I have had the lower suspension arms replaced which has tigtened up the previously wooly feeling, but on a high speed run back from Oxford to Portsmouth I noticed there was still vibration at above 80. This got quite noticable at 90ish (clearly, Im making the speed up and I was actually doing 70).

It feels like its directly proportional to the ratational speed of the wheels and its amplitude modulates / comes in waves of about 2-3 seconds. I can feel it a bit through the steering wheel, but mainly feel it via the floor and seat.

Any ideas what it could be?

First thoughts would be wheel balance as the weights can easily fall off and they tend to be more noticable at higher speeds. Easy way to check is to move the rear wheels to the front and see if the problem still exists or (if the rear wheels are also out of balance!) if it changes at all.

Is it rev related of speed related?

Chris

i had that,was steering rack,but i have an octy mk 1

Look at the balance weights first. Many tyre places seem incapable of doing it right :(

Look at the balance weights first. Many tyre places seem incapable of doing it right :(

The place that fitted my last set of fronts certainly couldn't! By the time I got to Luton, my hands were numb. Fortunately, I found a tyre place that had a slot to re-do them while I waited so I didn't have to drive all the way back home with a shaky steering wheel!

I have had the lower suspension arms replaced which has tigtened up the previously wooly feeling, but on a high speed run back from Oxford to Portsmouth I noticed there was still vibration at above 80. This got quite noticable at 90ish (clearly, Im making the speed up and I was actually doing 70).

It feels like its directly proportional to the ratational speed of the wheels and its amplitude modulates / comes in waves of about 2-3 seconds. I can feel it a bit through the steering wheel, but mainly feel it via the floor and seat.

Any ideas what it could be?

How old/what mileage are your tyres?

I've had a sensation like this, though years ago and not in a VAG car (it was a Ford). Whenever I've had front wheel imbalance it's always come in at a lower speed than you're experiencing and been possible to drive through it.

The symptoms I had were very, very similar to those you describe - worse at higher speeds (70-90, I mean approaching 70 officer;)), proportional to road speed, felt through the car rather than just the steering and coming and going in waves every few seconds. I discovered this was due to the delamination of the rear offside tyre. Think that's the right description - anyway, the tread was starting to come off, although plenty of tread depth still there! Changed the cheap tyres for something decent and problem magically cured.

Had a similar problem recently................got my tyres re-balanced and that sorted it as they were way out...............