Humming noise from rear at starting
 

Hey guys, I'm new to Audi and the Q model line. I have a 2015 Q3. I have noticed that when I start the car, for the first 30 seconds there is a cycling humming noise that seems to be coming from the rear wheel area. Does anyone know what this might be? Thanks

Not really familiar with that model, but it could be an electronic fuel pump, or an air suspension system if you have one. Also depending on the engine type, regeneration in modern diesels can make a humming sound coming out of the exhaust.

Thanks for the input
 

Thanks for the input COLDBEER.

In fact I recently had the car at the dealer for the 5K service and mentioned it to them. They confirmed the noise, and went back and forth with Audi HQ about it. Eventually I was told that Audi HQ are aware of the problem and had just issued a TSB about replacing the fuel pump. This was performed on the car, though I still get the humming noise even after the replacement. I am planning on mentioning it again to the dealer and see what they recommend.