- Low engine oil level
- Problem with the engine oil pressure gauge
- Contaminated engine oil
- Improper circulation of the engine oil
- Worn components
Check the engine oil level. The engine oil level can possibly be too far below the suction tube for the engine oil pump. The engine oil pump cannot supply enough lubrication to the engine components. If the engine oil level is low add engine oil in order to obtain the correct level. For the correct engine oil to use, refer to Operation and Maintenance Manual, "Engine Oil".
If the engine oil pressure gauge is incorrect, install a new gauge. Refer to Testing and Adjusting, "Engine Oil Pressure - Test".
Engine oil that is contaminated with another liquid will cause low engine oil pressure. High engine oil level can be an indication of contamination. Determine the reason for contamination of the engine oil and make the necessary repairs. Change the engine oil and the engine oil filter. For the correct engine oil to use, refer to Operation and Maintenance Manual, "Engine Oil".
Improper Circulation of the Engine Oil
Several factors could cause improper circulation of the engine oil:
- The engine oil filter is clogged. Replace the engine oil filter.
- A line or a passage for the engine oil is disconnected or broken.
- The engine oil cooler is clogged. Thoroughly clean the engine oil cooler.
- There is a problem with a piston cooling jet. The piston cooling jets direct engine oil toward the bottom of the pistons in order to cool the pistons. This also provides lubrication for the piston pin. Breakage, a restriction, or incorrect installation of a piston cooling jet will cause seizure of the piston.
- The inlet screen of the suction tube for the engine oil pump can have a restriction. This restriction will cause cavitation and a loss of engine oil pressure. Check the inlet screen on the suction tube and remove any material that may be restricting engine oil flow.
- The suction tube is drawing in air. Check the joints of the suction tube for cracks or a damaged O-ring seal.
- There is a problem with the engine oil pump. Check the gears of the engine oil pump for excessive wear. Engine oil pressure is reduced by gears in the engine oil pump that have too much wear.
Excessive clearance at the crankshaft or camshaft bearings will cause low engine oil pressure. Also, inspect the clearance between the rocker arm shafts and the rocker arms. Check the engine components for excessive clearance.