| The Problem | Is Caused By | What To Do |
|---|---|---|
| No oil pressure | Low oil level | Add oil to correct level |
| Oil pressure gauge, warning lamp or sending unit inaccurate | Replace oil pressure gauge or warning lamp | |
| Oil pump malfunction | Replace oil pump | |
| Oil pressure relief valve sticking | Remove and inspect oil pressure relief valve assembly | |
| Oil passages on pressure side of pump obstructed | Inspect oil passages for obstruction | |
| Oil pickup screen or tube obstructed | Inspect oil pickup for obstruction | |
| Loose oil inlet tube | Tighten or seal inlet tube | |
| Low oil pressure | Low oil level | Add oil to correct level |
| Inaccurate gauge, warning lamp or sending unit | Replace oil pressure gauge or warning lamp | |
| Oil excessively thin because of dilution, poor quality, or improper grade | Drain and refill crankcase with recommended oil | |
| Excessive oil temperature | Correct cause of overheating engine | |
| Oil pressure relief spring weak or sticking | Remove and inspect oil pressure relief valve assembly | |
| Oil inlet tube and screen assembly has restriction or air leak | Remove and inspect oil inlet tube and screen assembly. (Fill inlet tube with lacquer thinner to locate leaks.) | |
| Excessive oil pump clearance | Measure clearances | |
| Excessive main, rod, or camshaft bearing clearance | Measure bearing clearances, repair as necessary | |
| High oil pressure | Improper oil viscosity | Drain and refill crankcase with correct viscosity oil |
| Oil pressure gauge or sending unit inaccurate | Replace oil pressure gauge | |
| Oil pressure relief valve sticking closed | Remove and inspect oil pressure relief valve assembly | |
| Main bearning noise | Insufficient oil supply | Inspect for low oil level and low oil pressure |
| Main bearing clearance excessive | Measure main bearing clearance, repair as necessary | |
| Bearing insert missing | Replace missing insert | |
| Crankshaft end-play excessive | Measure end-play, repair as necessary | |
| Improperly tightened main bearing cap bolts | Tighten bolts with specified torque | |
| Loose flywheel or drive plate | Tighten flywheel or drive plate attaching bolts | |
| Loose or damaged vibration damper | Repair as necessary | |