My 2002 C4 cabriolet (2nd gen 996 if that matters), has a coolant leak that doesn't dump any liquid, just smells like coolant. I replaced the cap (had a -00 cap). Because of the superceded cap, I was sure I had licked the problem. When I removed the old cap, it was about 5 hours after running the car and there was a release of pressure. After next drive cycle, it pushed a little coolant out, apparently down an overfill tube. It landed on / near the left exhaust tip. So much for history, now the question: Does an 02 C4 have a favorite part(s) that fails, releasing coolant vapor but not liquid coolant? Should I check the cap to make sure I didn't just get a new but equally as bad cap? I wish the svc manual CD had a schematic of the cooling system. One more quickie.... Svc manual says "nothing but Porsche brand coolant". Are they serious? Do I really have to drive a 75 minute round trip for 4 ounces of coolant or can I use something locally?

 

I bet your coolant tank is cracked. Happens now and again.

 

Thanks Doc. Is there any hoses / clamps, etc. I should replace while R&Ring the tank (assuming it is the tank of course)?