the problem is actually in my 2010 Panamera 4S, but I do believe the V8 was shared with the Cayenne, and since the Cayenne owners seem to be more "hands on" I was hoping someone might have some ideas of how to trouble/fix shoot this.
no white smoke, coolant levels really haven't changed much if at all, I've ordered a coolant system pressure checker, what else should I be thinking about?
if there is a leak int he system what is a good way of isolating it?
TIA
-Doug

 

Chatted with a friend, he thinks it might be the AOS.
I got my coolant pressure tester today


an hour later and it hasn't budged

I think we can say the system is tight. Ordered a new AOS