I have a 2003 boxter - bought it a few months ago. kilometerage is 100,000.

today i started the vehicle and a large plume of white exhaust appeared. It cleared and did not persist after the vehicle was running. Drive to work - no problems; although check engine warning light appeared ( it is also time for service). Parked. REstarted several hours later - same result. again did not persist when car was running. drove home. parked. turned off engine. immediately restarted. same result - big white plume of exhaust which did not persist while car was running.

i have appointment with porshe service centre this week but was hoping for some clues prior to dropping the vehicle off.

can anyone suggest cause(s) of this sudden issue.

thanks