I get a strange drone/dum on my 1.8t audi B6. Its right on the gear change around 2.5k upto 3k revs but if i select manual and hold it at those revs it will keep droning. On the other hand i dont know if its the turbo? No oil getting to the bearing, or turbo is just damaged. No droning at standstill and no drone when coasting at same revs, only when engine is under load i get the noise.