Mechanic Answers Car Questions

I'm mechanic Jared Pink,

host of The Questionable Garage.

Let's answer your questions from the internet.

This is Mechanic Support.

[groovy upbeat music]

TheGeek00 asks, Is there any reason to use a dealership?

Sometimes yes.

The newer cars, software is not always yet available

to an independent shop,

so sometimes you're stuck going to the dealership.

If your car's under warranty,

your work's getting done for free at the dealership.

There are trustworthy dealerships out there,

so there is benefit going in there.

They're generally always going to be

using manufacturer parts, and they have the full access

to all the manufacturer information.

It does come at a premium, so you have to decide:

is it worth your dollars?

For certain vehicles, absolutely,

because it's going to hold a higher resale,

but that's if you're buying an Aston Martin, Lamborghini,

like the super top-tier brands.

If you're in a Toyota, Kia, most of your Chevrolets,

you're gonna get good service at a dealership,

but you're also gonna be able to get good service

at an independent shop.

Here's a question from Quora:

How do I know if I'm buying a 'lemon' car?

So let's say you are in the market for a used car.

You go to that used car lot,

and you're looking at something you find

and you really do like.

How do you know if it's a lemon?

One thing you really need to try to do your best

is find its history report.

Look into its background.

There's tools like CARFAX and AutoCheck

that are going to pull the title history.

If you pull up the car, it's five years old,

but it's had eight owners,

might not be a good car 'cause it's changing hands a lot.

The other thing you might wanna look for in that report

is if you see a ton of repairs

that aren't normal maintenance and service.

Also, something that TitleCheck's gonna reveal

is if it is a branded lemon buyback.

So manufacturers, when they sell a new car,

if it's deemed unrepairable at some point,

it gets branded a lemon, goes back to the manufacturer,

they eventually fix it and resell it.

Something else that you need to be careful of

is if it's an older car, but it looks way too clean,

like there's been a lot of extra detail work;

make sure they didn't polish it up

a little bit too much to hide a problem underneath.

From the AskReddit subreddit:

As a mechanic, what car do you drive

and what cars would you never own?

Well, my daily driver is a mid-2000s Chevrolet.

They pretty much GMT800s;

you have the Silverados, the Tahoes; they're bulletproof.

They go forever,

and even when they're broken, they're still gonna drive.

Now, something I would probably really steer clear of

as a mechanic, meaning I'm gonna have to fix it,

is that same generation's Mercedes.

Anything mid-2000s Mercedes,

when they're working, they're great.

When they break, it gets very expensive very quick.

@pin_to_primer asks, If an electric vehicle breaks down,

do you call a mechanic or an electrician?

Long before electric cars, cars had electrical systems

we had to find faults with and fix.

So you're gonna wanna bring it to your mechanic.

Now, one thing with electric cars:

a lot of people think they never need maintenance,

but believe it or not, you still have gears inside that car.

The electric motor needs to turn something

to end up turning your wheels,

and that goes through a traditional gear.

That gear needs to be lubricated.

So you still have oil inside your electric car

that does need to get maintenance.

Granted, it's, like, every 100,000 miles,

but more importantly, your brakes on your electric car,

'cause they don't get used as much, need regular service,

especially if you live up in the Rust Belt.

So if you break down, you're gonna go see your mechanic,

and you should probably see him before you break down

to keep your electric car running.

@car0o0o0o0oline asks, I know my car is a man

because he's terrible at communicating.

What does a little light up wrench on my dashboard mean?

Just tell me what you're feeling.

A lot of cars do have a lot of crazy

lights that will pop up,

and they can be very confusing.

In your glove box, you're gonna have an owner's manual

that's gonna help you out.

But what you're asking, a yellow wrench in a hand,

that's just letting you know

your car needs some maintenance.

An oil change or tire rotations

is just saying, Hey, I do need some help.

And it's trying to communicate.

You wanna see it sooner than later.

@haydennolson asks,

Is premium gas really better for your car?

It all depends.

Does your car call for premium gas?

Now let's explain really quickly: what is premium?

You have all of your different octane ratings.

The higher quality, or higher octane rating, gas

just means it's better at resisting explosions.

Sounds backwards.

You'd think a higher quality gas would explode easier.

Its job is to only explode

in the engine when it's supposed to.

Now I use explosion

because that is how your car actually runs:

a very specifically timed explosion where all of that fuel

that's got pumped into the cylinder explodes

and pushes the piston back down.

That happens a whole lot of times every second,

and it needs to happen exactly when it needs to.

Otherwise, you're gonna damage your engine.

If you're driving most German cars,

if you're driving a car with a turbocharger

or a supercharger,

it's gonna tell you minimum octane 91 or above.

That is when you're gonna need to put the premium in.

@happyiris9 asks, I hate adulting.

Like, how do I find a good mechanic?

There are lots of good mechanics out there,

and there are some people that unfortunately

are gonna take advantage of you for not knowing.

One of the best things you can do, ask your friends.

If they're getting work done, do they trust their mechanic?

When they go in, do they feel like

they're being treated fairly by their mechanic?

The other thing you can do: drive by,

and if you see a busy mechanic shop

and you know you need some work, you're new to the area,

stop by, go in, introduce yourself,

look at their cars, their work process,

and will they even take the time to talk with you.

If you pull up to the shop, you're in a busy town,

and they don't have a single car,

and you have four mechanics ready to run

and take care of you, they're not busy for a reason.

So take that as a red flag.

You want a mechanic that you know you can trust

who's gonna help keep your car running,

take care of the service for you,

and fix it when it unfortunately breaks.

From the mechanic advice subreddit,

How can I make my car last forever?

Well, that's only a diamond that's gonna last forever,

but you can make your car run for a very long time.

Realistically, let's say 300,000, 400,000 miles.

If you do all of your preventative maintenance,

you're gonna spend a lot less in repairs in the long run.

So it's a great return on investment.

That's the best thing you can do.

You got manufacturers telling you 10,000,

15,000 on oil changes.

I'm a big fan of 5,000.

It's one of the cheapest things you can do

to keep that engine happy and healthy

'cause oil is cheaper than an engine rebuild.

It's the lifeblood.

The next big thing: transmission fluid.

Almost all manufacturers now are telling you

it is a lifetime fluid.

Well, to them, a lifetime is at most 100,000 miles.

So I'm a big fan

of about a 60,000-mile service interval on it.

Your coolant: 80 to 90,000 miles,

you do wanna change your coolant out,

and you wanna make sure you put the right type in.

There's OAT, POAT, there's so many different types.

Make sure you put the right oil in for your manufacturer.

And when it comes to synthetic or conventional oil,

if you're doing a really long service interval,

make sure you're running synthetic.

If you're doing a 3,000, 5,000-mile range,

you can do conventional.

Ultimately, the best thing you can do is go ahead

and pull up the factory minimum service intervals.

That's the least you should do to it,

and do a little bit better.

You might just turn that car into a diamond.

@nikii_colee asks, What happens to your car

if you put diesel in it instead of gas?

Asking for myself because I'm an idiot.

Well, you're not an idiot.

You made a mistake.

Well, first off, your car won't run.

You're gonna have to get it towed,

and you're gonna have to have

all of that diesel pumped out.

Now, you may have a mechanic

that claims you're gonna need new injectors,

a whole fuel system.

Really, what has to happen, your tank needs to get drained.

You're gonna probably need some fuel filters,

and it's gonna take a little bit of gasoline

to flush all that last of the diesel out.

Now, when it comes to mistakes, diesel in a gasoline car

is a lot better than gasoline in a diesel.

If you ever do the opposite, gasoline in the diesel,

don't even attempt to start it; get it towed;

flush it very, very quickly

because you do risk serious, very expensive harm.

@ghostwritingcow asks, Chevron marketing is genius.

I have no idea what the heck Techron is,

but it makes me think Chevron with Techron

is better than other gas.

It is an additive package.

Now, most gas comes from two or three different refiners,

but all of your different gasoline vendors,

BP, Shell, Sinclair, Chevron, they add their own additives.

Additive packages help condition the gasoline.

There's a little bit of cleaners.

There's stabilizers.

There's things that just make the gasoline

a little bit better.

So while you can buy your additives in a bottle,

you don't have to.

As long as you're stopping and buying your gasoline

at a major named brand store,

you've already got your Techron in it.

@N1CKRICH asks,

Why do mechanics offer to rotate your tires?

They literally rotate all day long,

and he is serious about this question.

Well, when we're rotating your tires,

we're not just spinning them on the hub.

We're actually going to take the tires

that are in the front, move them to the rear of the vehicle,

and the rear tires to the front.

If you have a full-size spare,

sometimes that will get rotated into the mix,

and it actually will help give you a much longer tire life.

Now, the reason this is happening is the tires in your front

are doing things very different than tires in the back.

The front you're having to steer;

about 70% of the braking happens up front,

whereas the rear tires,

generally you're just kind of hanging out.

Also, most places that you buy your tires

will offer you free lifetime tire rotation,

so it doesn't hurt to go in every five to 6,000 miles

and get them rotated.

rawturbo asks, Are older cars built better

and more reliable than new cars of today?

No, there's a lot of rose-colored glasses.

Everyone thinks about how wonderful the '70s

and the '80s were, the '90s,

that they are the ultimate of all cars ever built.

Most of your older cars had a life expectancy

of 100,000 miles,

where again, 200,000, 300,000, 400,000 miles

out of modern cars is much more common.

The other thing that you find in a modern car

is they are substantially more fuel-efficient.

You get a lot more horsepower out of smaller engine sizes,

so modern cars are built a lot better.

A lot of the reliability concerns come from the simplicity.

Your car from the '70s is much simpler.

You don't have computers;

you've got two or three basic components,

and that's what's gonna make it run.

But your modern car, you're gonna have 30 sensors sometimes,

all working in symphony

to make your car work perfectly.

As far as what car should you buy, what do you like?

If you wanna just jump in and go most of the time,

buy something modern.

If you wanna look cool

and have some loud, rowdy muscle car,

buy you an old muscle car.

From the NoStupidQuestions subreddit:

Is nitrous in 'Fast and Furious'

a real thing that people can have in their cars?

Can you magically shoot a chemical into your engine

and make it go faster?

Yes. [laughs] [canister clanking]

Yes, you can.

Nitrous oxide is a real thing.

Now, in the movie, they sensationalize it.

You see purple flames, and that's not quite how it is.

It shoots a concentrated oxygen into your engine

to make more power.

The beauty of nitrous oxide

is it's a relatively simple thing

to add to just about any engine out there.

You can bolt this on with some extra fuel jets,

turn it on, and boom,

you can have up to 25% more horsepower for most engines.

Now, one other thing you see in the movies

is a car gets shot up, and nitrous explodes.

This is just your oxygen.

Without that fuel, it's not gonna explode.

Again, most modern nitrous systems are pretty safe,

and as long as you install and set it up correctly,

your engine's gonna be safe with it as well.

Another way you can add that extra air

and oxygen into your car,

you've seen these in Fast and Furious as well,

is a turbocharger.

They're very expensive to initially install,

but once they're installed,

this is ready to inject all of that air at all times.

Now, some cars actually come factory turbocharged.

They're incredibly efficient ways

to get that extra air into your engine

to make more horsepower.

Adamola asks, Bro, how do mechanics

listen to your engine for three seconds

and immediately know what's wrong with it?

Experience.

When we have worked around cars for a very long time,

we know what certain engines sound like

and what they shouldn't sound like, and it helps dial in

and identify those problems very quickly.

So if I were to hear a sound like this,

[engine clattering]

I would immediately know

to start looking at a serpentine belt idler pulley.

You can kind of hear that chirping sound,

and it's spinning about as fast as the engine RPM.

Now, if I hear a sound like this,

[engine whirring]

I'm gonna let the customer know

he's gonna have a very bad day

'cause that sounds like a major engine bearing knock,

and it's about to get very expensive.

Now, if you end up hearing a sound that sounds like this,

[engine rattling]

believe it or not, that's normal.

Most fuel injectors on modern cars are actually pretty loud,

and that's why you see the engine beauty covers

with foam on it

to try to make it so you don't hear it as bad.

aniya asks, What's funny

is that I don't even know what tire pressure is.

Tire pressure is one of the most crucial things

to have good fuel economy, good driving performance,

and make the car perform the best it can.

The only thing that's connecting your car to the road

is your tires.

First, you need a tire pressure gauge.

Now, in the US, we use PSI; they use Bar overseas.

It's telling you how much pressure

and force is pushing against the rubber.

If you have severely underinflated or overinflated tires,

you can actually damage them.

If you have a vehicle since 2006, I believe it is;

they all have active tire pressure monitoring,

which means you can push a button

and your car is gonna tell you

how much air is in each tire.

That is a pressure reading, not a percent.

So how do you know what to do

and how to check your tire pressure?

Well, first you're gonna wanna open up

the door of your car, the driver's door.

Usually the sticker is either on the door itself

or on the B-pillar.

That's gonna give you the tire size

and the pressure that you should have in each tire.

Next, you can either buy your own small air compressor,

go to a gas station.

There's lots of air service pumps around,

and then you'll wanna fill it to that pressure.

Now I will caution you: bring your own gauge.

If you have to, those real cheap 99-cent ones,

they're good enough,

but the gauge that's on that machine that you're using,

it's been abused a lot.

Now, the other option is some of the new cars

are really tricky.

You can tell them that you're inflating the tires

and it'll honk the horn at you

when the air pressure's right,

but I still like to go with a mechanical gauge,

double-check it.

IamDanielChai asks,

How do mechanics figure out why a car died?

They perform an auto-opsy.

Well, I think that was meant as a joke,

but that's actually a really good question.

How do we figure out why a car died?

Well, first, exactly how is it dead?

When you turn the key on, does anything power up on the car?

If nothing powers up, we're gonna check the battery,

make sure there's voltage.

If it starts to power up but then runs really rough

or doesn't run at all,

we're gonna pull out one of our diagnostic scan tools.

We can connect to the vehicle's data port

and see everything the computer's seeing,

and that's gonna help us narrow down and figure out

what electrically has gone wrong with the vehicle.

Now, if it's a mechanical failure,

we try to turn the key and try to crank it,

and nothing happens, or it's knocking incredibly;

that's when the fun really starts to happen.

We have to take apart an entire engine.

Here, we have some parts of a major failure.

This is your oil pan.

This sits at the bottom of the engine.

It holds all of your engine oil,

and if you look close inside,

there's a lot of metal inside this one.

That means something has blown up really badly.

All of that metal comes from the bearing halves

that lives under your connecting rod,

and this particular engine was knocking

and ate its bearings.

Oil needs to lubricate all of the bearings,

and when the engine's running correctly,

it's actually riding on oil, not the bearing.

The bearing is there for when the oil goes away.

So at this point, in this auto-opsy,

we know we have a lot of bearing material,

and we have a spun connecting rod bearing.

[crankshaft thudding]

There's not a delicate way for that.

So when we start looking at this crankshaft,

we know in this particular engine,

oil flows from the front of the engine to the back,

and we could look and see the front of the engine

looked perfect, no bearing damage,

everything is perfectly fine.

Then suddenly we get to this main bearing,

and we discovered it actually did

what's called spinning the bearing.

This bearing is now moving in a way it's not supposed to,

and once it's done that, it blocks off the oil

to the connecting rod and ruin those bearings.

So we take all of that information,

and we try to figure out why did we spin a main bearing.

And what's really sad is this incredibly expensive engine

was ruined because it was a half quart oil low.

So we go back to that phrase from earlier:

oil's the lifeblood of your engine,

you gotta take care of it.

Make sure you got the right amount in it.

$5 worth of oil did about $8,000 in damage.

Xcspi from the askcarguy subreddit,

How do you pick out a project car to buy?

I love this question

'cause that means you're wanting to wrench.

First, what cars do you like?

There's no point in buying something

you're not gonna enjoy working on.

Two, one of the most important things I would suggest,

see how much information is out there.

If you're buying some weird, obscure car,

trying to figure out how to work on it,

it's gonna be really hard.

So with cars like a Miata,

any generation of the E30, E36 BMWs,

early '80s Toyota Corollas,

there's lots of information out there,

any generation of Honda, all phenomenal project cars.

They're things that, if you end up not being able to fix,

you're still gonna be able to sell for your parts

and not lose out a lot of money.

Now, I definitely was there long ago.

I found small, fun, simple project cars,

but I've kind of graduated a little bit in project cars,

like, you know, shoving a whole Corvette suspension

and engine in an old farm truck

because I couldn't buy a ball joint.

I put a Chevy Big Block in a Nissan 300ZX

to do nothing but giant burnouts

and win Hot Wheels contests,

or turning four-door Dodge Chargers

into pickup trucks with cop car lights.

So, from the MechanicAdvice subreddit, crashdummy45 asks,

What are some tools that every mechanic should own?

Funny you should mention that.

I've actually put together

one of my favorite beginner tool sets here.

Now, some of the absolute crucial things

you're going to need is a good socket set.

Now, my particular set, I've got quarter-inch,

three-eighths, and half-inch sockets in both SAE and metric.

You're gonna need a really good set of screwdrivers

because you don't know what you're going to need to fasten

for clamps or interiors.

Another thing you're gonna want

you're gonna need some good pliers,

a good pair of side cutters, absolutely crucial.

You want to spend a decent amount of money on your pliers

'cause nothing's more frustrating than cheap pliers.

The other thing you're really gonna wanna do,

get a good wrench set.

I've got all of your common sizes, both metric SAE.

That's gonna get you set up

to be able to do just about anything.

Now, if you're working on something like a European car

that has a lot of triple squares,

a lot of the General Motors with Torx sets,

you're gonna obviously need to add that in,

but at its core, you need a good, solid socket set.

You're gonna need some basic wrenches,

and that's gonna get you covered.

@escaljacks1 asks, What does engine coolant do?

It helps keep your engine cool.

Anytime you're converting one type of energy to another,

electric cars, gasoline cars, it's not free.

It's gonna generate some heat,

and the coolant's job, along with the radiator,

is to transfer that heat away.

What a lot of people don't realize is coolant's designed

to raise the boiling temperature of water

and also lower the freezing point

so you're able to drive it on the road.

Anytime you need to top off your coolant,

one, you probably have a leak,

and you do need to identify it,

but make sure whenever you do add coolant,

you're putting the correct kind in for your vehicle.

And also, at most parts stores,

you can buy a 50/50 ready-to-use coolant

that saves you from having to mix

distilled water with your coolant.

@hailyelena asks, Do I really need an oil change,

or is it just, like, a scam?

You do absolutely need an oil change.

I keep preaching it.

It's the lifeblood of your engine

and the easiest way to keep it running the longest.

So let's do an oil change together.

All right, so the first step of your oil change:

safety gear.

Second step: you need your vehicle in the air.

Now, there's fancy modern ways

where you can use extraction tubes from the dipstick.

I'm old-fashioned.

I like pulling the drain plug

because you're not gonna suck any small debris out.

You can check and make sure your engine's healthy.

I always like to pull the oil filter off first,

so we're gonna get our oil drain

kind of in a good position here.

So you'll see people fight removing an oil filter.

If you put it on correctly,

you snug it and go another quarter turn.

So I'm gonna be able to reach up here,

get a little bit of a twist,

and we're gonna get this oil filter coming out.

This is your oil filter,

and its job is as your oil is gathering

and collecting all the particulates,

this is gonna collect it and scavenge it

and keep it from rolling around

all of your lubrication system.

We're gonna let that keep draining,

then we're gonna come to our drain plug and loosen that.

This is the fun part.

You get to check and see if any chunks come out

when you remove your drain plug.

So right now we've got the dirty oil draining out.

The good thing is it's just a little bit black,

which is expected of old oil.

Again, it's catching and holding

and suspending all of the combustion debris,

the carbon deposits.

There's nothing alarming.

We didn't hear any chunks of metal or nothing coming out.

So we're just gonna let it run,

and then when it's all done,

we're gonna put the drain plug back in.

So now we still got a little bit of oil trickling out,

we can go ahead and put our new oil filter in.

Make sure you're using a good quality filter.

There's a lot of arguments of prefill

or don't prefill your oil.

I don't like to prefill an oil filter,

but you do need to lubricate the O-ring of your oil filter.

So one of the number one things you need to do

before you put your oil filter on

is make sure that O-ring didn't stick to the engine.

Sometimes it does; you'll double-gasket,

and that's gonna blow out.

What I like to do is I'll just simply

dip my glove finger in, get a little bit of fresh oil,

rub it on that O-ring surface,

and you put it on the oil filter pedestal.

There, it's tight, and quarter turn.

Then the last thing before we set it back down on the ground

and fill it back with oil

is you got to put your drain plug in.

Now, this has a really good O-ring gasket.

I can reuse it several times.

A lot of times you're gonna have to replace

that rubber seal every time.

So double-check your car;

make sure you're doing the right thing for it.

Then it's just a matter of thread it in.

Now you can wait until it completely stops dribbling,

one drip every second.

That's low enough.

And then give it a little snug, wipe off all your oil mess,

lower the car, and fill it up with oil.

And that's how you do an oil change.

Well, those are all the questions for today.

I hope you learned something,

and thanks for watching Mechanic Support.

[light groovy music]