Originally Posted by msheredy

I think what you are experiencing is the supercharger clutch engaging. Do you sometimes hear a slight chirp too? Many E55 and some SLK/C32 owners experience this. I too experience it. You can read through my experience here. Here is a thread from an MB forum where they are saying that if you are experiencing a rough engagement that the clutch needs to be replaced. Now that I have found out this info I want to take mine back in and tell them what I have found.

On my thread only the 1st and last page really explain what I was experiencing and the outcome.