Quote Originally Posted by Bob Parmenter View Post
Usually the first thing that pops up in this type discussion is leaking head or intake gasket, but that may not be it.

Why not get on the horn to the Prestone customer service line and play 20 questions with them?
Bob - It would really upset me if my $$$$ Fel Pro Performance level gaskets were leaking. There are no indicators - slimy/greasy coolant or milky oil nor was there any loss of either.

I put a bunch of hot water through the engine yesterday - until the flow ran clear so what I think I'll do is keep an eye on it this spring - and with the added petcocks, it's easy to dump a small amount, and if it continues, harass Prestone and/or Peak as I really don't recall which I have installed as I have jugs of both.

Also, after doing a quick Google, this is not an unusual occurrence, and much worse with GM's Dex Cool.