| • | 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 deluded oil. |
| - | Install oil of proper viscosity for expected temperature. |
| - | 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. |
| - | Check for valve sticking in bore. |
| - | Bore scoring and burrs. |
| • | The camshaft is worn or poor machining. Replace the camshaft. |
| • | Worn valve guides. |