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 AND FILTER CHANGE .
	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 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 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 appropraite DIAGNOSIS AND TESTING .
	2. Low oil pressure.	2. Check the engine oil pump, if OK, check the rod and main bearings for excessive wear. Refer to CONNECTING ROD SIDE CLEARANCE CHECK .
	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 MEASURING BEARING CLEARANCE USING PLASTIGAGE .
	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 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 appropraite STANDARD PROCEDURE .
	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 ENGINE ASSEMBLY .
	5. Excessive end play.	5. Check the thrust washers for wear, if excessively worn replace the engine. Refer to ENGINE ASSEMBLY .
	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 or inertia ring.	7. Tighten flexplate bolts to the proper specification. Refer to TECHNICAL SPECIFICATIONS . Tighten the inertia ring bolts to the proper specification. Refer to TECHNICAL SPECIFICATIONS .