I have a 99" A4 Avant Automatic... Recently I've noticed a pretty rough vibration during hard acceleration. It feels like it's directly under my seat, right in the middle of the car. It quickly goes away at about 15 miles an hour. Now like I said it's only under hard acceleration, I can drive around normal and never feel it. I did just have new tires put on, but as far as I know they're perfectly balanced. And the vibration isn't there any other time. Although the do howl like a banshee, they're snow tires. If anyone could help me I would greatly appreciate it. I'm not dumb when it comes to cars, but audi's are new to me...


Thanks

 

Try rotating the tires from front to rear and see if the vibration goes from your seat to the steering wheel.
That will tell you if your tires are bad.

 

I have the same problem, i was think it was mechanical since it only happens when i slam it into 4th and gas it, let me know if you find out what it is.

 

I've been having the same problem with my 99 A4 1.8T, i took it to a mechanic today for diagnostic, it turned out to be one of the cylinders was missfiring or missdetected

 

I had a similar vibration...45 MPH to 70 MPH...only under acceleration.

Turned out to be a worn CV joint. Had it and driveshaft replaced at the dealership.

Smooth as silk now...