Thanks for the quick responses, however I have a question. I'm from the Netherlands and I have no idea what I exhaust manifold (or something) is.
is there a clear description what it is and where I can find it?
Can I check for myself if it is broken or not?
In one week I have an appointment with my dealer, I'm currently writing down all the problems I have with my CC, so far I have 3 problems:
1) roof leakage
2) right door does not close properly, it neems 'slamming'
3) humming sound at exactly 2500rpm
The last thing could be the manifold as I understand from you all.
Do you have any other suggestions?
If am going to my dealer, I want to be prepared so I can tell him what I read here and point to possible solutions.
I would be very gratefull if you can help once more
Many, many thanks in advance