Low Oil Pressure

^ Slow idle speed.
^ Incorrect or malfunctioning oil pressure switch.
^ Incorrect or malfunctioning oil pressure gage. Replace with proper gage.
^ Improper oil viscosity or diluted oil. Install oil of proper viscosity for expected temperature, or install new oil if diluted with moisture or unburned fuel mixtures.
^ Oil pump worn or dirty.
^ Plugged oil filter.
^ Oil pickup screen loose or plugged.
^ Hole in oil pickup tube.
^ Excessive bearing clearance. Replace if necessary.
^ Cracked, porous or plugged oil galleys. Repair or replace block.
^ Galley plugs missing or incorrectly installed. Install plugs, or repair as necessary.