Yeah this thread is old.
So did you figure it out? I put my money down on lower intake and or head gasket.
Felpro makes a pretty serious gasket set, 100 bucks. Ive put two of them on different vehicles, never had any problems. Update on myself, I no longer use dexcool at all period end of story. Prestone is a dex clone. same stuff. I just bought the walmart junk 8 dollars a gal. Why? It had two less ingredients than dexcool. not sure if those two ingredients help or hurt
. The key with these engines, is to not let air get into the coolant system, and dont let the coolant get old. Keep it fresh and your good. Toyota also uses dexcool FYI.