Oss DODGE RAM 2003 Service Repair Manual

INSPECTION
Mating surface of the oil pump cover should be
smooth. Replace pump cover if scratched or grooved.
Lay a straightedge across the pump cover surface
(Fig. 58). If a 0.076 mm (0.003 inch) feeler gauge can
be inserted between cover and straightedge, cover
should be replaced.
Measure thickness (Fig. 59) (Fig. 60) and diameter
of rotors. If either rotor thickness measures 14.956mm (0.5876 inch) or less, or if the diameter is 82.45
mm (3.246 inches) or less, replace rotor set.
Slide outer rotor into timing chain cover pump
body. Press rotor to the side with your fingers and
measure clearance between rotor and pump body
(Fig. 61). If clearance is 0.19 mm (0.007 inch) or
more, and outer rotor is within specifications, replace
timing chain cover.
Install inner rotor into timing chain cover pump
body (Fig. 62). Inner rotor should be positioned with
chamfer up or toward engine when cover is installed.
This allows easy installation over crankshaft. If
clearance between inner and outer rotors is 0.150
mm (0.006 inch) or more, replace both rotors.
Place a straightedge across the face of the timing
chain cover pump body, between bolt holes (Fig. 63).
If a feeler gauge of 0.077 mm (0.003 inch) or more
can be inserted between rotors and the straightedge,
and the rotors are within specifications, replace tim-
ing chain cover.
Fig. 57 Oil Pump
1 - OUTER ROTOR
2 - INNER ROTOR
3 - OIL PUMP COVER
4 - TIMING CHAIN COVER
Fig. 58 Checking Oil Pump Cover Flatness
1 - FEELER GAUGE
2 - STRAIGHT EDGE
3 - OIL PUMP COVER
Fig. 59 Measuring Outer Rotor Thickness
Fig. 60 Measuring Inner Rotor Thickness
DRENGINE 8.0L 9 - 399
OIL PUMP (Continued)

Inspect oil pressure relief valve plunger for scoring
and free operation in its bore. Small marks may be
removed with 400-grit wet or dry sandpaper.
The relief valve spring has a free length of approx-
imately 49.5 mm (1.95 inches). The spring should
test between 100 and 109 N (22.5 and 24.5 pounds)
when compressed to 34 mm (1-11/32 inches). Replace
spring that fails to meet these specifications.
If oil pressure was low and pump is within specifi-
cations, inspect for worn engine bearings or other
reasons for oil pressure loss.
INSTALLATION
(1) Lubricate both oil pump rotors using petroleum
jelly or lubriplate and install in the timing chain
cover. Use new parts as required (Fig. 64).(2) Position the oil pump cover onto the timing
chain cover. Tighten cover screws to 14 N´m (125 in.
lbs.) torque.
(3) Make sure that inner ring moves freely after
cover is installed.
(4) Install the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
(5) Squirt oil into relief valve hole until oil runs
out.
(6) Install the relief valve and spring.
Fig. 61 Measuring Outer Rotor Clearance in Cover
1 - FEELER GAUGE
2 - OUTER ROTOR
Fig. 62 Measuring Inner Rotor Clearance in Cover
1 - FEELER GAUGE
2 - OUTER ROTOR
3 - INNER ROTOR
Fig. 63 Measuring Clearance Over Rotors
1 - FEELER GAUGE
2 - STRAIGHT EDGE
Fig. 64 Priming Oil Pump.
1 - FILL WITH PETROLEUM JELLY OR LUBER PLATE
9 - 400 ENGINE 8.0LDR
OIL PUMP (Continued)

(7) Using a new pressure relief valve gasket,
install the relief valve plug. Tighten the plug to 20
N´m (15 ft. lbs.) torque.
(8) Install oil filter that has been filled with oil.
INTAKE MANIFOLD
DESCRIPTION
The aluminum intake manifold (Fig. 65) has two
plenum chambers an upper and lower which supply
air to five runners each. Passages across the longitu-
dinal center of the manifold feed air from the throttle
body to the plenum chambers.
DIAGNOSIS AND TESTINGÐINTAKE
MANIFOLD LEAKAGE
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS, OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
(2) Spray a small stream of water at the suspected
leak area.(3) If a change in RPMs occur, the area of the sus-
pected leak has been found.
(4) Repair as required.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(3) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(4) Remove the generator brace and generator
(Fig. 66).
(5) Remove the A/C compressor brace (Fig. 66).
Remove the compressor and set aside.
(6) Remove the air cleaner cover and filter.
Remove the air cleaner housing (Fig. 67). Discard the
gasket.
(7) Perform the Fuel System Pressure release pro-
cedure (Refer to 14 - FUEL SYSTEM/FUEL DELIV-
ERY - STANDARD PROCEDURE). Disconnect the
fuel lines (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY/QUICK CONNECT FITTING - STAN-
DARD PROCEDURE).
(8) Disconnect the accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.
(9) Remove the coil assemblies with the ignition
wires.
(10) Disconnect the vacuum lines.
(11) Disconnect the heater hoses and bypass hose.
(12) Remove the closed crankcase ventilation and
evaporation control systems.
Fig. 65 Upper and Lower Intake ManifoldÐ8.0L
Engine
1 - UPPER INTAKE MANIFOLD
2 - THROTTLE BODY (MPI)
3 - LOWER INTAKE MANIFOLD
Fig. 66 Generator and A/C Compressor Braces
1 - GENERATOR
2 - INTAKE MANIFOLD TO GENERATOR BRACE
3 - A/C COMPRESSOR
4 - INTAKE MANIFOLD TO A/C COMPRESSOR BRACE
DRENGINE 8.0L 9 - 401
OIL PUMP (Continued)

(13) Remove the throttle body bolts and lift the
throttle body off the upper intake manifold (Fig. 68).
Discard the gasket.
(14) Remove upper intake manifold bolts.
(15) Lift the upper intake manifold out of the
engine compartment (Fig. 68). Discard the gasket.
(16) Remove the lower intake manifold bolts and
remove the manifold (Fig. 69).
(17) Discard the lower intake manifold gaskets
(Fig. 70).
CLEANING
Clean manifold in solvent and blow dry with com-
pressed air.
Clean cylinder block gasket surfaces using a suit-
able solvent.The plenum pan rail must be clean and dry (free of
all foreign material).
INSPECTION
Inspect manifold for cracks.
Inspect mating surfaces of manifold for flatness
with a straightedge.
INSTALLATION
(1) Install the intake manifold side gaskets. Be
sure that the locator dowels are positioned in the
head (Fig. 71).
Fig. 67 Air Intake Housing
1 - AIR INTAKE HOUSING
Fig. 68 Upper Intake Manifold and Throttle Body
1 - UPPER INTAKE MANIFOLD
2 - THROTTLE BODY (MPI)
3 - LOWER INTAKE MANIFOLD
Fig. 69 Lower Intake Manifold
Fig. 70 Lower Intake Manifold Gaskets
1 - INTAKE MANIFOLD GASKET
2 - SEALANT
3 - CROSS-OVER GASKETS
4 - SEALANT
5 - LOCATOR DOWELS
9 - 402 ENGINE 8.0LDR
INTAKE MANIFOLD (Continued)

(2) Insert MopartGEN II Silicone Rubber Adhe-
sive Sealant, or equivalent, into the four corner joints
an excessive amount of sealant is not required to
ensure a leak proof seal. However, an excessive
amount of sealant may reduce the effectiveness of
the flange gasket. The sealant should be approxi-
mately 5 mm (0.2 in.) in diameter. (Fig. 70).
(3) Position the cross-over gaskets and press firmly
onto the block (Fig. 70).BE SURE THE BLOCK IS
OIL FREE..
(4) The lower intake manifold MUST be installed
within 3 minutes of sealant application. Carefully
lower intake manifold into position on the cylinder
block and heads. After intake manifold is in place,
inspect to make sure seals and gaskets are in place.
Finger start all the lower intake bolts.
(5) Tighten the lower intake manifold bolts in
sequence to 54 N´m (40 ft. lbs.) torque (Fig. 69).
Recheck all bolts are tightened to 54 N´m (40 ft. lbs.)
torque.
(6) Using a new gasket, position the upper intake
manifold onto the lower intake manifold.
(7) Finger start all bolts, alternate one side to the
other.
(8) Tighten upper intake manifold bolts in
sequence to 22 N´m (16 ft. lbs.) torque (Fig. 68).
(9) Using a new gasket, install the throttle body
onto the upper intake manifold. Tighten the bolts to
23 N´m (200 in. lbs.) torque.
(10) Install closed crankcase ventilation and evap-
oration control systems.
(11) Connect the heater hoses and bypass hose.
(12) Connect the vacuum lines.
(13) Install the coil assemblies and the ignition
wires.
(14) Connect the accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.(15) Install the fuel lines (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE).
(16) Using a new gasket, install the air cleaner
housing. Tighten the nuts to 11 N´m (96 in. lbs.)
torque. Install the air cleaner filter and cover.
(17) Install the A/C compressor (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - INSTALLATION). Position the com-
pressor brace and install the bolts. Tighten the brace
bolts to 41 N´m (30 ft. lbs.) torque.
(18) Install the generator (Refer to 8 - ELECTRI-
CAL/CHARGING/GENERATOR - INSTALLATION).
Position the generator brace and install the bolts.
Tighten the brace bolts to 41 N´m (30 ft. lbs.) torque.
(19) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(20) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(21) Connect the negative cable to the battery.
(22) Start engine check for leaks.
EXHAUST MANIFOLD
DESCRIPTION
Engine exhaust manifolds (Fig. 72) are made of
high molybdenum ductile cast iron. A special ribbed
design helps control permanent dimensional changes
during heat cycles.
OPERATION
The exhaust manifolds collect the engine exhaust
exiting the combustion chambers, then channels the
exhaust gases to the exhaust pipes attached to the
manifolds.
Fig. 71 Intake Manifold Flange
1 - LOCATOR DOWELS
2 - INTAKE MANIFOLD GASKETS
3 - LOCATOR DOWELS
Fig. 72 Exhaust ManifoldÐ8.0L Engine
1 - EXHAUST MANIFOLD
DRENGINE 8.0L 9 - 403
INTAKE MANIFOLD (Continued)

DESCRIPTION ± 5.9L DIESEL
CAUTION: Avoid application of rust prevention com-
pounds or undercoating materials to exhaust sys-
tem floor pan exhaust heat shields. Light overspray
near the edges is permitted. Application of coating
will result in excessive floor pan temperatures and
objectionable fumes.
The diesel engine exhaust system consists of an
engine exhaust manifold, turbocharger, exhaust pipe,resonator, extension pipe (if needed), muffler and
exhaust tailpipe.
California emission vehicales include a catalytic
converter.
The exhaust system must be properly aligned to
prevent stress, leakage and body contact. The
exhaust components should be kept a minimum of
25.4 mm (1.0 in.) away from the body and frame. If
the system contacts any body panel, it may amplify
objectionable noises from the engine or body.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - GAS ENGINE
EXHAUST SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSE CORRECTION
EXCESSIVE EXHAUST NOISE OR
LEAKING EXHAUST GASES1. Leaks at pipe joints. 1. Tighten clamps/bolts at leaking
joints.
2. Rusted or blown out muffler. 2. Replace muffler. Inspect exhaust
system.
3. Broken or rusted out exhaust
pipe.3. Replace exhaust pipe.
4. Exhaust pipe leaking at manifold
flange.4. Tighten/replace flange attaching
nuts/bolts.
5. Exhaust manifold cracked or
broken.5. Replace exhaust manifold.
6. Leak between exhaust manifold
and cylinder head.6. Tighten exhaust manifold to
cylinder head bolts.
7. Catalytic converter rusted or
blown out.7. Replace catalytic converter assy.
8. Restriction in exhaust system. 8. Remove restriction, if possible.
Replace restricted part if necessary.
CAUTION:
When servicing and replacing exhaust system components, disconnect the oxygen sensor connector(s). Allowing
the exhaust to hang by the oxygen sensor wires will damage the harness and/or sensor.
11 - 2 EXHAUST SYSTEMDR
EXHAUST SYSTEM (Continued)

DIAGNOSIS AND TESTING - DIESEL ENGINE
EXHAUST SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSE CORRECTION
EXCESSIVE EXHAUST NOISE OR
LEAKING EXHAUST GASES1. Leaks at pipe joints. 1. Tighten clamps/bolts at leaking
joints.
2. Rusted or blown out muffler. 2. Replace muffler. Inspect exhaust
system.
3. Broken or rusted out exhaust
pipe.3. Replace exhaust pipe.
4. Exhaust pipe leaking at manifold
flange.4. Tighten/replace flange attaching
nuts/bolts.
5. Exhaust manifold cracked or
broken.5. Replace exhaust manifold.
6. Leak between exhaust manifold
and cylinder head.6. Tighten exhaust manifold to
cylinder head bolts. Replace gasket
if necessary.
7. Turbocharger mounting flange
cracked.7. Remove turbocharger and
inspect. (Refer to 11 - EXHAUST
SYSTEM/TURBOCHARGER
SYSTEM/TURBOCHARGER -
REMOVAL).
8. Restriction in exhaust system. 8. Remove restriction, if possible.
Replace restricted part if necessary.
DREXHAUST SYSTEM 11 - 3
EXHAUST SYSTEM (Continued)

REMOVAL
REMOVAL
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINES.
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove the bolts from the crossover pipe to the
catalytic converter connection.
(4) Disconnect oxygen sensor wiring.
(5) Loosen the nuts from the clamp that hold the
catalytic converter to the exhaust pipe flange connec-
tion.
NOTE: Do not remove nut from T-Bolt. Only remove
nut far enough, so that the T end can be removed
from the clamp.
(6) Remove the T bolt end of the fastener, from the
clamp.
(7) Spread the clamp, and remove the catalytic
converter from the vehicle.
(8) Discard the clamp.
NOTE: The catalytic converter to exhaust manifold
clamp is not reusable. Always use a new clamp
when reinstalling the catalytic converter.
REMOVAL
(1) Raise and support vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove clamps and nuts.
(4) Remove the catalytic converter.
INSPECTION
Look at the stainless steel body of the converter,
inspect for bulging or other distortion that could be a
result of overheating. If the converter has a heat
shield attached make sure it is not bent or loose.
If you suspect internal damage to the catalyst, tap-
ping the bottom of the catalyst with a rubber mallet
may indicate a damaged core.
INSTALLATION
INSTALLATION
NOTE: The catalytic converter to exhaust manifold
clamp is not reusable. Always use a new clamp
when reinstalling the catalytic converter.(1) Position the catalytic converter onto the
exhaust pipe flange connection. Tighten the nuts to
28 N´m (250 in. lbs.) torque.
(2) Install the muffler onto the catalytic converter
until the alignment tab is inserted into the align-
ment slot.
(3) Install the exhaust clamp at the muffler and
catalytic converter connection. Tighten the clamp
nuts to 47 N´m (35 ft. lbs.) torque.
(4) Connect oxygen sensor wiring.
(5) Lower the vehicle.
(6) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels.
Adjust the alignment, if needed.
INSTALLATION
(1) Assemble converter and clamps loosely in
place.
(2) Install the exhaust pipe onto exhaust mani-
folds, tighten 31 N´m (23 ft. lbs.).
(3) Tighten all clamp nuts to 48 N´m (35 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels. A
minimum of 25.4 mm (1.0 in.) is required between
exhaust system components and body/frame parts.
Adjust the alignment, if needed.
EXHAUST PIPE
REMOVAL
REMOVAL Ð 5.9L
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove exhaust pipe to manifold bolts, retain-
ers and nuts.
(4) Remove the clamp nuts.
(5) Remove the exhaust pipe (Fig. 1).
REMOVAL
CAUTION: When servicing or replacing exhaust
system components, disconnect the oxygen sensor
connector(s). Allowing the exhaust to hang by the
oxygen sensor wires will damage the harness
and/or sensor.
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with MopartRust
Penetrant. Allow 5 minutes for penetration.
(3) Disconnect the oxygen sensor(s).
DREXHAUST SYSTEM 11 - 5
CATALYTIC CONVERTER (Continued)

(4) Remove the exhaust manifold-to-exhaust pipe
nuts (Fig. 2).
(5) Remove exhaust pipe to converter exhaust
clamp.
(6) Disconnect the exhaust pipe from the catalytic
converter front flange.
(7) Remove the exhaust pipe.
INSPECTION
Discard rusted clamps, broken or worn supports
and attaching parts. Replace a component with orig-
inal equipment parts, or equivalent. This will assure
proper alignment with other parts in the system and
provide acceptable exhaust noise levels.
INSTALLATION
INSTALLATION Ð 5.9L
(1) Position the exhaust pipe for proper clearance
with the frame and underbody parts. A minimum
clearance of 25.4 mm (1.0 in.) is required.
(2) Position the exhaust pipe to manifold. Install
the bolts, retainers and nuts. Tighten the nuts to 31
N´m (23 ft. lbs.) torque.
(3) Tighten the clamp nuts to 48 N´m (35 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels.
Adjust the alignment, if needed (Fig. 1) and (Fig. 3).
Fig. 1 Exhaust Pipe to Manifold Connection ± 5.9L
1 - BOLT
2 - RETAINER
3 - EXHAUST MANIFOLD
4 - NUT
5 - EXHAUST PIPE
Fig. 2 Exhaust Pipe(s) to Manifold Connection
1 - BOLT
2 - RETAINER
3 - EXHAUST MANIFOLD
4 - NUT
5 - EXHAUST PIPE
Fig. 3 Exhaust Pipe-to-Catalytic Converter Flange
Alignment Ð Typical
1 - 7.874±17.526 mm (0.31±0.69 in.)
2 - CATALYTIC CONVERTER FLANGE
3 - 20 mm (0.79 in.) MIN.
4 - CROSSMEMBER
5 - EXHAUST PIPE
6 - EXHAUST PIPE
11 - 6 EXHAUST SYSTEMDR
EXHAUST PIPE (Continued)

INSTALLATION
(1) Connect the exhaust pipe(s) to the exhaust
manifold. Tighten the nuts to 34 N´m (25 ft. lbs.)
torque.
(2) Align and connect the exhaust pipe to the cat-
alytic converter flange (Fig. 4). Install exhaust clamp
and tighten clamp nuts to 47 N´m (35 ft. lbs.) torque.
(3) Connect oxygen sensor connector(s).
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels.
Adjust the alignment, if needed.
EXHAUST PIPE
REMOVAL
(1) Disconnect the battery negative cables.
(2) Raise and support the vehicle on a hoist.
(3) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(4) Remove the exhaust pipe-to-extension pipe
clamp. Separate the exhaust pipe and extension pipe.
(5) Remove the exhaust pipe-to-turbocharger elbow
clamp (Fig. 5).
(6) Remove the exhaust pipe from the transmis-
sion support (Fig. 5).
INSPECTION
Discard rusted clamps, broken or worn supports
and attaching parts. Replace a component with orig-
inal equipment parts, or equivalent. This will assure
proper alignment with other parts in the system and
provide acceptable exhaust noise levels.
INSTALLATION
(1) Install the exhaust pipe into the transmission
support and onto the turbocharger flange.
(2) Install the exhaust pipe-to-turbocharger elbow
clamp and tighten to 31 N´m (23 ft. lbs.) torque.
(3) Install the extension pipe and clamp to the
exhaust pipe using a new clamp and tighten the
clamp nuts to 48 N´m (35 ft. lbs.) torque.
(4) Lower the vehicle.
(5) Connect the battery negative cables.
(6) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels. A
minimum of 25.4 mm (1.0 in.) is required. Adjust the
alignment, if needed.
HEAT SHIELDS
DESCRIPTION
There are two types of heat shields used. One is
stamped steel the other is molded foil sheets. The
shields attach to the vehicle around the exhaust sys-
tem to prevent heat from the exhaust system from
entering the passenger area and other areas where
the heat can cause damage to other components.
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the nuts or bolts holding the exhaust
heat shield to the floor pan (Fig. 6) (Fig. 7) (Fig. 8),
crossmember or bracket.
Fig. 4 Exhaust Pipe-to-Catalytic Converter Flange
AlignmentÐTypical
1 - 7.874±17.526 mm (0.31±0.69 in.)
2 - CATALYTIC CONVERTER FLANGE
3 - 20 mm (0.79 in.) MIN.
4 - CROSSMEMBER
5 - EXHAUST PIPE
6 - EXHAUST PIPE
Fig. 5 Exhaust Pipe
1 - Clamp
2 - Support
3 - EXHAUST PIPE
DREXHAUST SYSTEM 11 - 7
EXHAUST PIPE (Continued)