Engine Mechanical Diagnostic Table
WARNING: This page is about a different car, the 2023 Jeep Grand Wagoneer L and 2023 Jeep Grand Wagoneer. However, it is still accessible from the selected car via links, so may be relevant.
| CONDITION | POSSIBLE CAUSES | CORRECTIONS |
|---|---|---|
| NOISY VALVES | 1. High or low oil level in crankcase. | 1. Adjust the engine oil level. Refer to ENGINE OIL LEVEL CHECK . |
| 2. Thin or diluted oil. | 2. Change the engine oil and filter. Refer to ENGINE OIL AND FILTER CHANGE . | |
| 3. Low oil pressure. | 3. Check the oil pump, if Ok, check the rod and main bearings for excessive wear. Refer to INSPECTION . | |
| 4. Dirt in valve lash adjusters. | 4. Replace as necessary. Refer to LIFTER(S), HYDRAULIC, REMOVAL AND INSTALLATION . | |
| 5. Worn rocker arms. | 5. Replace as necessary. Refer to ROCKER ARM, VALVE, REMOVAL AND INSTALLATION . | |
| 6. Worn valve lash adjusters. | 6. Replace as necessary. Refer to LIFTER(S), HYDRAULIC, REMOVAL AND INSTALLATION . | |
| 7. Worn valve guides. | 7. Inspect the valve guides for wear, cracks or looseness. If either condition exists, replace the cylinder head. Refer to CYLINDER HEAD ASSEMBLY, REMOVAL AND INSTALLATION . | |
| 8. Excessive runout of valve seats or valve faces. | 8. Replace as necessary. Refer to STANDARD PROCEDURE - REFACING - INTAKE AND EXHAUST VALVES . | |
| CONNECTING ROD NOISE | 1. Insufficient oil supply. | 1. Check and adjust the engine oil level. Refer to ENGINE OIL LEVEL CHECK . |
| 2. Low oil pressure. | 2. Check the engine oil pump, if OK, check the rod and main bearings for excessive wear. Refer to INSPECTION . | |
| 3. Thin or diluted oil. | 3. Change the engine oil and filter. Refer to ENGINE OIL AND FILTER CHANGE . | |
| 4. Excessive bearing clearance. | 4. Replace as necessary. Refer to STANDARD PROCEDURE . | |
| 5. Connecting rod journal out-of-round, rough surface or debris. Obstructed oil feed hole. | 5. Check the crankshaft for plugged oil feed hole repair as necessary. | |
| 6. Misaligned connecting rods. | 6. Bent connecting rods, replace the engine. | |
| MAIN BEARING NOISE | 1. Insufficient oil supply. | 1. Check and adjust the engine oil level. Refer to ENGINE OIL LEVEL CHECK . |
| 2. Low oil pressure. | 2. Check the engine oil pump, if OK, check the rod and main bearings for excessive wear. Refer to INSPECTION . | |
| 3. Thin or diluted oil. | 3. Change the engine oil and filter. Refer to ENGINE OIL AND FILTER CHANGE . | |
| 4. Excessive bearing clearance. | 4. Replace the engine. Refer to INSPECTION . | |
| 5. Excessive end play. | 5. Check the thrust washers for wear, if excessively worn replace the engine. Refer to INSPECTION . | |
| 6. Crankshaft journal out-of round, rough or debris. Obstructed oil feed hole. | 6. Check the engine block for plugged oil feed hole and repair as necessary. | |
| 7. Loose flexplate. | 7. Tighten flexplate bolts to the proper specifications. Refer to TORQUE SPECIFICATIONS . |