The only reason it came to my mind is that is a huge problem with the BMW 335i and I've been fighting with mine for months. You can generally either shim the arm and it will go away... best way to test is get a screwdriver or something metal(since its hot)and put it on the arm then rev the engine. If the noise is gone when there is pressure one the arm then that is the culprit.Janch;2070872 said:i would have never thought of this. Although as you said it i remember i changed turbo and wastegate and it happened ever since.