Today I have purchased a 2011 A1 with the 1.6Tdi engine. Whilst driving the car home I noticed a vibration in 5th gear when the road speed dropped to 40-45 mph. At first I assumed it was caused by a poorly balanced wheel following replacement of the offside front tyre to satisfy MOT. However changing to 4th gear there was no vibration at the above speed range. I would appreciate thoughts and maybe actions taken by another A1 owner who may have experienced the same problem before discussing with the dealer where the car was purchased.

Derrick Tridgell (New Audi Owner)

[email protected]. 

Derrick.

Where do you feel the vibration, at the steering wheel or through the seat?

Hi Cliff thanks for your reply. The vibration is felt though the seat as if the car is shaking. Derrick. 

I think we can eliminate front tyre balance. That still leaves rear tyre balance, loose wheel nuts and a host of other possibilities.

What is the engine speed when the vibration occurs in 5th gear? What happens when you drive the car in 4th gear at that same engine speed?

On reflection I re-read the question and realised you have just bought the car from a dealer, so my response changes to take the thing back and let him resolve the problem free of charge.

When it first happened I assumed that it was caused by unbalanced wheel vibration. This was in 5th gear around 40-45 mph. Changing down to 4th gear and the ride at 40-45 mph was fine. The vibration occurred again at a lower road speed. Therefore I have assumed it was caused by the engine vibrating. I have had a further thought that it maybe caused by a weak engine mounting.

I intend to go back to the dealer but I would like to have some idea what the problem might be first. 

I can't really add any thing without more information. Perhaps I did not state my questions clearly enough, so let me start again. [1] What is the engine speed, not the road speed, when the vibration occurs in 5th gear? [2] What is the engine speed, not the road speed, when the vibration occurs in 4th gear?

At both vibration periods the engine speed was less than 1500 rpm.

In that case I suspect the engine is misfiring. All the more reason to return it to the dealer without delay.

Thanks for your advise. It is an odd problem I hope the dealer can rectify it.