Well i have a 2004 3.0 quattro with the 6 speed manual trans and just recently it started to "buzz" or "zip" for a second when i shift into 3rd. The car only has 41,xxx miles on it, my thoughts are that its a syncro in the trans that is going since it doesnt occur all the time. Now is this something that switching to a heavier weight gear oil will help with or should i take it in to get things checked out and if so what costs am i looking at? i know trans work isnt cheap but would like to have some sort of ballpark of what to expect.

 

I have MT6s in both my A6 and A4. Never had a buzz in 3rd gear. I do notice that my shift into second on the A6 sometimes feels sticky and have read that synchros on this gear are the first to go. That doesn't surprise me at 156k miles, but most of the time it shifts smoothly in all gears with no unusual noises. If your synchros are failing, the symptom is rought shifting and not the noise you describe.

It could just be something vibrating at that particular combination of engine rpm and drivetrain speed. Check and make sure everything is tight under the car, especially in the exhaust system. Continue to monitor it and if it gets worse, get it checked out.

 

thanks for the input, yeah I'll check out things underneath and see if any there is any obvious culprit. But i have this feeling I'll end up taking it in to get checked out, glad i opted for an extended drivetrain warranty!