, go ahead and check that out as well.

Now let's talk about the power steering system. In most cases, you're gonna have a hydraulic power steering system, in which case you need to have fluid, it's gonna have a reservoir. Some of these reservoirs are gonna be located externally from the pump and other ones are gonna be attached to the pumps specifically. In this case, you have a hose that's going between the two so it's a separate unit. What you would want to do as of course, make sure your vehicle is off, you can go ahead and open this up and then take a peek right inside. You want to take a look at that fluid level and of course the condition of the fluid. It's gonna be kind of hard to see, so if you needed to stick something in there and take a little sample of the fluid, that's completely up to you.

Once you're done, make sure you close it up completely because obviously you don't want any of this debris making its way inside of the system. A lot of times on the reservoir, you might even find areas that look like this, that give you kind of a maximum and a minimum and that's gonna give you kind of an inkling on what's going on with the fluid. If you hear a wine noise from your vehicle when you're idling or even when you're accelerating, more than likely it's from the pump and that's because there's air inside the power steering system.

Some vehicles you might notice don't even have a power steering pump, they're not hydraulically assisted, they might actually be electronically assisted, in which case you don't need to have any fluid. Something that's super important on your vehicle is your engine oil. If you needed to add to it, you would go right through where your cap is located, generally it's gonna be right on one of your valve covers. You could remove the cap. A lot of times it'll tell you exactly what type of fluids you need to use. This says 5W-20, so that's what you would want to use, others might say 5W-30, 0W-20, or whatever the case may be. Others you might just see something that looks like this but it doesn't even tell you, in which case, of course, I would refer to that owner's manual.

When it comes time to check the fluid, of course, what you would want to do is be parked on a level surface and you want your engine to be off. Once you're parked safely on a level surface, you can go ahead and remove this. And of course, as you pull it out, I always like to give it a wipe right off the bat. Before I go ahead and wipe it though, I'm just gonna take a peek at the fluid just to make sure I don't see any like differentiating fluid on there. If you happen to see something that looks like oil and then it looks more like water or some kind of cream up on here, you know that you have an issue.

Let's wipe this off. I'm gonna go ahead and put it back into the dipstick tube here and I'll pull it right on back out. And then this is gonna give us a good inkling of where the oil level is. Anywhere between this top hatch which says maximum and that lower dot right there which says minimum is perfect. So, right here in the center, you can't ask for much better than that in all honesty. When the engine is hot and the oil is hot, the fluid level might rise up a little bit. So if while the engine is cold, it's at the maximum, once it expands, it could be past the maximum, which of course would be very bad for your engine.

If for some reason you happen to notice, I'm gonna wipe this off, that your fluid level was below the minimum, that means you definitely need to add some fluid. If you don't have enough oil inside your engine, obviously that's not gonna be good for lubricating it and of course it could cause engine damage. So if you're at that hatch right there or the bottom dot where it says minimum, between that dot and this one is actually one complete quart of oil. So if I was at the bottom dot I would add approximately three quarters to get it up pretty close to that dot but definitely not above it.

Now, to check your transmission fluid, you're gonna do it approximately the same way in exception of of course, you want the vehicle running. With the vehicle running you want to be super careful while you're standing above it because of course your belt or anything like that could be spinning, or it could be hot in general. With your vehicle parked on a level surface and the engine running, go ahead and remove that transmission dipstick. As we pull it out, we're gonna inspect it real quick like we did on the oil dipstick and we just want to make sure we don't see any differentiating fluid on here. If for some reason it looks like there's red transmission fluid down low and a different color up high, or even vice versa, you know that you have a contaminant inside your transmission fluid. This looks pretty decent, I'm gonna just wipe it off real quick, put it back in, and then I'm gonna remove it and double-check the level. This is of course when the vehicle is running.

So right now the fluid level is actually very high because the vehicle is not running for me. This is just for demonstration purposes, but optimally, if the vehicle was running and on a level surface, you'd be approximately right there. Now, if you have a manual transmission, the clutch master is gonna be pretty close to your master cylinder for your brakes. So you just locate that. Usually, you can look right on the cap and it's gonna tell you to use some sort of fluid in it. Generally speaking, it'll probably be brake fluid, in this case it's dot three brake fluid.

Now the most common fluid that you're probably gonna check underneath your hood is more than likely gonna be your washer fluid, it's gonna come in a reservoir because of course it needs to have plenty of fluid for you, you just pop that open, you can take a peek right inside there. Overall, there's gonna be different color washer fluids that come out to be different types of washer fluid. So sometimes there's gonna be green, there's gonna be orange, there's gonna be blue, there could be all sorts of colors. If you happen to see brown, more than likely that's because somebody added a little bit of orange with their blue or with their green.

Overall, washer fluid is supposed to be able to wash your windshield. So when you're driving down the road, if you happen to get a splatter or a bug or something like that, it needs to wash it down. So would I say that the washer fluid is important to make sure that it's full or at least, you know, has some in it? Yeah, because your vision's imperative. So now let's talk about the electrical components that you're probably gonna find underneath your hood. Every automotive vehicle is gonna have a battery of course, the battery is gonna be the lifeblood of your electrical system. If for some reason there's an issue with the battery, it could cause all sorts of havoc with your electrical system in your vehicle.

The battery needs to be in good condition and overall they only last three to five years generally speaking. Other things that you'd probably want to pay attention to on your battery is of course the terminal ends. If it looks like they're corroded or they have any funny colors growing around them, more than likely that's corrosion and it's gonna cause a restriction and could potentially drain your battery over time. Something else that's super important to think about with the battery is it needs to be held down by something. They should have a battery hold-down, this one has a location right here, other battery hold-downs might come up and across the top of the battery, but mainly they need to keep the battery from jonsing around and/or, you know, coming out of its spot. If you hit a bump, the last thing you want is this jumping out and potentially grounding out against something.

If your battery is loose like this, obviously that's not very good. Something else to think about with the terminal ends is to just make sure that they're tight. If your terminal end can move around like this, there's a possibility that it could, of course, come free completely from the battery, which would be very bad, or even worse, if it was just loose and it started bouncing around making connection, breaking connection, making connection again, you could cause potential damage to your vehicle's computer.

Now, moving along to your vehicle's computer, you might happen to notice that it's located under the hood, other times it might be located inside of the passenger compartment, but sometimes it is here. With that said, it's not necessarily something that you're gonna want to maintain in any way, there isn't anything that you're gonna be able to do in exception of just kind of grab onto the wires and make sure that the connections don't move around. You also want to pay attention for funny colors such as corrosion because that could cause an issue. If you happen to see any issues with these, of course, that's something that you're gonna want to have serviced. Under your hood, you might notice you have a fuse box. Sometimes you'll see the legend on the top or maybe even sometimes you'll see it on the bottom of the cover. Of course, under that is gonna be some fuses and relays, you don't necessarily have to mess with those unless of course you're trying to diagnose an electrical issue.

Another electrical aspect that you're probably gonna find under your hood is of course the ignition system. Some vehicles are gonna have a coil that looks like this and it might be located separately from where the spark plugs are, other vehicles are gonna have a direct coil that sits right over the spark plug. If you have a coil that's separate like this, more than likely you're gonna have wires that lead down to the spark plugs. Some vehicles will have a distributor cap, looks like this right here. And of course that's gonna have wires coming out of it, those wires are gonna end up leading down to your spark plugs which would be located either on the side of your engine, the top of your engine sometimes, or even on the front and rear.

Something else that's super important on every vehicle is your alternator, the alternator is what's gonna be charging that battery. So if your alternator's no good, you're gonna be running off of your battery only and of course the battery is gonna drain out over time. Now, since we're talking about the alternator, you're gonna notice that you have your serpentine belt that runs across it. That serpentine belt of course is gonna go across a whole bunch of pulleys along the way. With those pulleys, what you're gonna notice is they're grooved on a lot of them. If for some reason your serpentine belt wasn't lined up when it was put onto the vehicle, maybe somebody serviced it or replaced it, it could be hanging off the side a little bit in which case it's gonna cause severe damage to your belt. If your belt looks like this and it's missing a groove, obviously that's no good and of course you'd want to get any of this out of there.

If your vehicle is equipped with AC, you might see some lines that look as though they're wet, that's bound to happen when the AC is running and that's due to condensation. The gas inside of your AC system is gonna be very cold and the air outside of the AC system or inside your engine compartment is gonna be very hot, that causes condensation and that would cause the water that you see underneath your car. There are gonna be other components underneath your hood that I haven't actually gone over in this video and that's only because this video is supposed to be fairly basic and just kind of go over the general things that people want to pay attention to.

Okay, friends. So we tried to make you a nice educational video on basic things that you should look for underneath the hood. There's a lot of stuff that we covered in this video, so let's try to keep it simple for you. The main things that you want to pay attention to is of course your battery condition and the condition and levels of all of your fluids. Aside from that, unless something goes wrong, you really shouldn't have to worry about it.

One last thing I want to mention, inside of your owner's manual you should see something that looks like this, and it's gonna tell you your service, this is for the maintenance. Just try to keep up with this as close as possible and you'll be doing all right. I almost forgot, if you liked the video, make sure you smash on the like button for me, it would mean the world. While you're at it, why don't you go ahead and subscribe and ring the bell, that way there you can be kept up with all of our latest content. Thanks.

Thanks for watching. Visit for quality auto parts shipped to your door. The place for DIY auto repair. And if you enjoyed this video, please click the subscribe button.

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