Audi A3 Black Edition 2010 2.0 TDI - Making Weird Spinning Bearing Noise

[Stevo M81]

Hi everyone, i wonder if anyone has had the same problem as me. Over the last 6 months i have heard a wired noise coming from the engine bay of my Audi A3 (2010 black edition 2.0TDI 140BHP) when driving. It doesn't happen all the time and comes and goes, sometimes it won't appear for weeks then all of a sudden its back. When it happens the noise sounds like a bearing spinning round in a washing machine and it happens when pushing the accelerator and accelerating but then when i let go of the accelerator the noise slowly decreases as if the ball is losing speed and slowly coming to a stop. The most annoying thing about it is the next time i get into the car the noise will stop. So when i try and bring it to a garage they can't hear the problem.

Has anyone had the same issue. The car has 74,000 miles on it and i wonder has a part started to wear out.

Any help would be greatly appreciated

Thanks Stephen

 

[fouryoghurts]

Intermittent faults can be tricky to pin point.
If noise seems proportional to engine speed, there's a fair possibility that the noise is coming from a pulley/bearing on your auxiliary drive line.
If the fault was more predictable, I'd recommend removing the drive belt and running for a very short period.
Freewheeling alternator pulleys are common.