First off, I have a 2001.5 A4, 1.8T, Quattro, 5-speed, bone stock. The car has 496XX miles on it.

I was going off to run some errands when I noticed that right between 1400 and 2200 rpms, the car makes a chattering noise that gets louder as it approaches 2200 rpms. It is not specific to any gear or whether the clutch is engaged or disengaged. This was also happening the whole trip, although it was most noticeable when I was not moving. I haven't yet had a chance to check the oil level, but oil temp and coolant temp are normal. Boost seems normal as well as turbo spooling noise (I don't have a boost guage, so I can't be sure about if it is boosting normally). The display doesn't show a CEL or any other signs of a problem.

Anyone know what could be wrong? I can try and get a sound clip of the noise, but it sounds like a noisy cassette player, running a tape. I'm going to taking it to my mechanic soon for the 50k service, so it can also be checked out then.

Thanks for your help,
Cameron