Chrysler RAM TRUCK 2500 1994 Service Manual page 728

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ENGINES 9 - 7
SERVICE DIAGNOSIS (GASOLINE ENGINES)
- MECHANICAL
CONDITION
POSSIBLE CAUSES
CORRECTION
NOISY VALVES 1. High or low oil level in
crankcase.
2. Thin or diluted oil.
3. Low oil pressure.
4. Dirt in tappets/lash adjusters.
5. Bent push rods.
6. Worn rocker arms.
7. Worn tappets/lash adjusters.
8. Worn valve guides.
9. Excessive runout of valve seats on
valve faces.
1. Check for correct oil level (refer to Group 0, Lubrication and
Maintenance).
2. Change oil (refer to Group 0, Lubrication and Maintenance).
3. Check engine oil level.
4. Clean hydraulic tappets/hydraulic lash adjusters.
5. Install new push rods.
6. Inspect oil supply to rocker arms.
7. Install new hydraulic tappets/hydraulic lash adjusters.
8. Ream and install new valves with oversize stems.
9. Grind valve seats and valves.
CONNECTING ROD
NOISE
1. Insufficient oil supply.
2. Low oil pressure.
3. Thin or diluted oil.
4. Excessive bearing clearance.
5. Connecting rod journal out-of-
round.
6. Misaligned connecting rods.
1. Check engine oil level (refer to Group 0, Lubrication and
Maintenance).
2. Check engine oil level. Inspect oil pump relief valve and spring.
3. Change oil to correct viscosity.
4. Measure bearings for correct clearance. Repair as necessary.
5. Replace crankshaft or grind journals.
6. Replace bent connecting rods.
MAIN BEARING NOISE
1. Insufficient oil supply.
2. Low oil pressure.
3. Thin or diluted oil.
4. Excessive bearing clearance.
5. Excessive end play.
6. Crankshaft journal out-of-round,
worn.
7. Loose flywheel or torque
converter.
1. Check engine oil level (refer to Group 0, Lubrication and
Maintenance).
2. Check engine oil level. Inspect oil pump relief valve and spring.
3. Change oil to correct viscosity.
4. Measure bearings for correct clearance. Repair as necessary.
5. Check No. 3 main bearing for wear on flanges.
6. Grind journals or replace crankshaft.
7. Tighten to correct torque.
OIL PRESSURE DROP 1. Low oil level.
2. Faulty oil pressure sending unit.
3. Low oil pressure.
4. Clogged oil filter.
5. Worn parts in oil pump.
6. Thin or diluted oil.
7. Excessive bearing clearance.
8. Oil pump relief valve stuck.
9. Oil pump suction tube loose, bent
or cracked.
10. Oil pump cover warped or
cracked.
1. Check engine oil level.
2. Install new sending unit.
3. Check sending unit and check main bearing oil clearance.
4. Install new oil filter.
5. Replace worn parts or pump.
6. Change oil to correct viscosity.
7. Measure bearings for correct clearance.
8. Remove valve and inspect, clean and install.
9. Remove oil pan and install new tube, if necessary.
10. Install new oil pump.
OIL LEAKS
1. Misaligned or deteriorated
gaskets.
2. Loose fastener, broken or porous
metal part.
1. Replace the gasket.
2. Tighten, repair or replace the part.
OIL PUMPING AT RINGS;
SPARK PLUGS FOULING
1. Worn, scuffed or broken rings.
2. Carbon in oil ring slot.
3. Rings fitted too tightly in grooves.
4. Worn valve guides.
5. Leaking intake gasket.
6. Leaking valve guide seals.
7. Dislodged valve guide seals.
1. Hone cylinder bores and install new rings.
2. Install new rings.
3. Remove the rings. Check grooves. If grooves are not proper
width, replace piston.
4. Ream guides and replace valves with oversize valves and seals.
5. Replace gasket and tighten intake manifold to proper torque.
6. Replace seals.
7. Seat valve guide seals or replace, as needed
J9209-58