Low or No Oil Pressure

^ Low oil level. Fill to the full mark on the oil level indicator.
^ Slow idle speed.
^ Incorrect or malfunctioning oil pressure switch. Replace it with a proper switch.
^ Incorrect or malfunctioning oil pressure gauge. Replace it with a proper gauge.
^ Improper oil viscosity or diluted oil
a. Install oil of proper viscosity for expected temperature.
b. Install new oil if it is diluted with moisture or unburned fuel mixture.
^ The oil pump is worn or dirty. Clean or replace the pump.
^ The oil filter is plugged. Replace the filter.
^ The oil pickup screen is loose or plugged. Tighten or replace the screen.
^ A hole in the oil pickup tube. Replace the pickup tube.
^ Excessive bearing clearance. Replace if necessary.
^ Cracked, porous, or plugged oil galleries. Repair or replace the block
^ The gallery plugs are missing or improperly installed. Install or repair as necessary.
^ The pressure regulator valve is stuck.
a. Check for valve sticking in bore.
b. Check the bore for scoring and burrs.
^ The camshaft is worn or poor machining. Replace the camshaft.
^ Worn valve guides.