Engine Mechanical Diagnostic Table
WARNING: This page is about a different variant/trim than selected.
| CONDITION | POSSIBLE CAUSES | CORRECTIONS |
|---|---|---|
| NOISY VALVES | 1. High or low oil level in crankcase. | 1. Adjust the engine oil level. Refer to ENGINE OIL, STANDARD PROCEDURE . |
| 2. Thin or diluted oil. | 2. Change the engine oil and filter. Refer to ENGINE OIL, STANDARD PROCEDURE . | |
| 3. Low oil pressure. | 3. Check the oil pump, if Ok, check the rod and main bearings for excessive wear. Refer to ENGINE BLOCK, STANDARD PROCEDURE . | |
| 4. Dirt in valve lash adjusters. | 4. Replace as necessary. Refer to LIFTER(S), HYDRAULIC, REMOVAL and LIFTER(S), HYDRAULIC, INSTALLATION . | |
| 5. Worn rocker arms. | 5. Replace as necessary. Refer to ROCKER ARM, VALVE, REMOVAL and ROCKER ARM, VALVE, INSTALLATION . | |
| 6. Worn valve lash adjusters. | 6. Replace as necessary. Refer to LIFTER(S), HYDRAULIC, REMOVAL and LIFTER(S), HYDRAULIC, 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, REMOVAL and CYLINDER HEAD, INSTALLATION . | |
| 8. Excessive runout of valve seats or valve faces. | 8. Replace as necessary. Refer to VALVES, INTAKE AND EXHAUST, REMOVAL and VALVES, INTAKE AND EXHAUST, INSTALLATION . | |
| CONNECTING ROD NOISE | 1. Insufficient oil supply. | 1. Check and adjust the engine oil level. Refer to ENGINE OIL, STANDARD PROCEDURE . |
| 2. Low oil pressure. | 2. Check the engine oil pump, if OK, check the rod and main bearings for excessive wear. Refer to ENGINE BLOCK, STANDARD PROCEDURE . | |
| 3. Thin or diluted oil. | 3. Change the engine oil and filter. Refer to ENGINE OIL, STANDARD PROCEDURE . | |
| 4. Excessive bearing clearance. | 4. Replace as necessary. Refer to CONNECTING ROD, STANDARD PROCEDURE . | |
| 5. Connecting rod journal out-of-round, rough surface or debris. Obstructed oil feed hole. | 5. Service or replace the crankshaft. Check the crankshaft for plugged oil feed hole. Refer to CRANKSHAFT, REMOVAL and CRANKSHAFT, INSTALLATION . | |
| 6. Misaligned connecting rods. | 6. Replace the bent connecting rods. Refer to ROD, PISTON AND CONNECTING, REMOVAL and ROD, PISTON AND CONNECTING, INSTALLATION . | |
| MAIN BEARING NOISE | 1. Insufficient oil supply. | 1. Check and adjust the engine oil level. Refer to ENGINE OIL, STANDARD PROCEDURE . |
| 2. Low oil pressure. | 2. Check the engine oil pump, if OK, check the rod and main bearings for excessive wear. Refer to ENGINE BLOCK, STANDARD PROCEDURE . | |
| 3. Thin or diluted oil. | 3. Change the engine oil and filter. Refer to ENGINE OIL, STANDARD PROCEDURE . | |
| 4. Excessive bearing clearance. | 4. Replace as necessary. Refer to BEARING(S), CRANKSHAFT, MAIN, STANDARD PROCEDURE . | |
| 5. Excessive end play. | 5. Check the thrust washers for wear. Refer to BEARING(S), CRANKSHAFT, MAIN, STANDARD PROCEDURE . | |
| 6. Crankshaft journal out of round, rough or debris. Obstructed oil feed hole. | 6. Service or replace the crankshaft. Check the engine block for plugged oil feed hole. Refer to CRANKSHAFT, REMOVAL and CRANKSHAFT, INSTALLATION . | |
| 7. Loose flexplate or torque converter. | 7. Tighten flexplate bolts to the proper torque specification. Refer to TORQUE SPECIFICATIONS . Tighten the torque converter bolts to the proper torque specification. Refer to TORQUE SPECIFICATIONS . |