I have recently purchased an A3 8P 5dr 2.0 SE FSi tiptronic 2005. It replaced a 2006 1.6 SE manual.

I have noticed a strange characteristic when accelerating - when I go through 25-35mph I get a weird sensation as though the engine or gear box is wobbling side to side. This disappears again at around 35mph. Shortly after purchasing the car, I had the wheels balanced and the tracking done which eliminated some shakes I was getting when on the motorway.

I am trying to understand whether this issue is a "characteristic" of the 2.0FSi with tiptronic or whether it may be an indication of something more serious that I need to get looked at eg steering column etc.

Any pointers would be gratefully received, although if you are giving me scary scenarios please back it up with the reason for such a diagnosis - I would hate to go running back to the dealer saying that the car was falling to pieces !