Previously on How to Adult, we covered some basic car maintenance stuff you could do monthly to keep your car running in tip-top shape.

This time, we're gonna get a little more involved and... check under the hood. [♪♩INTRO]. First, I would recommend not wearing clothes you really like.

Or anything white, even before labor day. It turns out a car's engine is pretty dirty, and we're going to get in there to check some fluids. Yes, fluids.

Even though your car goes through gas the fastest, it needs all sorts of other fluids to keep running, too. You should have your mechanic check and change them if needed every six months, but it's also important to check them yourself in the meantime. But first, we have to do some prep work for safety.

Step one: Park the car on level ground and turn it off. The engine has things that can cut your fingers off if they're moving. Please don't cut off your fingers off.

You need them. Also, you want to let the engine cool down for a while if it's been running. Things can get hot in there, and you don't want to burn yourself.

Step two: check your oil. Checking your oil is fairly easy, and you can do it a little more often than the other fluids here—most mechanics recommend you do it every other time you fill up your gas tank. Grab a paper towel or rag, then pull the dipstick out.

If you're not sure where that or anything else we're talking about is, check your manual. The location is different in every car, but it should be listed in your manual's maintenance guide. The first thing to look at is the color and consistency.

A little bit of gunk on the inside of the cap is normal, but too much is a sign of something bad. The oil on the dipstick should be dark brown or black, or amber colored if it's new. If it's really gray or milky, you may have water or coolant in it.

That's bad and you should get it checked out immediately. You should also look for any debris. If there are flecks of metal, that could indicate a problem inside the engine.

Once you've looked for that stuff, you can check the oil level. Wipe the dipstick off top to bottom to get all the oil off. It sloshes around in there while you're driving, so in order to check the actual level we need to reset the dipstick.

Put the dipstick all the way back into its tube, then pull it out again and take a look. There should be some sort of level indicator: cross-hatching imprinted into the metal, or lines labeled LOW and HIGH. Something like that.

The oil should be somewhere in that zone. If the oil is too low, you can buy and add more. It usually comes in quarts, and you can find them in many gas stations along with a funnel.

Once again, check the manual: it will tell you what weight and viscosity oil your car needs. This is important! If your car takes 10W-30 oil and you put in 5W-40, the oil won't do its job quite right, and it'll reduce the lifespan of your car.

Also try to be aware of whether the oil in your engine is synthetic or conventional. Mixing them isn't the end of the world, but it's better if you can keep it consistent. Newer vehicles tend to use synthetic.

Once you have the right kind of oil, your manual will tell you where to add it. Only add a half quart at a time using a funnel, and wait a few minutes for it to settle before you check the level again. Step three: wiper fluid.

Windshield wiper fluid is really easy to check: most cars have a translucent white reservoir that's pretty obvious. It usually even has the same little wiper spray symbol as the switch inside the car that turns it on. If you look inside, there should be a level indicator.

Just fill washer fluid up to that line, and you're set! Like replacing any of the fluids here, it's going to be easier and less messy if you use a funnel. Just make sure that you don't cross-contaminate things.

You don't want oil in your wiper fluid reservoir. Step four: coolant. Engine coolant can usually be found in one of two places: either a translucent white reservoir similar to the wiper fluid reservoir, or, in older vehicles, right in the radiator itself.

I mean, it ends up in the radiator at some point either way, but sometimes there's no external reservoir. That's less common nowadays, though, and you probably shouldn't mess with the radiator itself if you can avoid it. The most important part of checking your coolant is making sure your car isn't still warm from running when you do it.

Coolant gets really hot and really pressurized when your car is on, so if you're not careful you can get a face full of boiling steam and coolant. Most cars have a safety system in place to prevent the caps from coming off when the system is pressurized, but it's not guaranteed—especially on older vehicles. Don't risk a really lame Batman villain origin story just because you're not sure how hot the engine is.

Just wait. Once your car is cold, you can pop open the cap on the reservoir. Check the color and consistency of the coolant. [mine has debris in it, which isn't ideal].

It shouldn't have any debris in it, and it shouldn't look brown or oily—your manual can tell you exactly what color it should be, but it'll probably be bright green, orange, yellow, or maybe even clear if your engine runs on diesel. If it is brown or oily, you should have it checked by a mechanic. There should be an indicator somewhere to tell you where the cold fill level is for the coolant.

If you need to, you can add more. Once again, your manual should tell you exactly what kind of coolant you need—which, by the way, is never water unless you're in an emergency situation. Water can work as a temporary fix if you end up losing a bunch of coolant somehow, but it can rust or freeze your engine so it's something that should only be used to get you to the repair shop.

After that, it should be replaced with coolant, or you start reducing the lifespan of your engine. Pay attention when you buy your coolant, as well—some needs to be mixed with water at a specific ratio, while other stuff comes pre-mixed. It's typical for coolant to be a 50/50 mix of antifreeze and water, so you don't want to add just the concentrated version or dilute the pre-mixed version.

If you do, you could run into problems. Step 5: check the battery terminals. Some cars have their battery hidden away, but if you can see it, just make sure the top terminals aren't covered in corrosion or gunk.

If they are, you can disconnect the battery and clean them up. Always remove the negative cable first—it's marked with a minus sign and has a black cable or cap. Once the cable is loose, you can swing it out of the way and secure it.

Then you can carefully remove the cable from the positive terminal—the red one with a plus sign—and secure that out of the way. Just make sure that nothing ever touches those two terminals at the same time—it can lead to a nasty shock. Using a wire brush, wipe each of the terminals and both cables clean of any corrosion or buildup.

Baking soda and water help a lot. Just make sure not to get the debris on you or your clothes. It makes acid when mixed with water and can eat holes in your sleeves or skin.

If you do get some on you, just rinse very, very thoroughly with water. Then, when you think you've rinsed enough, rinse some more. Dilution is the solution to your pollution.

Once you're finished, you can put the cables back on the terminal, but in reverse order—this time the positive cable goes on first, and then the negative cable will go on. When you're done with that, you're done under the hood! Good job!

Now, technically there are a couple other types of fluid you could look at, too, but they're more involved, so you shouldn't mess with them unless you are very comfortable with your car and have really good health insurance. Like, there's a whole thing with a hoist and some bolts and a pan, and you have to have the engine running for some of them ... you don't want to get into that. Just have a mechanic check them when you bring it in for an oil change.

Step six: hit the road. Now that your car is maintained and clean, it's time to live your life a quarter mile at a time. Whether you want to be fast and furious or just gone in 60 seconds, you can rest assured that your car is ready for a good cannonball run.

Or just drive to work and back. Either way, if you remember to do these checks, you'll help your car live a long, healthy life and in return, it will get you where you need to go. Thanks for watching!

If you want to support How to Adult creating videos like this, consider visiting our patreon page at patreon.com/howtoadult and become a patron. If there are flecks of metal, that could indicate a problem inside the bleh bleh bleh... Okay.

This looks like a piccolo in the corner of my eye. Just make sure that you don't cross-contaminate things. [mumbly] You don't want fluid in your wiper fluid reservoir... This is my 'dish soap' of this—of this script.

Either a white translucent we—rew—pshhh. Okay. Okay.

Alright. Ohhh-kayyy. [off-screen] I think that's good. Yeah. [Rachel's tough voice] It's going to have to be! [laughter] [sad] Do I have to say reservoir? [laughter].

Like, there's a whole thing with a hoist and some boils and a pan... [off-screen] I think it's 'bolts' not 'boils'. Oh. There's a glare! [laughter].

There's a—. I was wondering what that was!