[Wilson01S]

For starters I really hope your mechanic didn't' charge you for a timing belt replacement....as your car has 5 timing chains. Generally if you experience the same failure so close together it is something other than the part replaced. I would look hard at finding a true Porsche specialist and have them look for a cracked cylinder head, or cracked/chunked sleeve. I don't know how far he got into a tear down of the motor, but most likely your mechanic is misdiagnosing the symptoms you're experiencing as a failed head gasket when it could very much be something else. Look at some of the sticky's on the forum for common engine problems and you will see some very likely possibilities of what it could be.