Hello All!! Can anyone help me with my problem on my audi A4? After driving for a while, I park my car and leave it in idle and there is a loud moaning/humm noise which comes from the area around my air intake. Can anyone tell me how to fix this?

Thanks in advance.

 

I have the same issue. The dealers don't even know what it is. The car has to be running for a while before it happens. and it happend between 1k and 2k rpm. a low humming noise. It can happen at idle too. Any one have a clue what this might be? Its coming from the engine or under the engine.

 

I think i hear the high pitch noise coming from the DV (circular little chrome cylinder with a flat top behind the engine at the top near the bottom the windshield) A plastic circular thing that looks like it goes into another hose with three pipes goes into the engine. Is it likely that the DV is keeping the noise?

HELP

 

the Diverter value wouldnt be making that noise. sounds like your car is adjusting when its idling and vibrating at a different frequency, one that makes something else in your car vibrate