Engine Lubrication Diagnostic Table
WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
| CONDITION | POSSIBLE CAUSES | CORRECTION |
|---|---|---|
| OIL LEAKS | 1. Misaligned or damaged gaskets and O-rings. | 1. Replace as necessary. |
| 2. Loose fasteners, broken or porous metal parts. | 2. Repair or replace metal parts. Tighten fasteners to the proper specification. Refer to TORQUE SPECIFICATIONS . | |
| 3. Crankshaft rear oil seal. | 3. Replace the rear crankshaft oil seal. Refer to REMOVAL . | |
| 4. Crankshaft rear oil seal surface scratched, nicked or grooved. | 4. Polish or replace the crankshaft. Refer to REMOVAL . | |
| 5. Oil pan flange cracked. | 5. Replace the oil pan. Refer to REMOVAL . | |
| 6. Damaged or misaligned crankshaft front oil seal. | 6. Replace the front crankshaft oil seal. Refer to REMOVAL . | |
| 7. Scratched or damaged vibration damper hub front oil seal surface. | 7. Polish or replace the vibration damper. Refer to REMOVAL . | |
| OIL PRESSURE DROP | 1. Low oil level. | 1. Check and correct the engine oil level. Refer to STANDARD PROCEDURE . |
| 2. Low oil pressure. | 2. Check the engine oil pressure. Refer to CHECKING ENGINE OIL PRESSURE . | |
| 3. Faulty oil pressure sensor. | 3. Replace the oil pressure sensor. Refer to REMOVAL . | |
| 4. Clogged oil filter. | 4. Replace the engine oil filter. Refer to REMOVAL . | |
| 5. Thin or diluted oil. | 5. Change the engine oil and filter. Refer to STANDARD PROCEDURE . | |
| 6. Worn oil pump. | 6. Replace the engine oil pump. Refer to REMOVAL . | |
| 7. Oil pump relief valve stuck. | 7. Replace the engine oil pump. Refer to REMOVAL . | |
| 8. Excessive bearing clearance. | 8. Check the crankshaft main bearing clearance. Refer to STANDARD PROCEDURE
. 8. Check the rod bearing clearance. Refer to STANDARD PROCEDURE . |
|
| OIL PUMPING AT RINGS; SPARK PLUGS FOULING | 1. Worn or damaged rings. | 1. Hone the cylinder bores and replace the piston rings. Refer to STANDARD PROCEDURE and REMOVAL . |
| 2. Carbon in oil ring slots. | 2. Replace the piston rings. Refer to REMOVAL . | |
| 3. Worn valve guides. | 3. Replace the cylinder head. Refer to REMOVAL . | |
| 4. Leaking valve guide seals. | 4. Replace the valve guide seals. Refer to REMOVAL . | |
| ENGINE OIL FILTER SWOLLEN OR BURST | 1. Obstructed or incorrect oil filter. | 1. Install new oil filter and test engine oil pressure. Refer to CHECKING ENGINE OIL PRESSURE . |
| 2. Engine oil viscosity incorrect. | 2. Change engine oil and test engine oil pressure. Refer to CHECKING ENGINE OIL PRESSURE . | |
| 3. Excessive engine oil pressure. | 3. Replace engine oil pump. Refer to REMOVAL . |