Have a 'newest' 2003.5 P5. (Subwoofer, no roof rack) 2100 miles. When fully warm, have an irregular idle at 1300 to 2000 RPM. Tach needle wiggles slightly, easily heard, and felt (slightly shakes car). Bonus Problem. CANNOT idle it 2100 to 2400 range. Creep up SLOWLY to 2100, and then it zooms to 3K+ on it's own. Let it creep back down to 2400, and then it drops to 1700 all on it's own. Further wierdness. It's not nearly as bad when 'half warm'. (I don't rev cold engines) Dealer sez no problem, as it idles smoothly at 700. I think Bull s**t. My old crappy 86 Golf (Bosch FI) never did that, nor does my 90 626 with 180K. Any one out there with similar experiences? Any help would be greatly appreciated.
P.S. What's the (workshop manual) spec for the 2.0 p5 oil filter relief pressure? I'm investigating oversize oil filters. Back in school (see login name) and can't afford a manual until after December.
Thanks to all.

 

I Smell a ECU reset coming on

 

CANNOT idle it 2100 to 2400 range. Creep up SLOWLY to 2100, and then it zooms to 3K+ on it's own. Let it creep back down to 2400, and then it drops to 1700 all on it's own.

===================
Mine does it too. I noticed it as I was in the driveway listening to different RPMs and the sound changed and the RPMs hiccupped slightly. although not as pronounced as your description.. It's just something in the program that changes under those condidions.

 

There is a PCM reprogramming for it. I didn't notice much of a difference when the dealer did mine but it help (a little).

 

FYI. Did the pull-the-negative-battery-cable reset trick. Not cured, but better. Will probably ask for a reset from the dealer. Thanks one and all for the feedback.