surging idle

[gunsmd]

Question for anyone. I have a 2009 V8 MT6. Has anyone had a problem with a surging idle. I find that when the temperature is warm and I push the clutch in while coming to a stop the idle dips to approx 500 and surges to approx 1200 RPM prior to stabilizing at around 900-1000 RPM's. Has anyone else had this problem?? Any solutions?? Dealer says they can't duplicate the issue.

[willyjp]

Question for anyone. I have a 2009 V8 MT6. Has anyone had a problem with a surging idle. I find that when the temperature is warm and I push the clutch in while coming to a stop the idle dips to approx 500 and surges to approx 1200 RPM prior to stabilizing at around 900-1000 RPM's. Has anyone else had this problem?? Any solutions?? Dealer says they can't duplicate the issue.

Just a thought: is the clutch hanging up on dis-engagement at all? If the timing of your stop/de-clutch was such that a hang-up on disengagement was occurring, the car could be "dragging" the rpm's down briefly, followed by a little surge before stabilizing.

An "hang-up" or late disengagement COULD be caused by a worn throw out bearing, requiring a longer than normal travel to full separation of the plates.
That would be likely only if your car is fairly high miles &/or you've spent a lot of time with the clutch dis-engaged (in traffic for eg).

If such an issue IS the cause of your bouncing idle, it would ONLY be occuring on declutching as you're STOPPING. If you declutch while still rolling along at a few mph and THEN STOP, and the idle still drops/surges, then your throw out bearing would not be the cause.

If your throw out bearing is showing such wear, you might be noticing a little "notchiness" or balking of shifts when your tranny is a little cold or on the always synchro challenging 1-2 (or 2-1) shift.

Audi undoubtedly has a spec for just where, in the pedal stroke, the clutch should be fully disengaged, and I don't know what that is. But in very general terms is should be not more than about 1/3 of the way down, certainly not more than about 1/2....it varies with cars and clutches. Also, the other thing that COULD cause the clutch to hang on disengagement is a hydraulic problem in the clutch.

[KfabR8]

gun, please put your location in your profile.

Have your dealer do a throttle body re-sync. Basically the car will self diagnose and reset the mapping of the butterfly movement compared to input from the throttle.

It also may be an issue with some sort of leak in the pcv system.

Or, you've thrown a turbo system on the car and are running APR's software... if that's the case, get used to it and deal with it.

Have you done any changes such as software or an exhaust system? There have been reports of surging idle with different exhausts.

Try slipping it into neutral w/o the clutch while you coast to a stop. Does it surge here too?
Have you ever had it surge to the point of dying?

[willyjp]

Try slipping it into neutral w/o the clutch while you coast to a stop. Does it surge here too?

that says better what I was trying to say above: if the problem ONLY occurs if you de-clutch JUST as you stop, then it could be clutch related, but not if it occurs in other situations such as Kfab describes above

[gunsmd]

Thanks for all of the input. I just got my car put back together by Audi after the transmission rebuild. My clutch and throw out bearing are in perfect condition. I have not reflashed the ECU but I do have a Stasis exhaust and the EVOMS intake. My car has had the idle surge even before the mods, usually after the motor has warmed up.... I am going to bring it back to the dealer this week and take my R8 tech for a ride.....
I am located in Miami.. Have had trouble updating my profile. Sorry about that...