After I drainined the coolant, I noticed that there was an oily residue that is consistant with oil, not tranny fluid. My coolant resovior looked like chocolate milk, not strawberry milk. And I had the white frothy residue along the walls of the resovior.

Now, I found that since I have the factory towing option, the truck has an external and internal (Inside the radiator) tranny cooler.

Is there any where else aside from the head gasket that oil and engine coolant can come into close contact on an 03 Nav? My 98 EB Expy of course has the leaky oil cooler hose and the bad oil cooler hose gasket which has cause the chocolate milk effect (Just got the parts in, just have to install them)..