I think I am going to have a hard time describing the problem I'm having, but here it goes; while driving and going up through the gears, mostly second and third, I notice the car (99 A4 1.8TQM) kinda "stutter". I know that is kind of vague, but I don't know how else to describe it. Seems to be only when I am accelerating and I am going up in RPMs quickly that I feel this... several short hessitations, almost like it's missing. Warm or cold doesn't matter. Only notice it in second and third, probably cause I'm not in first long enough and my rate of acceleration has decresed by the time I'm in forth. Idles perfect, freely revs up without any sign of "missing".

I am not familiar with turbos that much, ( i understand how they work), and I wouldn't know what one would feel like it were damaged or going bad. I assume that the common problem would be bearings which should make some kind of noise if they are going bad, right? Is it possible for there to be something wrong with the turbo that might cause the symptom I'm trying to describe? You may be wondering why I am refering to the turbo so much... it's only cause I've never owned one before and the car has a lot of miles on it. Spark plugs could be another area for me to look in. The previous owner changed them recently but I could not figure out what they were replaced with from the receipt. It wouldn't be too expensive to start by replacing them to see if that cures the problem, but I figured I'd get some opinions here first.

TIA for any help.

Tim

It would be good place to start with the sparks if they are the wrong ones then it will cause running problems, also if they were done up with an air ratchet it could be possible that one is cracked.
The best thing to do with this problem is to visit your Audi dealer and have it looked at as they will be able to plug in the diagnostics and check for any faults in the engine managment ECU, otherwise you'll just be guessing.
If the problem is there all the time you might request to take it for drive with a mechanic as you drop it off so you can deminstrate the fault incase there are no faults stored in the ECU.

i have the same problem with my 01 S4. i have been round and round with everyone who has looked at it and replaced everything that i think it could be and it still does it. if you have a chip that would be the first thing i would check. my friend has your same exact car and he just had to have a coil pack replaced so that could be it too.

Sounds like a dual mass flywheel thats gone bad.