When I am driving around at low speeds and I shift into neutral (such as coming to a stop at a light) my engine races a little and my tach jumps up to 2000-2200 RPMs for a couple seconds before it finally settles back down to a normal idle RPM. It has been doing this for about 2 days. Any suggestions/ideas?

 

Try cleaning out the IAC.

Just curious. Are you auto or manual?

 

Mine was sticking off idle, so I took off the whole TB and cleaned it. It's easy to take off if you have done the coolant bypass. Mine had so much carbon in it, cleaning cured all of the problem.

John

 

It's a 1996 M6 w/ 33k. I had the TB off about 8k ago when I changed the intake manifold gasket. I didn't have any cleaner at the time, but it was fairly dirty. So, I just cleaned around the blades w/ a shop rag. Maybe it's time to take it off and spray it w/ some cleaner.

 

when i had an M6 my car did that too. some people said it was just normal on an m6....just a thought, maybe somebody else with an m6 will reply. mine is not drivable, a tree hit my car!...and boy do i miss the m6.

i just realized you said it revs to 2000rpm...that can't be normal. mine would just go up to like 1200-1300rpm...it probably just needs cleaned, check your vacuum lines too.

Michael

 

Have you done any PCM programming lately? It almost sounds like you put a PCM file from an A4 into an M6.

On the other hand, M6 cars still do have something called a "Throttle follower offset vs. MPH" which is meant to keep vacuum for braking and stuff while the car is moving. A4 cars just have it noticibly more... While you are stopped will it do it? If it does it while you are stopped it is probably a sticky IAC valve.