I have a 2000 2.7T with 85k on the clock. Full service history (just been done) and had the timing belt and water pump changed. No mods other than 18 inch wheels.

I have a problem when cruising at 80mph (5th gear, auto tranny). If I lightly back off the throttle to say 70MPH, the car starts to shudder (as though the wheels aren't balanced properly). This gets worse and becomes a judder. If I try to accelerate (without changing down gear ie accelerate gently), it gets so bad it feels as though the car will fall to bits. So, I move the gear selector across, change down to 4th, the revs rise and the judder dissappears. The car pulls strongly at any other time, speed, gear or revs. I've had the wheels checked and they're balanced correctly. No lights come on on the dash etc. It's so bad, I can't tell if it's the engine, the wheels, or some kind of voodoo!!

Any ideas, cos something is definitely not right!!

 

Just a thought. I had the auxilliary water pump replaced last month (that was NOT cheap). It was a bit of a job because of its location. Would the garage have had to slacken off any engine mounts to get at this in the 2.7T?

 

I have a tiptronic and that is common for the tiptronic to auto shift from 5th to 4th feeling throttle... That would be the biggest problem with the tiptronic of audi.. Not enough control :P Is it when you brake it shudders???

 

Start with a scan. Bad plugs will do this. You get into a lower rpm range and the the miss can be really felt, but once you downshift and increase ther rpm, the problems goes away or gets masked.

Bob

 

No it's not when I brake, just when you back off the throttle slightly. I changed the brake discs/rotors recently and I know they're fine. I think the gearbox is ok and when I shift down it's smooth.

 

I can only replicate the judder at 75-80mph in 5th (which is about 2200 revs). At that speed in any other gear or those revs in any other gear, no judder. Only 75-80mph in 5th causes it.