Greetings all. Hope the evenings well. I recently became part of this group and am glad it is here for those of us who owns these automobiles with questions. :P

Anyways my 2.7l engine idles high (around 1100) when cold but returns to normal when the temps is near normal condition. I just got this car like a week ago and dont recall this ever on my 2001 stratus with this engine except only on really cold days and it would not idle as high or for as long.

I took off the IAC valve and inspected it. It looked ok but could be replaced I suppose. I think I might have a bad alternator as I read if the car does not get the correct volts it will idle it higher. I replaced the battery today and still high idle. Any ideas by chance?

Nick.

 

Idle speed is controlled by the engine computer acting through the idle air control valve. A vacuum leak will bypass the IAC and result in a high idle.
Take a length of tubing and search around the intake manifold and the vacuum lines leading from it while holding the other end near your ear. If you hear a hissing in one spot you have found a vacuum leak.
If there is no leak anywhere, then try replacing the IAC.

 

Hey DCotter thanx for the tip. I will have to try that tonight when I get home from work. Speaking of the intake manifold; will it too make any hissing noise that is normal?

 

Hissing indicates a leak. Leaks are not normal.

 

I was unable to locate any leaks however, I do believe it to be the IAC valve because, while the engine was running, I flicked it with my screw driver and the idles slowly ramped to normal idle. Looks like I will be replacing that after the holidays.

When I took it off to clean it I did notice some black, almost soot looking material in some spots on the IAC valve itself; as well as in the space for the IAC valve.

 

Hello.

So I got around to messing with the issue here again. Ended up replacing the IAC valve and it solved the issue. The car of course idled strange for a bit, even killed when I put it into drive but, it got used to the new part. I took it for a spin and it worked out fine. Now idles perfect as did my Stratus with the same engine.