1992 Chevrolet Cavalier 3.1 L Engine Oil PressureI have replaced all the oil gaskets (valve cover, oil pan, timing cover, distbutor shaft, intake) and the timing chain and gears on this motor (motor has 142K). I'm having a problems with the oil pressure. When I start the car, oil pressure is above half on the gauge (no numbers on gauge), after the engine gets to operating temperature the oil pressure drops to nothing. I have torn it apart a couple of times and can't figure out whats wrong. I'm looking for suggestions or ideas.ThanksRik