Dodge RAM TRUCK 1500 1995 Service Manual page 862

9 - 18 ENGINES
B R
SERVICE DIAGNOSIS—DIESEL—MECHANICAL
common
POSSIBLE CAUSES CORRECTION
LUBRICATING OIL
PRESSURE LOW
1. Low oil level.
2. Oil viscosity thin, diluted or
wrong specification.
3. Improperly operating pressure
switch/gauge.
4. Relief valve stuck open.
5. Plugged oil filter.
6. If cooler was replaced,
shipping plugs left in cooler.
7. Worn oil pump.
8. Suction tube loose or seal
leaking.
9. Loose main bearing cap.
10. Worn bearings or wrong
bearings installed.
11. Oil jet under piston bad fit into
main carrier.
1. A. Check and fill with clean engine oil
B. Check for a severe external oil leak
that could reduce the pressure.
2. Verify the correct oil is being used.
Check for oil dilution. Refer to
Contaminated Lube Oil (Engine
Diagnosis Mechanical).
3. Verify the pressure switch is functioning
correctly. If not, replace switch/gauge.
4. Check/replace valve.
5. Change oil filter. Oil filter change
interval may need to be revised.
6. Check/remove shipping plugs.
7. Check and replace oil pump.
8. Check and replace seal.
9. Check and install new bearing and
tighten cap to proper torque.
10. Inspect and replace connecting rod or
main bearings. Check and replace
piston cooling nozzles.
11. Check oil jet position.
LUBRICATING OIL
PRESSURE TOO HIGH
1. Pressure switch/gauge not
operating properly.
2. Engine running to cold.
3. Oil viscosity too thick.
4. Oil pressure relief valve stuck
closed or binding.
1. Verify the pressure switch is functioning
correctly. If not, replace switch/gauge.
2. Refer to Coolant Temperature Below
Normal (Engine Diagnosis Performance).
3. Make sure the correct oil being used,
(Refer to Group 0, Lubrication and
Maintenance).
4. Check and replace valve.
LUBRICATING OIL L O S S
1. External leaks.
2. Crankcase being overfilled.
3. Incorrect oil specification or
viscosity.
4. Oil cooler leak.
5. High blow-by forcing oil out the
breather.
8. Turbocharger leaking oil to the
air intake.
7. Piston rings not sealing (oil
being consumed by the engine).
1. Visually inspect for oil leaks. Repair as
required.
2. Verify that the correct dipstick is being used.
3. A. Make sure the correct oil is being
used.
B. Look for reduced viscosity from
dilution with fuel.
C. Review/reduce the oil change
intervals.
4. Check and replace the oil cooler.
5. Check the breather tube area for signs of
oil loss. Perform the required repairs.
6. Inspect the air ducts for evidence of oil
transfer. Repair as required.
7. Perform blow-by check. Repair as
required.
J9509-152