The oil light also the temperature gauge comes on and goes off. on 1997 Ford Expedition

there's no sign of coolant spill on the ground no sign of white smoke coming out of the tailpipe. I was told to just change my reservoir tank. The vehicle drives for almost in half hour then the oil light and the temperature light comes on. No sign of a blown head gasket

Asked by for the 1997 Ford Expedition
have manual oil pressure test performed and also have cooling system temp verified b4 you ruin an engine.