oil viscosity DODGE RAM 2003 Service Repair Manual

Diesel fuel is seldom completely free of water. To
prevent fuel system trouble, including fuel line freez-
ing in winter, drain the accumulated water from the
fuel/water separator using the fuel/water separator
drain provided. If you buy good-quality fuel and fol-
low the cold-weather advice above, fuel conditioners
should not be required in your vehicle. If available in
your area, a high cetane ªpremiumº diesel fuel may
offer improved cold starting and warm-up perfor-
mance.
DESCRIPTION - ENGINE OIL AND LUBRICANTS
WARNING: NEW OR USED ENGINE OIL CAN BE
IRRITATING TO THE SKIN. AVOID PROLONGED OR
REPEATED SKIN CONTACT WITH ENGINE OIL.
CONTAMINANTS IN USED ENGINE OIL, CAUSED BY
INTERNAL COMBUSTION, CAN BE HAZARDOUS TO
YOUR HEALTH. THOROUGHLY WASH EXPOSED
SKIN WITH SOAP AND WATER. DO NOT WASH
SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR
SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO
NOT POLLUTE, DISPOSE OF USED ENGINE OIL
PROPERLY. CONTACT YOUR DEALER OR GOVERN-
MENT AGENCY FOR LOCATION OF COLLECTION
CENTER IN YOUR AREA.
When service is required, DaimlerChrysler Corpo-
ration recommends that only Mopartbrand parts,
lubricants and chemicals be used. Mopartprovides
the best engineered products for servicing
DaimlerChrysler Corporation vehicles.
Only lubricants bearing designations defined by
the following organization should be used.
²Society of Automotive Engineers (SAE)
²American Petroleum Institute (API)
²National Lubricating Grease Institute (NLGI)
API SERVICE GRADE CERTIFIED
Use an engine oil that is API Certified. MOPARt
provides engine oils, that meet or exceed this
requirement.
SAE VISCOSITY
An SAE viscosity grade is used to specify the vis-
cosity of engine oil. Use only engine oils with multi-
ple viscosities such as 5W-30 or 10W-30. These are
specified with a dual SAE viscosity grade which indi-
cates the cold-to-hot temperature viscosity range.
Select an engine oil that is best suited to your par-
ticular temperature range and variation (Fig. 2).
ENERGY CONSERVING OIL
An Energy Conserving type oil is recommended for
gasoline engines. The designation of ENERGY CON-
SERVING is located on the label of an engine oil con-
tainer.
CONTAINER IDENTIFICATION
Standard engine oil identification notations have
been adopted to aid in the proper selection of engine
oil. The identifying notations are located on the front
label of engine oil plastic bottles and the top of
engine oil cans (Fig. 3).
This symbol means that the oil has been certified
by the American Petroleum Institute (API). Diamler-
Chrysler only recommend API Certified engine oils.
Use Mopartengine oil or equivalent.
GEAR LUBRICANTS
SAE ratings also apply to multigrade gear lubri-
cants. In addition, API classification defines the
lubricants usage. Such as API GL-5 and SAE 75W-
90.
LUBRICANTS AND GREASES
Lubricating grease is rated for quality and usage
by the NLGI. All approved products have the NLGI
symbol (Fig. 4) on the label. At the bottom of the
NLGI symbol is the usage and quality identification
letters. Wheel bearing lubricant is identified by the
letter ªGº. Chassis lubricant is identified by the letter
ªLº. The letter following the usage letter indicates
the quality of the lubricant. The following symbols
indicate the highest quality.
Fig. 2 TEMPERATURE/ENGINE OIL VISCOSITY
Fig. 3 API SYMBOL
0 - 2 LUBRICATION & MAINTENANCEDR
FLUID TYPES (Continued)

FLUID ADDITIVES
DaimlerChrysler strongly recommends against the
addition of any fluids to the transmission, other than
those automatic transmission fluids listed above.
Exceptions to this policy are the use of special dyes
to aid in detecting fluid leaks.
Various ªspecialº additives and supplements exist
that claim to improve shift feel and/or quality. These
additives and others also claim to improve converter
clutch operation and inhibit overheating, oxidation,
varnish, and sludge. These claims have not been sup-
ported to the satisfaction of DaimlerChrysler and
these additivesmust not be used.The use of trans-
mission ªsealersº should also be avoided, since they
may adversely affect the integrity of transmission
seals.
OPERATION - AUTOMATIC TRANSMISSION
FLUID
The automatic transmission fluid is selected based
upon several qualities. The fluid must provide a high
level of protection for the internal components by
providing a lubricating film between adjacent metal
components. The fluid must also be thermally stable
so that it can maintain a consistent viscosity through
a large temperature range. If the viscosity stays con-
stant through the temperature range of operation,
transmission operation and shift feel will remain con-
sistent. Transmission fluid must also be a good con-
ductor of heat. The fluid must absorb heat from the
internal transmission components and transfer that
heat to the transmission case.
FLUID CAPACITIES
SPECIFICATIONS
FLUID CAPACITIES
2DESCRIPTIONSPECIFICATION
FUEL TANK
Short Box (Lt. Duty) 98 L (26 gal.)*
Long Box (Lt. Duty) 132 L (35 gal.)*
ENGINE OIL WITH FILTER
3.7L 4.7 L (5.0 qts.)
4.7L 5.6 L (6.0 qts.)
5.7L 6.6 L (7.0 qts.)
5.9L 4.7 L (5.0 qts.)
8.0L 6.6 L (7.0 qts.)
5.9L DIESEL 10.4 L (11.0 qts.)
2DESCRIPTION SPECIFICATION
COOLING SYSTEM
3.7L 15.4 L (16.2 qts.)**
4.7L 15.4 L (16.2 qts.)**
5.7L 15.4L (16.2 qts.)**
5.9L 15.5 L (16.3 qts.)**
8.0L 24L (24.3 qts.)**
5.9L Diesel Engine 28L (29.5 qts.)**
POWER STEERING
Power steering fluid capacities are dependent on engine/
chassis options as well as steering gear/cooler options.
Depending on type and size of internal cooler, length and
inside diameter of cooler lines, or use of an auxiliary cooler,
these capacities may vary. Refer to 19, Steering for proper
fill and bleed procedures.
AUTOMATIC TRANSMISSION
Service Fill - 46RE 3.8 L (4.0 qts.)
O-haul - 46RE 9-9.5L (19-20 pts.)L
Service Fill - 45RFE/
545RFE4X2 - 5.2 L (11.0 pts.)
4X4 - 6.2 L (13.0 pts.)
O-haul - 45RFE/545RFE 14-16 L (29-33 pts.)L
LDry fill capacity Depending on type and size of internal
cooler, length and inside diameter of cooler lines, or use of
an auxiliary cooler, these figures may vary. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC/FLUID -
STANDARD PROCEDURE)
MANUAL TRANSMISSION
NV3500 4X2 2.3 L (4.8 pts.)
NV3500 4X4 2.0 L (4.2 pts.)
NV4500 3.8 L (8.0 pts.)
NV5600 4.5 L (9.5 pts.)
TRANSFER CASE
NV241 GENII 1.6 L (3.4 pts.)
NV243 1.6 L (3.4 pts.)
NV271 1.89 L (4.0 pts.)
NV273 1.89 L (4.0 pts.)
FRONT AXLE   .03 L (1 oz)
C205F 1.66 L (3.5 pts.)
9 1/4 AA 2.25 L (4.75 pts.)
REAR AXLE   .03 L (1 oz)
9 1/4 2.32 L (4.9 pts.)***
10 1/2 AA 2.25 L (4.75 pts.)
11 1/2 AA 3.62 L (7.65 pts)
*** With Trac-Lok add 118 ml (4 oz.) of Limited Slip Additive.
** Includes 0.9L (1.0 qts.) for coolant reservoir.
*Nominal refill capacities are shown. A variation may be
observed from vehicle to vehicle due to manufacturing
tolerance and refill procedure.
DRLUBRICATION & MAINTENANCE 0 - 5
FLUID TYPES (Continued)

NOTE: Make sure filter gasket was removed with fil-
ter.
(5) With a wiping cloth, clean the gasket sealing
surface of oil and grime.
INSTALLATION
(1) Lightly lubricate oil filter gasket with engine
oil.
(2) Thread filter onto adapter nipple. When gasket
makes contact with sealing surface, (Fig. 85) hand
tighten filter one full turn, do not over tighten.
(3) Add oil, verify crankcase oil level and start
engine. Inspect for oil leaks.
OIL
STANDARD PROCEDURE - ENGINE OIL
SERVICE
WARNING: NEW OR USED ENGINE OIL CAN BE
IRRITATING TO THE SKIN. AVOID PROLONGED OR
REPEATED SKIN CONTACT WITH ENGINE OIL.
CONTAMINANTS IN USED ENGINE OIL, CAUSED BY
INTERNAL COMBUSTION, CAN BE HAZARDOUS TO
YOUR HEALTH. THOROUGHLY WASH EXPOSED
SKIN WITH SOAP AND WATER. DO NOT WASH
SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR
SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO
NOT POLLUTE, DISPOSE OF USED ENGINE OIL
PROPERLY.
ENGINE OIL SPECIFICATION
CAUTION: Do not use non-detergent or straight
mineral oil when adding or changing crankcase
lubricant. Engine failure can result.
API SERVICE GRADE CERTIFIED
Use an engine oil that is API Service Grade Certi-
fied. MOPARtprovides engine oils that conform to
this service grade.
SAE VISCOSITY
An SAE viscosity grade is used to specify the vis-
cosity of engine oil. Use only engine oils with multi-
ple viscosities such as 5W-30 or 10W-30 in the 4.7L
engines. These are specified with a dual SAE viscos-
ity grade which indicates the cold-to-hot temperature
viscosity range. Select an engine oil that is best
suited to your particular temperature range and vari-
ation (Fig. 86).
ENERGY CONSERVING OIL
An Energy Conserving type oil is recommended for
gasoline engines. The designation of ENERGY CON-
SERVING is located on the label of an engine oil con-
tainer.
CONTAINER IDENTIFICATION
Standard engine oil identification notations have
been adopted to aid in the proper selection of engine
oil. The identifying notations are located on the label
of engine oil plastic bottles and the top of engine oil
cans (Fig. 87).
Fig. 85 Oil Filter Sealing Surface-Typical
1 - SEALING SURFACE
2 - RUBBER GASKET
3 - OIL FILTERFig. 86 TEMPERATURE/ENGINE OIL VISCOSITY -
4.7L ENGINE
Fig. 87 Engine oil Container Standard Notations
9 - 70 ENGINE - 3.7LDR
OIL FILTER (Continued)

camshaft bore cup plugs oil galley pipe plugs, oil
filter runoff, and main bearing cap to cylinder
block mating surfaces.
(4) If no leaks are detected, pressurize the crank-
case as outlined in the, Inspection (Engine oil Leaks
in general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is
detected between the crankshaft and seal while
slowly turning the crankshaft, it is possible the
crankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled.
OIL
STANDARD PROCEDURE - ENGINE OIL
SERVICE
WARNING: NEW OR USED ENGINE OIL CAN BE
IRRITATING TO THE SKIN. AVOID PROLONGED OR
REPEATED SKIN CONTACT WITH ENGINE OIL.
CONTAMINANTS IN USED ENGINE OIL, CAUSED BY
INTERNAL COMBUSTION, CAN BE HAZARDOUS TO
YOUR HEALTH. THOROUGHLY WASH EXPOSED
SKIN WITH SOAP AND WATER. DO NOT WASH
SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR
SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO
NOT POLLUTE, DISPOSE OF USED ENGINE OIL
PROPERLY.
ENGINE OIL SPECIFICATION
CAUTION: Do not use non-detergent or straight
mineral oil when adding or changing crankcase
lubricant. Engine failure can result.
API SERVICE GRADE CERTIFIED
Use an engine oil that is API Service Grade Certi-
fied. MOPARtprovides engine oils that conform to
this service grade.
SAE VISCOSITY
An SAE viscosity grade is used to specify the vis-
cosity of engine oil. Use only engine oils with multi-
ple viscosities such as 5W-30 or 10W-30 in the 4.7L
engines. These are specified with a dual SAE viscos-
ity grade which indicates the cold-to-hot temperature
viscosity range. Select an engine oil that is best
suited to your particular temperature range and vari-
ation (Fig. 94).
ENERGY CONSERVING OIL
An Energy Conserving type oil is recommended for
gasoline engines. The designation of ENERGY CON-
SERVING is located on the label of an engine oil con-
tainer.
CONTAINER IDENTIFICATION
Standard engine oil identification notations have
been adopted to aid in the proper selection of engine
oil. The identifying notations are located on the label
of engine oil plastic bottles and the top of engine oil
cans (Fig. 95).
OIL LEVEL INDICATOR (DIPSTICK)
The engine oil level indicator is located at the right
rear of the engine on the 4.7L engines. (Fig. 96).
CRANKCASE OIL LEVEL INSPECTION
CAUTION: Do not overfill crankcase with engine oil,
pressure loss or oil foaming can result.
Fig. 94 TEMPERATURE/ENGINE OIL VISCOSITY -
4.7L ENGINE
Fig. 95 Engine oil Container Standard Notations
DRENGINE - 4.7L 9 - 151
LUBRICATION (Continued)

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - MECHANICAL
ENGINE MECHANICAL DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES/LIFTERS 1. High or low oil level in crankcase 1. Check for correct oil level. Adjust
oil level by draining or adding as
needed
2. Thin or diluted oil 2. Change oil. (Refer to 9 - ENGINE/
LUBRICATION/OIL - STANDARD
PROCEDURE)
3. Low oil pressure 3. Check engine oil level. If ok,
Perform oil pressure test. (Refer to 9 -
ENGINE/LUBRICATION -
DIAGNOSIS AND TESTING) for
engine oil pressure test/specifications
4. Dirt in tappets/lash adjusters 4. Clean/replace hydraulic tappets/
lash adjusters
5. Bent push rod(s) 5. Install new push rods
6. Worn rocker arms 6. Inspect oil supply to rocker arms
and replace worn arms as needed
7. Worn tappets/lash adjusters 7. Install new hydraulic tappets/lash
adjusters
8. Worn valve guides 8. Inspect all valve guides and
replace as necessary
9. Excessive runout of valve seats or
valve faces9. Grind valves and seats
CONNECTING ROD NOISE 1. Insufficient oil supply 1. Check engine oil level.
2. Low oil pressure 2. Check engine oil level. If ok,
Perform oil pressure test. (Refer to 9 -
ENGINE/LUBRICATION -
DIAGNOSIS AND TESTING) engine
oil pressure test/specifications
3. Thin or diluted oil 3. Change oil to correct viscosity.
(Refer to 9 - ENGINE/LUBRICATION/
OIL - STANDARD PROCEDURE) for
correct procedure/engine oil
specifications
4. Excessive connecting rod bearing
clearance4. Measure bearings for correct
clearance with plasti-gage. Repair as
necessary
5. Connecting rod journal out of
round5. Replace crankshaft or grind
journals
6. Misaligned connecting rods 6. Replace bent connecting rods
MAIN BEARING NOISE 1. Insufficient oil supply 1. Check engine oil level.
2. Low oil pressure 2. Check engine oil level. If ok,
Perform oil pressure test. (Refer to 9 -
ENGINE/LUBRICATION -
DIAGNOSIS AND TESTING)
3. Thin or diluted oil 3. Change oil to correct viscosity.
9 - 184 ENGINE - 5.7LDR
ENGINE - 5.7L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
4. Excessive main bearing clearance 4. Measure bearings for correct
clearance. Repair as necessary
5. Excessive end play 5. Check crankshaft thrust bearing for
excessive wear on flanges
6. Crankshaft main journal out of
round or worn6. Grind journals or replace crankshaft
7. Loose flywheel or torque converter 7. Inspect crankshaft, flexplate/
flywheel and bolts for damage.
Tighten to correct torque
LOW OIL PRESSURE 1. Low oil level 1. Check oil level and fill if necessary
2. Faulty oil pressure sending unit 2. Install new sending unit
3. Clogged oil filter 3. Install new oil filter
4. Worn oil pump 4. Replace oil pump assembly.
5. Thin or diluted oil 5. Change oil to correct viscosity.
6. Excessive bearing clearance 6. Measure bearings for correct
clearance
7. Oil pump relief valve stuck 7. Remove valve to inspect, clean and
reinstall
8. Oil pickup tube loose, broken, bent
or clogged8. Inspect oil pickup tube and pump,
and clean or replace if necessary
9. Oil pump cover warped or cracked 9. Install new oil pump
OIL LEAKS 1. Misaligned or deteriorated gaskets 1. Replace gasket
2. Loose fastener, broken or porous
metal part2. Tighten, repair or replace the part
3. Front or rear crankshaft oil seal
leaking3. Replace seal
4. Leaking oil gallery plug or cup plug 4. Remove and reseal threaded plug.
Replace cup style plug
EXCESSIVE OIL CONSUMPTION OR
SPARK PLUGS OIL FOULED1. CCV System malfunction 1. (Refer to 25 - EMISSIONS
CONTROL/EVAPORATIVE
EMISSIONS - DESCRIPTION) for
correct operation
2. Defective valve stem seal(s) 2. Repair or replace seal(s)
3. Worn or broken piston rings 3. Hone cylinder bores. Install new
rings
4. Scuffed pistons/cylinder walls 4. Hone cylinder bores and replace
pistons as required
5. Carbon in oil control ring groove 5. Remove rings and de-carbon piston
6. Worn valve guides 6. Inspect/replace valve guides as
necessary
7. Piston rings fitted too tightly in
grooves7. Remove rings and check ring end
gap and side clearance. Replace if
necessary
DRENGINE - 5.7L 9 - 185
ENGINE - 5.7L (Continued)

ENGINE OIL SPECIFICATION
CAUTION: Do not use non-detergent or straight
mineral oil when adding or changing crankcase
lubricant. Engine failure can result.
API SERVICE GRADE CERTIFIED
Use an engine oil that is API Service Grade Certi-
fied. MOPARtprovides engine oils that conform to
this service grade.
SAE VISCOSITY
An SAE viscosity grade is used to specify the vis-
cosity of engine oil. Use only engine oils with multi-
ple viscosities such as 5W-30 in the 5.7L engines.
These are specified with a dual SAE viscosity grade
which indicates the cold-to-hot temperature viscosity
range. Select an engine oil that is best suited to your
particular temperature range and variation.
ENERGY CONSERVING OIL
An Energy Conserving type oil is recommended for
gasoline engines. The designation of ENERGY CON-
SERVING is located on the label of an engine oil con-
tainer.
CONTAINER IDENTIFICATION
Standard engine oil identification notations have
been adopted to aid in the proper selection of engine
oil. The identifying notations are located on the label
of engine oil plastic bottles and the top of engine oil
cans (Fig. 26).
OIL LEVEL INDICATOR (DIPSTICK)
The engine oil level indicator is located at the left
hand of the engine on the 5.7L engines.
CRANKCASE OIL LEVEL INSPECTION
CAUTION: Do not overfill crankcase with engine oil,
pressure loss or oil foaming can result.
Inspect engine oil level approximately every 800
kilometers (500 miles). Unless the engine has exhib-
ited loss of oil pressure, run the engine for about tenminutes before checking oil level. Checking engine oil
level on a cold engine is not accurate.
To ensure proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
The acceptable levels are indicated between the ADD
and SAFE marks on the engine oil dipstick.
(1) Position vehicle on level surface.
(2) With engine OFF, allow approximately five
minutes for oil to settle to bottom of crankcase,
remove engine oil dipstick.
(3) Wipe dipstick clean.
(4) Install dipstick and verify it is seated in the
tube.
(5) Remove dipstick, with handle held above the
tip, take oil level reading.
(6) Add oil only if level is below the ADD mark on
dipstick.
ENGINE OIL CHANGE
Change engine oil at mileage and time intervals
described in Maintenance Schedules(Refer to LUBRI-
CATION & MAINTENANCE/MAINTENANCE
SCHEDULES - DESCRIPTION).
Run engine until achieving normal operating tem-
perature.
(1) Position the vehicle on a level surface and turn
engine off.
(2) Hoist and support vehicle on safety stands.
(3) Remove oil fill cap.
(4) Place a suitable drain pan under crankcase
drain.
(5) Remove drain plug from crankcase and allow
oil to drain into pan. Inspect drain plug threads for
stretching or other damage. Replace drain plug if
damaged.
(6) Install drain plug in crankcase. Torque to 34
N´m ( 25 ft. lbs.).
(7) Lower vehicle and fill crankcase with specified
type and amount of engine oil described in this sec-
tion.
(8) Install oil fill cap.
(9) Start engine and inspect for leaks.
(10) Stop engine and inspect oil level.
USED ENGINE OIL DISPOSAL
Care should be exercised when disposing used
engine oil after it has been drained from a vehicle
engine. Refer to the WARNING at beginning of this
section.
OIL FILTER
REMOVAL
All engines are equipped with a high quality full-
flow, disposable type oil filter. DaimlerChrysler Cor-
Fig. 26 API SYMBOL
9 - 216 ENGINE - 5.7LDR
OIL (Continued)

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - MECHANICAL
ENGINE MECHANICAL DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES/LIFTERS 1. High or low oil level in crankcase 1. Check for correct oil level. Adjust
oil level by draining or adding as
needed
2. Thin or diluted oil 2. Change oil. (Refer to 9 - ENGINE/
LUBRICATION/OIL - STANDARD
PROCEDURE)
3. Low oil pressure 3. Check engine oil level. If ok,
Perform oil pressure test. (Refer to 9 -
ENGINE/LUBRICATION -
DIAGNOSIS AND TESTING) for
engine oil pressure test/specifications
4. Dirt in tappets/lash adjusters 4. Clean/replace hydraulic tappets/
lash adjusters
5. Bent push rod(s) 5. Install new push rods
6. Worn rocker arms 6. Inspect oil supply to rocker arms
and replace worn arms as needed
7. Worn tappets/lash adjusters 7. Install new hydraulic tappets/lash
adjusters
8. Worn valve guides 8. Inspect all valve guides and
replace as necessary
9. Excessive runout of valve seats or
valve faces9. Grind valves and seats
CONNECTING ROD NOISE 1. Insufficient oil supply 1. Check engine oil level.
2. Low oil pressure 2. Check engine oil level. If ok,
Perform oil pressure test. (Refer to 9 -
ENGINE/LUBRICATION -
DIAGNOSIS AND TESTING) engine
oil pressure test/specifications
3. Thin or diluted oil 3. Change oil to correct viscosity.
(Refer to 9 - ENGINE/LUBRICATION/
OIL - STANDARD PROCEDURE) for
correct procedure/engine oil
specifications
4. Excessive connecting rod bearing
clearance4. Measure bearings for correct
clearance with plasti-gage. Repair as
necessary
5. Connecting rod journal out of
round5. Replace crankshaft or grind
journals
6. Misaligned connecting rods 6. Replace bent connecting rods
MAIN BEARING NOISE 1. Insufficient oil supply 1. Check engine oil level.
2. Low oil pressure 2. Check engine oil level. If ok,
Perform oil pressure test. (Refer to 9 -
ENGINE/LUBRICATION -
DIAGNOSIS AND TESTING)
3. Thin or diluted oil 3. Change oil to correct viscosity.
9 - 228 ENGINE - 5.9LDR
ENGINE - 5.9L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
4. Excessive main bearing clearance 4. Measure bearings for correct
clearance. Repair as necessary
5. Excessive end play 5. Check crankshaft thrust bearing for
excessive wear on flanges
6. Crankshaft main journal out of
round or worn6. Grind journals or replace crankshaft
7. Loose flywheel or torque converter 7. Inspect crankshaft, flexplate/
flywheel and bolts for damage.
Tighten to correct torque
LOW OIL PRESSURE 1. Low oil level 1. Check oil level and fill if necessary
2. Faulty oil pressure sending unit 2. Install new sending unit
3. Clogged oil filter 3. Install new oil filter
4. Worn oil pump 4. Replace oil pump assembly.
5. Thin or diluted oil 5. Change oil to correct viscosity.
6. Excessive bearing clearance 6. Measure bearings for correct
clearance
7. Oil pump relief valve stuck 7. Remove valve to inspect, clean and
reinstall
8. Oil pickup tube loose, broken, bent
or clogged8. Inspect oil pickup tube and pump,
and clean or replace if necessary
9. Oil pump cover warped or cracked 9. Install new oil pump
OIL LEAKS 1. Misaligned or deteriorated gaskets 1. Replace gasket
2. Loose fastener, broken or porous
metal part2. Tighten, repair or replace the part
3. Front or rear crankshaft oil seal
leaking3. Replace seal
4. Leaking oil gallery plug or cup plug 4. Remove and reseal threaded plug.
Replace cup style plug
EXCESSIVE OIL CONSUMPTION OR
SPARK PLUGS OIL FOULED1. CCV System malfunction 1. (Refer to 25 - EMISSIONS
CONTROL/EVAPORATIVE
EMISSIONS - DESCRIPTION) for
correct operation
2. Defective valve stem seal(s) 2. Repair or replace seal(s)
3. Worn or broken piston rings 3. Hone cylinder bores. Install new
rings
4. Scuffed pistons/cylinder walls 4. Hone cylinder bores and replace
pistons as required
5. Carbon in oil control ring groove 5. Remove rings and de-carbon piston
6. Worn valve guides 6. Inspect/replace valve guides as
necessary
7. Piston rings fitted too tightly in
grooves7. Remove rings and check ring end
gap and side clearance. Replace if
necessary
DRENGINE - 5.9L 9 - 229
ENGINE - 5.9L (Continued)

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐENGINE DIAGNOSIS - MECHANICAL
CONDITION POSSIBLE CAUSES CORRECTION
LUBRICATING OIL
PRESSURE LOW1. Low oil level. 1. (a) Check and fill with clean engine oil.
(b) Check for a severe external oil leak that
could reduce the pressure.
2. Oil viscosity thin, diluted or wrong
specification.2. (a) Verify the correct engine oil is being
used. (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
2. (b) Look for reduced viscosity from fuel
dilution.
3. Improperly operating pressure
switch/gauge.3. Verify the pressure switch is functioning
correctly. If not, replace switch/gauge.
4. Relief valve stuck open. 4. Check/replace valve.
6. If cooler was replaced, shipping
plugs may have been left in cooler6. Check/remove shipping plugs.
7. Worn oil pump. 7. Check and replace oil pump.
8. Suction tube loose or seal leaking. 8. Check and replace seal.
9. Loose main bearing cap. 9. Check and install new bearing. Tighten
cap to proper torque.
10. Worn bearings or wrong bearings
installed.10. Inspect and replace connecting rod or
main bearings. Check and replace directed
piston cooling nozzles.
11. Directed piston cooling nozzles
under piston, bad fit into main
carrier.11. Check directed piston cooling nozzles
position.
12. Loose oil rifle plug with saddle-jet
style nozzles12.Tighten oil rifle plug.
13. Loose directed piston cooling
nozzle.13. Tighten directed piston cooling nozzle.
14. Both J-jet and saddle jet style
cooling nozzle installed.14. Install correct style jet.
LUBRICATING OIL
PRESSURE TOO HIGH1. Pressure switch/gauge not
operating properly.1. Verify pressure switch is functioning
correctly. If not, replace switch/gauge.
2. Engine running too cold. 2. Refer to Coolant Temperature Below
Normal (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
3. Oil viscosity too thick. 3. Make sure the correct oil is being used.
(Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
4. Oil pressure relief valve stuck
closed or binding4. Check and replace valve.
DRENGINE 5.9L DIESEL 9 - 283
ENGINE 5.9L DIESEL (Continued)