Engine Question
 

Okay so when I first bought the car it was smooth, could barely hear the engine. Now it's loud and noise and has a pretty rough idle, sometimes shaking the car. I don't know what exactly is wrong with it but either way mechanics are crazy expensive and I've been reading every spare chance I get to learn more about how car engine's work, etc. because I want to work on the car myself when I discover what the problem is.

I'm not going to be doing anything until summer but I'll be doing a lot of research before then so I'm asking you guys for links or advice or anything that will help me understand and be able to work on my own car.

I'd also appreciate any feedback on what you think has caused this noisy, rough engine issue. Would I have to rebuild the engine or something?

Re: Engine Question
 

does the check engine light ever come on? If so, you could check the codes...
Keith

Re: Engine Question
 

check all of the hoses going into the TB and intake. You could have a vacuum leak.
-Bill

Re: Engine Question
 

Could you describe the noise? And where it seems to be eminating from? That would be a big help.

Re: Engine Question
 

It came on awhile ago and flashed but then it went away. It comes on every now and again but goes off after a few minutes.

I don't exactly know what that means.

If I remember correctly it's too loud to figure out where it's coming from but I'll pop the hood tonight and have another look.

Re: Engine Question
 

Okay so the noise is coming from the front, left side of the engine. I can't get much more specific than that.

Re: Engine Question
 

I'll be more specific;):D

There are numerous vacuum lines that attach to fittings on the intake manifold (they tend to be ~1/8 to 1/4 inch diameter black rubber lines). Over time, they become brittle from the heat and exposure to the various fumes floating around the engine compartment. This leads to cracks that cause vacuum leaks, which means the sensor that is depending on seeing variations in vacuum will not function correctly. There just happens to be such a line right behind the alternator that feeds vacuum info to the IRIS valve ;) This line also has a check valve that has been know to crack and cause a vacuum leak (you won't know unless you actually remove the valve, as it is between two pieces of vacuum line)

There are also lines that are part of the PCV system that go from ports on the engine back to the "snorkus" (the black, hard plastic air intake that goes from the MAF back to the Throttle Body (TB). They can also get brittle with age and leak, dumping air into the system after the MAF has already sent an "air flow" signal to the ECU (thus throwing the A/F mixture off).

Last possibility is that one of the gaskets between the fuel injector stand offs and the engine and intake manifold is leaking. This can also cause a "air leak" into the system.

Good look tracking things down.

-Bill