Heres the situation...I just went through this motor. The shortblock was untouched out of a 96 explorer without 100,000 miles (or so the guy said)...The heads are GT40ps that have been checked for cracks, surfaced and had a valve job done, and its had all new gaskets. Other than that, the only things aftermartket are the cam/springs/intake/carb...So that being said, I have not driven the car yet since the rebuild, just started it a few times...I flushed the cooling system before putting in new antifreeze, and started the car today with the cap off to burp the system, and all that came out was basically peanut butter, but Ive checked the oil dipstick and oil cap and they're clean...Any idea on what might cause this???