I have overhauled my car's engine. New bearings, rings, water pump, oil pump, full gasket set. After starting the car, I checked the oil pressure with a oil pressure gauge. The oil pressure was 60PSI. When revving the car slowly. the oil pressure dropped to 0 PSI. I then fitted a second new oil pump but it still does the same. What can be wrong?
Could be possible that the oil is not returning to the pan quick enough. If the pump is pushing too much oil to the top of the engine, the sump may be running dry which will drop the pressure to 0. Does the oil pressure return if you stop the engine for a minute and restart?
Maybe the bearings have too much clearance? If you did not machine the crank you may need to tear the engine down and do it over.
Gary your answer was the best. Yes after switching off the engine for a minute, the pressure is back. What could probably the problem be?
The oil returns to the pan through journals from the head to the block. I hate to say it but it may be that the head gasket was improperly installed, blocking the returns. I am not familiar with your engine but you can probably pull the valve cover and check for blocked oil return passages.
Thanks Gary. I will definitely check that.