Dodge ZB 2005 Service Manual page 666

ZB
ENGINE - 8.3L (Continued)
CONDITION
ENGINE STALLS OR
ROUGH IDLE
ENGINE MISSES ON
ACCELERATION
ENGINE DIAGNOSIS - MECHANICAL
CONDITION
NOISY VALVES
POSSIBLE CAUSES
1. Carbon buildup on throttle plate.
2. Engine idle speed too low.
3. Worn or incorrectly gapped spark
plugs.
4. Faulty or crossed ignition cables.
5. Faulty coil(s).
6. Intake manifold vacuum leak.
1. Worn or incorrectly gapped spark
plugs.
2. Faulty ignition cables.
3. Dirt or water in fuel system.
4. Burned, warped, or pitted valves.
5. Faulty coil(s).
POSSIBLE CAUSES
1. High or low oil level in crank-
case.
2. Thin or diluted oil.
3. Low oil pressure.
4. Dirt in tappets/lash adjusters.
5. Bent push rod(s).
6. Worn rocker arms.
7. Worn tappets/lash adjusters.
8. Worn valve guides.
9. Excessive runout of valve seats
on valve faces.
CORRECTION
1. Remove throttle body and de-carbon.
2. Check Idle Air Control circuit. Refer to
the appropriate Diagnostic Information for
IAC motor testing.
3. Replace spark plugs or set gap.
4. Check for correct firing order or replace
ignition cables as necessary.
5. Test and replace as necessary.
6. Inspect intake manifold gasket and vac-
uum hoses. Replace as necessary.
1. Replace spark plugs or set gap.
2. Replace ignition cables as necessary.
3. Clean system and replace fuel filter.
4. Install new or reface valves as neces-
sary.
5. Test and replace as necessary.
CORRECTION
1. Check for correct oil level. Adjust oil
level by draining or adding as needed.
2. Change oil and filter.
3. Check engine oil level. If OK, perform
oil pressure test. (Refer to 9 - ENGINE/
LUBRICATION - DIAGNOSIS AND TEST-
ING).
4. Clean/replace hydraulic tappets/lash
adjusters.
5. Replace push rod(s) as necessary.
6. Replace worn rocker arms and inspect
oil supply to rocker arms.
7. Replace hydraulic tappets/hydraulic lash
adjusters.
8. Ream and install new valves with over-
size stems.
9. Grind valve seats and valves.
ENGINE 9 - 5