Has your coolant level been going down at all?

With hind sight, I realized my car had some of this "foam" on the dip stick and in the flame trap as well. My car was taking about 1pt of coolant every 2 weeks and I could see some coolant on the rear cross support under the back of the engine. I had the system pressure tested at the dealer and they found the external leakage between the head and block on the back passenger side corner. Once I had the head off, from the leakage path, I realized there was probably some coolant leaking into the oil as well. For some reason the gasket just seemed to have deteriated in that corner. The head and block were fine. I had the head pressure tested, valves vacuum checked and a skim cut done to ensure a good surface for the new gasket.

If your coolant level is stable, it is probably just condensation. If you want to ease your mind you could have an oil analysis done. "Google" for Oil Analysis and you should find a couple places to have it done for say $20.00 or less.

Keep us posted.
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'96 965, 16' wheels, rear 18mm bar & Koni + 204HP cams at 122K. Had '85 745 Turbo Diesel for 200K.