CONDITION POSSIBLE CAUSE CORRECTION
ENGINE MISSES ON
ACCELERATION
1. Dirty or incorrectly gapped spark
plugs.
1. Clean spark plugs and set gap. Refer
to IGNITION SYSTEM.
2. Contamination in Fuel System. 2. Clean fuel system and replace fuel
filter.
3. Burned, warped, or pitted valves. 3. Replace valves.
4. Faulty coil(s). 4. Test and replace as necessary. Refer
to IGNITION SYSTEM.
ENGINE MISSES AT HIGH
SPEED
1. Dirty or incorrect spark plug gap. 1. Clean spark plugs and set gap. Refer
to IGNITION SYSTEM.
2. Faulty coil(s). 2. Test and replace as necessary. Refer
to IGNITION SYSTEM.
3. Dirty fuel injector(s). Test and replace as necessary. Refer to
FUEL SYSTEM.
4. Contamination in fuel system. 4. Clean system and replace fuel filter.
ENGINE DIAGNOSIS—MECHANICAL
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES 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. Low oil pressure. 3. Check and correct engine oil level.
4. Dirt in tappets/lash adjusters. 4. Replace rocker arm/hydraulic lash
adjuster assembly.
5. Worn rocker arms. 5. Inspect oil supply to rocker arms.
6. Worn tappets/lash adjusters. 6. Install new rocker arm/hydraulic lash
adjuster assembly.
7. Worn valve guides. 7. Ream guides and install new valves
with oversize stems.
8. Excessive runout of valve seats on
valve faces.
8. Grind valve seats and valves.
9. Missing adjuster pivot. 9. 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. Excessive bearing clearance. 4. Measure bearings for correct
clearance. Repair as necessary.
5. Connecting rod journal out-of-round. 5. Replace crankshaft or grind surface.
6. Misaligned connecting rods. 6. Replace bent connecting rods.
9 - 84 3.2/3.5L ENGINE LH
DIAGNOSIS AND TESTING (Continued)
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