The "Ask a Mechanic" Thread (merged)

[Rumrunner6900]

The air keeps blowing, but turns cold.

[twa]

probably the air blend door then, you can try to look under the hood for a cracked vacumn line,,usually a black plastic (or listen for it), but other than that a mechanic is best

[Koolblue13]

00' Chevy Malibu 3.4L AT.

Cold start engine reves up to 2k and back down. Up and down, up and down. Once it's warm, it's fine.

What gives?

[SpringfieldSkins]

00' Chevy Malibu 3.4L AT.

Cold start engine reves up to 2k and back down. Up and down, up and down. Once it's warm, it's fine.

What gives?

Most likely an intake manifold gasket (or manifold) that is leaking air into the engine. Second thought would be a failing idle air control motor.

[Skinz4Life12]

00' Chevy Malibu 3.4L AT.

Cold start engine reves up to 2k and back down. Up and down, up and down. Once it's warm, it's fine.

What gives?

too much of that salty sea air!

[Koolblue13]

too much of that salty sea air!

No such thing

Most likely an intake manifold gasket (or manifold) that is leaking air into the engine. Second thought would be a failing idle air control motor.

Idle air control motor is kind of what I was thinking. I am suppose to work on somebodies car, but I've been stupid busy at a new job and don't have time to mess with it. How would I know if it's the manifold? Just spray carb cleaner around it like a vacuum leak?

[landrydirty30skins]

Id check the carbon on the throttle plate first, it could be sticking

[SpringfieldSkins]

No such thing



Idle air control motor is kind of what I was thinking. I am suppose to work on somebodies car, but I've been stupid busy at a new job and don't have time to mess with it. How would I know if it's the manifold? Just spray carb cleaner around it like a vacuum leak?

Yeah, spread carb cleaner around the gasket when it's happening. If the idle clears up then you have your answer.

[Koolblue13]

Yeah, spread carb cleaner around the gasket when it's happening. If the idle clears up then you have your answer.

Alright, thanks a lot.

I have answered a ton of questions in this thread and it's been nice to be able to get an answer when I needed it. Thanks SS.

[RVAbrendan]

I had a gas leak in my fuel tank (must have hit a nasty bump on a construction road), so a buddy mechanic of mine repaired it with an epoxy kit meant for the job. Was driving home from work yesterday, left the car on to go into 7-11, came back out and looked under to see gas leaking out like a faucet.

Sounds like I need a new fuel tank. Dude said he found one for $100. Is it worth it to get this replaced? I drive a 1993 toyota Corolla...

[Koolblue13]

I had a gas leak in my fuel tank (must have hit a nasty bump on a construction road), so a buddy mechanic of mine repaired it with an epoxy kit meant for the job. Was driving home from work yesterday, left the car on to go into 7-11, came back out and looked under to see gas leaking out like a faucet.

Sounds like I need a new fuel tank. Dude said he found one for $100. Is it worth it to get this replaced? I drive a 1993 toyota Corolla...

Yes, dear god yes. Do you think leaking gasoline is safe for you? Plus, that **** is expensive.

[RVAbrendan]

Yes, dear god yes. Do you think leaking gasoline is safe for you? Plus, that **** is expensive.

Haha, sorry, I may have worded my question oddly. Obviously for the car to run safely and economically, I'd need to get it replaced. But, how costly are these types of repairs usually? I paid $1000 for the car and hate the idea of putting a ton into it.

[Koolblue13]

Haha, sorry, I may have worded my question oddly. Obviously for the car to run safely and economically, I'd need to get it replaced. But, how costly are these types of repairs usually? I paid $1000 for the car and hate the idea of putting a ton into it.

Swapping tanks is pretty easy. $100 ain't a bad price.

[Mr. Grundle]

2007 Chevy Trailblazer with automatic windows. The passenger window barely moves and gets stuck. I won't even attempt to roll it down anymore because I'm afraid it will get stuck down and we're now in December. Drivers side window is very slow moving and gets stuck sometimes as well. What gives?

[SpringfieldSkins]

2007 Chevy Trailblazer with automatic windows. The passenger window barely moves and gets stuck. I won't even attempt to roll it down anymore because I'm afraid it will get stuck down and we're now in December. Drivers side window is very slow moving and gets stuck sometimes as well. What gives?

My first thought is that the window motors are probably getting weak. They'll overheat and stop moving when going up. After they cool down they will go up again. Going down isn't a problem.