drivetrain noise

**climbernyc** · 11-24-2008 06:44 PM

driving at hwy speeds, 6MT on straight roads, when I accelerate from 2000 rpm or so, I get a loud rumble around 2500 rpm that sounds like you are running on a rumble strip on the side of the road. Any thoughts? The car is new (1300 miles) There is no steering vibration or anything like that...it feels as if it is coming from under the center of the car..

**yettavr6** · 11-24-2008 08:05 PM

i have the the SAME EXACT noise in my car. I noticed it driving home from Michigan (~ 9 hours) at 80mph or above. I didn't really pay attention to the RPM, but it's definately limited to 6th gear. I posted something on here the next day but I have yet to figure out what it is. I don't do alot of highway driving so it hasn't bothered me a whole lot yet but i definately want it fixed. Does yours pulsate in and out slowly? Mine does. My car is also fairly new (6600 miles, but it had <3000 when I noticed it).

I don't know if its related, but if i floor my car in 6th gear, even going 70mph, it feels like the engine is missing or the clutch is slipping. See if yours does that.

**Latin Audi** · 11-24-2008 09:18 PM

warranty

**urban 2.0T** · 11-25-2008 12:42 AM

I've had this problem for 35K miles and two Audi dealers have yet to fix it after 10+ trips to them (yet they acknowledge that there is a problem). For me the noise is intermittent but more often than not its there. It seems the be related to my hesitation/lack of engine responsiveness issues as well. I've given up on it and learned to live with it.

**nrosei4** · 11-25-2008 02:14 PM

Originally Posted by climbernyc

driving at hwy speeds, 6MT on straight roads, when I accelerate from 2000 rpm or so, I get a loud rumble around 2500 rpm that sounds like you are running on a rumble strip on the side of the road. Any thoughts? The car is new (1300 miles) There is no steering vibration or anything like that...it feels as if it is coming from under the center of the car..

It's difficult to tell without listening to the noise first hand, however I can offer a likely source of the sound. From what you describe, it sounds like it is gear rattle. All engines' crankshafts have pulsations. These pulsations are usually tuned out by the clutch manufacturers before they reach the transmission. As with most engineering though, there are compromises. Some vehicles will have gear rattle noise at certain RPM's and gears. Typically, the higher the gear and the higher the engine load, the worse. If it is gear rattle, there is not anything you can do about it, but it does not harm anything.

**Bmeister** · 11-25-2008 03:54 PM

If it definitely sounds like it is from the center, it is likely a problem with the center differential or the fore/aft driveshafts. If the tolerances internally are just a bit out of spec you get vibration issues especially under load.

If the vibration is only present at a specific vehicle-speed-range regardless of engine load, then it is probably an unbalanced driveshaft. This can be caused by missing balance weights (applied during manufacture), damage to the shaft itself, or if a driveshaft is not mounted properly (again, during manufacture).

Only a very experienced dealer tech will find the solution (good luck finding one of those people), so try a dedicated drivetrain/suspension shop or race car builder if the dealer keeps shrugging their shoulders at the problem.