I have a 1995 montero SR 6G74 DOHC Engine and for about one moth I have notice that my oil pressure gauge does not mark any oil pressure (0 PSI), when the engine is hot and between idle speed and 2000 rpm; just when I speed it up to 3000 rpm it begins to mark and goes up to 60psi.
Otherwise when the engine is cold and at idle speed it marks 40psi. Is this Normal?
When the engine is cold and I start it up I have to keep my foot on the gas pedal for about five minutes and wait the engine to heat up, if not it goes off. What could be wrong?