Audi a3 2.0tdi bkd engine if i blip the throtle it sounds like a loose washer rattling around slightly when the revs come back down. The noise seems be be coming from the rear of the engine bay. The turbo has been replaced but the noise is still there. May just be normal but i dont have another car to check. Could it be the vnt in the turbo that vibrates abit as when i split my old turbo its not held down firmly!?