Hi, I have a problem and that, I had a knocking out of the engine compartment from one to the next day at the cold start, really bad. I went to the dealer where I bought it and got 10 new hydros. Then I started my engine at low outside temperature and everything was fine. On the same day in the afternoon when I wanted to drive home from the Drifftchallenge, the same clack again. As I said, only with cold engine about 2 minutes, then everything is fine again. I am stock acidic, since you have the car in the workshop ( 4 days) and then the error is still net fixed. MFG ~~~> e36c4p0