| VALVETRAIN NOISE |
1. High or low oil level in crankcase. |
1. Check and correct engine oil level. |
| 2. Thin or diluted oil. |
2. Change oil to correct viscosity. |
| 3. Thick oil |
3. (a) Change engine oil and filter. |
| - |
(b) Run engine to operating temperature. |
| - |
(c) Change engine oil and filter again. |
| 4. Low oil pressure. |
4. Check and correct engine oil level. |
| 5. Dirt in lash adjusters. |
5. Replace rocker arm/hydraulic lash adjuster assembly. |
| 6. Worn rocker arms. |
6. Inspect oil supply to rocker arms. |
| 7. Worn lash adjusters. |
7. Install new rocker arm/hydraulic lash adjuster assembly. |
| 8. Worn valve guides. |
8. Ream guides and install new valves with oversize stems. |
| 9. Excessive runout of valve seats on valve faces. |
9. Grind valve seats and valves. |
| 10. Missing adjuster pivot. |
10. Replace rocker arm/hydraulic lash adjuster assembly. |
| CONNECTING ROD NOISE |
1. Insufficient oil supply. |
1. Check engine oil level. |
| 2. Low oil pressure. |
2. Check engine oil level. Inspect oil pump relief valve and spring. |
| 3. Thin or diluted oil. |
3. Change oil to correct viscosity. |
| 4. Thick oil |
4. (a) Change engine oil and filter. |
| - |
(b) Run engine to operating temperature. |
| - |
(c) Change engine oil and filter again. |
| 5. Excessive bearing clearance. |
5. Measure bearings for correct clearance. Repair as necessary. |
| 6. Connecting rod journal out-of-round. |
6. Replace crankshaft or grind surface. |
| 7. Misaligned connecting rods. |
7. Replace bent connecting rods. |
| MAIN BEARING NOISE |
1. Insufficient oil supply. |
1. Check engine oil level. |
| 2. Low oil pressure. |
2. Check engine oil level. Inspect oil pump relief valve and spring. |
| 3. Thin or diluted oil. |
3. Change oil to correct viscosity. |
| 4. Thick oil |
4. (a) Change engine oil and filter. |
| - |
(b) Run engine to operating temperature. |
| - |
(c) Change engine oil and filter again. |
| 5. Excessive bearing clearance. |
5. Measure bearings for correct clearance. Repair as necessary. |
| 6. Excessive end play. |
6. Check thrust bearing for wear on flanges. |
| 7. Crankshaft journal out-of-round or worn. |
7. Replace crankshaft or grind journals. |
| 8. Loose flywheel or torque converter. |
8. Tighten to correct torque. |
| OIL PRESSURE DROP |
1. Low oil level. |
1. Check engine oil level. |
| 2. Faulty oil pressure sending unit. |
2. Install new sending unit. |
| 3. Low oil pressure. |
3. Check sending unit and main bearing oil clearance. |
| 4. Clogged oil filter. |
4. Install new oil filter. |
| 5. Worn parts in oil pump. |
5. Replace worn parts or pump. |
| 6. Thin or diluted oil. |
6. Change oil to correct viscosity. |
| 7. Oil pump relief valve stuck. |
7. Remove valve and inspect, clean, or replace. |
| 8. Oil pump suction tube loose. |
8. Remove oil pan and install new tube or clean, if necessary. |
| 9. Oil pump cover warped or cracked. |
9. Install new oil pump. |
| 10. Excessive bearing clearance. |
10. Measure bearings for correct clearance. |
| OIL LEAKS |
1. Misaligned or deteriorated gaskets. |
1. Replace gasket(s). |
| 2. Loose fastener, broken or porous metal part. |
2. Tighten, repair or replace the part. |
| 3. Misaligned or deteriorated cup or threaded plug. |
3. Replace as necessary. |
| OIL CONSUMPTION OR SPARK PLUGS FOULED |
1. PCV system malfunction. |
1. Check system and repair as necessary. (Refer to EMISSIONS CONTROL/EVAPORATIVE EMISSIONS/PCV VALVE - DIAGNOSIS AND TESTING) |
| 2. Worn, scuffed or broken rings. |
2. Hone cylinder bores. Install new rings. |
| 3. Carbon in oil ring slots. |
3. Install new rings. |
| 4. Rings fitted too tightly in grooves. |
4. Remove rings and check grooves. If groove is not proper width, replace piston. |
| 5. Worn valve guide(s). |
5. Ream guide(s) and replace valve(s) with oversize valve(s) and seal(s). |
| 6. Valve stem seal(s) worn or damaged. |
6. Replace seal(s). |