Engine Mechanical Diagnostic Table
WARNING: This page is about a different car, the 2020 Jeep Renegade. 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 FILTER, ENGINE OIL, REMOVAL AND INSTALLATION . |
| 2. Thin or diluted oil. | 2. Change the engine oil and filter. Refer to FILTER, ENGINE OIL, REMOVAL AND INSTALLATION . | |
| 3. Low oil pressure. | 3. Check the oil pump, if Ok, check the rod and main bearings for excessive wear. Refer to MEASURING BEARING CLEARANCE USING PLASTIGAGE . | |
| 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, REMOVAL AND INSTALLATION . | |
| 8. Excessive runout of valve seats or valve faces. | 8. Replace as necessary. Refer to REFACING - INTAKE AND EXHAUST VALVES . | |
| CONNECTING ROD NOISE | 1. Insufficient oil supply. | 1. Check and adjust the engine oil level. Refer to FILTER, ENGINE OIL, REMOVAL AND INSTALLATION . |
| 2. Low oil pressure. | 2. Check the engine oil pump, if OK, check the rod and main bearings for excessive wear. Refer to MEASURING BEARING CLEARANCE USING PLASTIGAGE . | |
| 3. Thin or diluted oil. | 3. Change the engine oil and filter. Refer to FILTER, ENGINE OIL, REMOVAL AND INSTALLATION . | |
| 4. Excessive bearing clearance. | 4. Replace as necessary. Refer to BEARING(S), 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 INSTALLATION . | |
| 6. Misaligned connecting rods. | 6. Replace the bent connecting rods. Refer to ROD, PISTON AND CONNECTING, REMOVAL AND INSTALLATION . | |
| MAIN BEARING NOISE | 1. Insufficient oil supply. | 1. Check and adjust the engine oil level. Refer to FILTER, ENGINE OIL, REMOVAL AND INSTALLATION . |
| 2. Low oil pressure. | 2. Check the engine oil pump, if OK, check the rod and main bearings for excessive wear. Refer to MEASURING BEARING CLEARANCE USING PLASTIGAGE . | |
| 3. Thin or diluted oil. | 3. Change the engine oil and filter. Refer to FILTER, ENGINE OIL, REMOVAL AND INSTALLATION . | |
| 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 CRANKSHAFT END PLAY . | |
| 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 INSTALLATION . | |
| 7. Loose flywheel, flexplate or torque converter. | 7. Tighten the bolts to the proper specification. Refer to TORQUE SPECIFICATIONS . |