Matteo Trevisan

I just bought a 3 years old audi A3, I love it except that it makes a humming noise from the front of the car when running at 90km/h and 180km/h. The car by Italian law should have a limited warranty from the dealer for one year, since he is a professional used car dealer, but it seems like he has not really clue on how to fix the problem.

The dealer suggested to:
- Change Tyres (done at my expense, with no result)
- Change Front Bearings (done at his expense, with no result)

I made a video, showing also an home made spectral analysis of the noise:
The car makes the noise also when in neutral and with clutch pressed, so the generator of the noise should be between the gearbox and the tyres.
The noise has a frequency of 50Hz and 150Hz. The wheels at 90kmh rotates around 12,5Hz and at 180kmh rotates around 25Hz.

I read a very long discussion on this forum about a problem that seems really similar to mine: https://www.audiworld.com/forums/a8-...2872385/page5/

It seems that someone resolved changing or simply rotating by 180 degrees a driving shaft, someone changed the whole car.

Do you have a clue about what could generate this kind of noise?

Thank you in advance.

iampraneel

Matteo Trevisan

Faulty bearing noise isn't usually with higher pitch and audible from a certain speed up? They actually told me that they changed only one of them and solved the problem, but nothing changed actually...