Wolpertinger

A couple of week ago I came out to find a small puddle of coolant underneath the left rear of the car, underneath where the reservoir sits. The car was cold and had sat overnight. I put the car up on the Quickjacks, and it looked like it was dripping down from a heat shield. So I pulled the wing and bumper off, and couldn't really see where it was coming from. I put a pressure tester on the system, and I didn't see any leaks, and it held pressure fine. I noticed the end of the overflow hose looked wet, and sure enough, following the trail of dried coolant it had come out of the overflow hose and dripped down. I figured a new cap would probably take care of it. So I put a new cap on, went for a great spirited drive for a good hour, came home and parked the car. No leaks that I could see. Drove it a few more times since then, all good. This morning I come out, and there's the damned puddle again! Any ideas? Coolant level is good. It's only a small puddle.

asellus

very odd, I'd expect it to pee like that as a result of heating, not cooling.

sorry, I don't have any bright ideas on this one. I assume the coolant barf tube is wet again?

boxdriver

My coolant expansion tank leaked on my 981. I had to replace it. Might be worth checking. Known issue on 981 and 991.

I found this. Have you looked here? It seems fairly common on the 991 also.
Coolant leak? - Rennlist - Porsche Discussion Forums
If this is the issue, someone posted a DIY for it.
991 Coolant Leak - DIY - Rennlist - Porsche Discussion Forums

Wolpertinger

Thanks Boxdriver. I checked that, and it's bone dry. Definitely coming from the overflow tube. It's just so strange because the system holds pressure and does not leak. It just decides to spurt coolant after shutdown. I'm due a drain and fill, so I'll go ahead and do that, and see what happens.