2003 DODGE RAM fuel cap

The relief valve spring has a free length of approx-
imately 49.5 mm (1.95 inches). The spring should
test between 19.5 and 20.5 pounds when compressed
to 34 mm (1-11/32 inches). Replace spring that fails
to meet these specifications (Fig. 66).
If oil pressure was low and pump is within specifi-
cations, inspect for worn engine bearings or other
reasons for oil pressure loss.
ASSEMBLY
(1) Install pump rotors and shaft, using new parts
as required.
(2) Position the oil pump cover onto the pump
body. Tighten cover bolts to 11 N´m (95 in. lbs.)
torque.
(3) Install the relief valve and spring. Insert the
cotter pin.
(4) Tap on a new retainer cap.
(5) Prime oil pump before installation by filling
rotor cavity with engine oil.
INSTALLATION
(1) Install oil pump. During installation slowly
rotate pump body to ensure driveshaft-to-pump rotor
shaft engagement.
(2) Hold the oil pump base flush against mating
surface on No.5 main bearing cap. Finger tighten
pump attaching bolts. Tighten attaching bolts to 41
N´m (30 ft. lbs.) torque.
(3) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
INTAKE MANIFOLD
DESCRIPTION
The aluminum intake manifold (Fig. 67) is a single
plane design with equal length runners and uses a
separate plenum, therefore the manifold does have a
plenum gasket. It also uses separate flange gaskets
and front and rear cross-over gaskets. Extreme care
must be used when sealing the gaskets to ensure
that excess sealant does not enter the intake runners
causing a restriction. Whenever the intake manifold
is removed inspect the plenum pan for evidence of
excess oil buildup, this condition indicates that the
plenum pan gasket is leaking.
OPERATION
The intake manifold, meters and delivers air to the
combustion chambers allowing the fuel delivered by
the fuel injectors to ignite, thus producing power.
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.
Fig. 66 Proper Installation of Retainer Cap
1 - RETAINER CAP
2 - CHAMFER
3 - COTTER KEY
Fig. 67 Intake Manifold and Throttle BodyÐV-8 Gas
Engines Typical
1 - FUEL RAIL ASSEMBLY
2 - FUEL RAIL MOUNTING BOLTS
3 - FUEL RAIL CONNECTING HOSES
9 - 274 ENGINE - 5.9LDR
OIL PUMP (Continued)

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 A/C compressor (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - REMOVAL).
(4) Remove the generator (Refer to 8 - ELECTRI-
CAL/CHARGING/GENERATOR - REMOVAL).
(5) Remove the accessory drive bracket.
(6) Remove the air cleaner.
(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 (Refer to 14
- FUEL SYSTEM/FUEL INJECTION/THROTTLE
CONTROL CABLE - REMOVAL) and if so equipped,
the speed control and transmission kickdown cables.
(9) Remove the return spring.
(10) Remove the distributor cap and wires.
(11) Disconnect the coil wires.
(12) Disconnect the heat indicator sending unit
wire.
(13) Disconnect the heater hoses and bypass hose.
(14) Remove the closed crankcase ventilation and
evaporation control systems.
(15) Remove intake manifold bolts.
(16) Lift the intake manifold and throttle body out
of the engine compartment as an assembly.
(17) Remove and discard the flange side gaskets
and the front and rear end seals.
(18) Remove the throttle body bolts and lift the
throttle body off the intake manifold (Fig. 68). Dis-
card the gasket.
(19) If required, remove the plenum pan and gas-
ket. Discard gasket.
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) If removed, position new plenum gasket and
install plenum pan (Fig. 69).
(2) Tighten plenum pan mounting bolts as follows:
²Step 1. Tighten bolts to 5.4 N´m (48 in. lbs.)
²Step 2. Tighten bolts to 9.5 N´m (84 in. lbs.)
²Step 3. Check all bolts are at 9.5 N´m (84 in.
lbs.)
(3) Install the flange gaskets. Ensure that the ver-
tical port alignment tab is resting on the deck face of
the block. Also the horizontal alignment tabs must be
in position with the mating cylinder head gasket tabs
(Fig. 71). The words MANIFOLD SIDE should be vis-
ible on the center of each flange gasket.
(4) Apply MopartGEN II Silicone Rubber Adhe-
sive Sealant, or equivalent, to 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 and 15 mm (0.6 in.)
long.
Fig. 68 Throttle Body Assembly
1 - FUEL RAIL ASSEMBLY
2 - FUEL RAIL MOUNTING BOLTS
3 - FUEL RAIL CONNECTING HOSES
DRENGINE - 5.9L 9 - 275
INTAKE MANIFOLD (Continued)

(5)Install the front and rear end seals (Fig. 70) Make
sure the molded dowel pins on the end seals fully enter the
corresponding holes in the cylinder block.
(6)Carefully lower intake manifold into position on
the cylinder block and cylinder heads. After intake man-
ifold is in place, inspect to make sure seals are in place.
(7) Using a new gasket, install the throttle body
onto the intake manifold. Tighten the bolts to 23 N´m
(200 in. lbs.) torque.(8) Install the intake manifold bolts and tighten as
follows (Fig. 72):
²Step 1. Tighten bolts 1 through 4 to 8 N´m (72
in. lbs.) Tighten in alternating steps 1.4 N´m (12 in.
lbs.) at a time
²Step 2. Tighten bolts 5 through 12 to 8 N´m (72
in. lbs.)
²Step 3. Check all bolts are torqued to 8 N´m (72
in. lbs.)
²Step 4. Tighten all bolts in sequence to 16 N´m
(12 ft. lbs.)
²Step 5. Check all bolts are torqued to 16 N´m
(12 ft. lbs.)
(9) Install closed crankcase ventilation and evapo-
ration control systems.
(10) Connect the coil wires.
(11) Connect the heat indicator sending unit wire.
(12) Connect the heater hoses and bypass hose.
(13) Install distributor cap and wires.
(14) Hook up the return spring.
(15) Connect the accelerator linkage (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION/THROTTLE
CONTROL CABLE - INSTALLATION) and if so
Fig. 69 Plenum Pan Bolt Tightening Sequence
Fig. 70 Front and Rear End Seals
1 - FRONT CROSS-OVER GASKET
2 - REAR CROSS-OVER GASKET
Fig. 71 Intake Manifold Flange Gasket Alignment
1 - FLANGE GASKET
2 - ALIGNMENT TABS
3 - CYLINDER HEAD GASKET
9 - 276 ENGINE - 5.9LDR
INTAKE MANIFOLD (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)

EXCESSIVE BLUE SMOKE
POSSIBLE CAUSE CORRECTION
Excessive piston ring end gap. Remove pistons and measure piston ring end gap
(Refer to 9 - ENGINE/ENGINE BLOCK/PISTON RINGS
- STANDARD PROCEDURE).
Excessive cylinder bore wear and taper. Remove pistons and measure cylinder bore wear and
taper (Refer to 9 - ENGINE/ENGINE BLOCK -
STANDARD PROCEDURE).
Cylinder damage. Remove pistons and inspect cylinder bore for cracks or
porosity. Repair with cylinder liner if necessary. (Refer
to 9 - ENGINE/ENGINE BLOCK - STANDARD
PROCEDURE).
Piston damage. Remove pistons and inspect for cracks, holes. Measure
piston for out-of-round and taper (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON & CONNECTING
ROD - INSPECTION).
Turbocharger failure. (Refer to 11 - EXHAUST SYSTEM/TURBOCHARGER
SYSTEM/TURBOCHARGER - INSPECTION).
DIAGNOSIS AND TESTINGÐCYLINDER
COMPRESSION/LEAKAGE TESTS
CYLINDER COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure batteries are completely charged and the
engine starter motor is in good operating condition.
Otherwise, the indicated compression pressures may
not be valid for diagnostic purposes.
(1) Disconnect the fuel inlet line to the fuel trans-
fer pump. Plug the fuel line from the fuel tank.
(2) Start the engine and idle until the engine stalls
(runs out of fuel).
(3) Disconnect all three injector wire harness con-
nectors at the rocker housing.
(4) Remove the breather cover and cylinder head
cover.
(5) Remove the high pressure fuel line between the
cylinder head and fuel rail for the cylinder to be
tested.
(6) Remove the exhaust rocker lever.
(7) Use Tool 9010 to remove the injector and cop-
per sealing washer.
(8) Install the exhaust rocker lever and torque to
43 N´m (32 ft. lbs.).
(9) Cover the remaining rocker levers with clean
shop towels to prevent any oil splatter under the
hood.
(10) Place a rag over the compression test tool fit-
ting. Crank the engine for 2±3 seconds to purge any
fuel that may have drained into the cylinder when
the injector was removed.(11) Connect the compression test gauge.
(12) Crank the engine for 5 seconds and record the
pressure reading. Repeat this step three times and
calculate the average of the three readings.
(13) Combustion pressure leakage can be checked
if cylinder pressure is below the specification. Per-
form the leakage test procedure on each cylinder
according to the tester manufacturer instructions.
(14) Upon completion of the test check an erase
any engine related fault codes.
CYLINDER COMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).
²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss
(1) Start and operate the engine until it attains
normal operating temperature.
(2) Remove the breather cover and cylinder head
cover.
(3) Disconnect all three injector wire harness con-
nectors at the rocker housing.
(4) Bring the cylinder to be tested to TDC.
(5) Remove the high pressure fuel line between the
cylinder head and the fuel rail for the cylinder to be
tested.
(6) Install capping Tool 9011 onto the rail.
(7) Remove the high pressure connector nut and
high pressure connector with Tool 9015.
(8) Remove the exhaust and intake rocker lever.
9 - 288 ENGINE 5.9L DIESELDR
ENGINE 5.9L DIESEL (Continued)

(35) Remove the passenger battery ground cable
from the engine block. Remove the driver side bat-
tery ground cable from the engine block.
(36) Remove power steering pump from engine by
removing 3 bolts.
(37) Remove accelerator linkage cover.
(38)
Disconnect cables from APPS if early model build
(39) If late model build,
(40) Disconnect the ECM power connector.
(41) Disconnect the ECM ground wire from the
hydroform screw.
(42) Disconnect the fuel supply and return hoses.
(43) Remove the cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(44) Disconnect the 3 injector harness connectors
at the rocker housing. Disconnect the wire harnesses
from the injectors.
(45) Remove the rear engine lift bracket.
(46) Remove cylinder #4, #5, and #6 intake and
exhaust rocker arms, pedestals, and push tubes. Note
the original location for re-assembly.
(47) Loosen #6 fuel line shield bolts and rotate
shield out of the way.
(48)
Remove cylinder #5 and #6 high pressure fuel
lines. Remove the fuel connector tube nut and fuel con-
nector tube. 46. Remove cylinder #5 and #6 fuel injector.
(49) Remove rocker housing.
(50) Remove two cylinder head bolts in location 4
and 12 according to the diagram below and install
Tool # 9009 (Fig. 3).(51) Loosen but do not remove engine mount
through bolts and nuts.
(52) Disconnect hood support struts and position
hood out of the way.
(53) Attach a chain with two hooks to the engine
lift brackets.
(54) While keeping engine level, lift straight up
out of the mounts.
(55) Rotate nose of engine upward and pull out of
chassis.
REMOVALÐCRANKCASE BREATHER
(1) Remove the oil fill cap.
(2) Remove the breather cover bolts (Fig. 4).
(3) Remove breather cover.
(4) Disconnect breather tube and lube oil drain
tube from breather.
(5) Remove breather mounting bolts.
(6) Remove breather from cylinder head cover.
INSTALLATION
INSTALLATIONÐENGINE
(1) Remove cylinder head bolts in locations 4 and
12 according to the diagram below. Install special
Tool 9009.Fig. 3 ENGINE LIFT BRACKET
1 - Head bolt
2 - Engine Lift Bracket
3 - Head Bolt
Fig. 4 Crankcase Breather Vapor Canister
1 - BREATHER COVER BOLT
2 - BREATHER COVER
3 - BREATHER TUBE
4 - ROCKER COVER
5 - BREATHER TUBE MOUNTING BRACKET
6 - LUBE OIL DRAIN TUBE
7 - O-RING
8 - BREATHER
9- BREATHER MOUNTING BOLT
DRENGINE 5.9L DIESEL 9 - 291
ENGINE 5.9L DIESEL (Continued)

(2) Lower engine into the engine compartment and
install the engine the engine mount through bolts
and nuts.
(3) Tighten the mount through bolts and nuts to
88 N-m (65 ft-lbs) torque.
(4) Remove the engine lifting device (Tool 9009).
(5) Check cylinder head capscrew length and
install into cylinder head.
(6) Torque alternately to 70 N-m (52 ft-lbs). Torque
alternately to 105 N-m (77 ft-lbs). Rotate 90 degrees.
(7) Install rocker housing. Torque to 24 N-m (18 ft-
lbs). Refer to Section 9 Rocker Housing Installation
(8) Replace injector o-ring and sealing washer on
injectors #5 and #6. Install injectors and alternately
tighten hold-down capscrews to 10 N-m (89 in-lbs).
(9) Install fuel connector tube and fuel connector
tube nut. Torque to 50 N-m (37 ft-lb). 10.
(10) Install #5 and #6 high pressure fuel lines. Fol-
low correct torque sequence per section 14. Torque
fuel line fittings to 30 N-m (22 ft-lb). Torque brace
capscrew to 24 N-m (18 ft-lb).
(11) Install rear engine lift bracket. Torque to 77
N-m (57 ft-lb).
(12) Install push tubes, rocker arms, and pedestals
for cylinders #4, #5, and #6. Torque the mounting
bolts to 36 N-m (27 ft-lbs).
(13) Reset valve lash on cylinders #4, #5, and #6.
Torque adjusting nuts to 24 N-m (18 ft-lbs).
(14) Install cylinder head cover. Torque to 24 N-m
(18 ft-lbs).(Refer to 9 - ENGINE/CYLINDER HEAD -
INSTALLATION).
(15) Connect breather tube and lube oil drain tube
to breather housing. Install breather housing. Torque
capscrews to 24 N-m (18 ft-lbs)
(16) Connect fuel supply and return hoses.
(17) Connect ECM ground to hydroform screw.
Connect ECM power connector.
(18) Install the APPS cable(s) to the APPS. Install
the throttle linkage cover.
(19) Install the power steering pump.
(20) Install the damper and speed indicator ring.
Torque to 40 N-m (30 ft-lb) plus 60 degrees.
(21) Connect the engine block heater connection.
(22) Connect the A/C compressor and pressure sen-
sor connectors
(23) Install the charge air cooler and a/c condenser
(if equipped). Install and tighten the charge air
cooler mounting bolts to 2 N-m (17 in-lbs).
(24) Connect the charge air cooler piping. Torque
all clamps to 8 N-m (72 in-lbs).
(25) Connect the a/c refrigerant lines to the a/c
condenser (if equipped).
(26) Install the radiator upper support panel.
(27) Install radiator.
(28) Connect the transmission quick-connect oil
cooler lines.(29) Raise vehicle.
(30) Connect a/c compressor suction/discharge hose
(if equipped).
(31) Install the radiator lower hose and clamps.
(32) Install the battery negative cables to the
engine block on the driver and passenger side.
(33) Install the transmission adapter with a new
camshaft rectangular ring seal. Torque to 77 N-m (57
ft-lb).
(34) Install the flywheel/flexplate. Torque to 137
N-m (101 ft-lb).
(35) Install the starter motor. Torque to 43 N-m
(32 ft-lb). (Refer to 8 - ELECTRICAL/STARTING/
STARTER MOTOR - INSTALLATION).
(36) Connect engine to vehicle harness connectors.
(37) Install transmission and transfer case (if
equipped).
(38) Connect the exhaust pipe to the turbocharger
elbow.
(39) Connect the transmission auxiliary oil cooler
lines (if equipped).
(40) Lower the vehicle.
(41)
Connect the heater core supply and return hoses.
(42) Install the cooling fan and upper fan shroud
at the same time. (Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - INSTALLATION).
(43) Install the coolant recovery bottle.
(44) Install the windshield washer bottle.
(45) Install the upper radiator hose and clamps.
(46) Raise vehicle.
(47) Connect electronically controlled fan drive
wire harness. Install lower radiator fan shroud.
(48) Change oil filter and install new engine oil.
(49) Fill the cooling system with coolant. (Refer to
7 - COOLING - STANDARD PROCEDURE).
(50) Connect grid heater harness at grid heater
relays.
(51) Connect electrical connections to rear of alter-
nator.
(52) Start the engine and inspect for engine oil,
coolant, and fuel leaks.
INSTALLATIONÐCRANKCASE BREATHER
(1) Install a new o-ring onto the breather element.
(2) Lubricate o-ring and install into cylinder head
cover. Torque capscrews to 10 N´m (89 in. lbs.).
(3) Connect breather tube and lube oil drain tube.
(4) Install breather cover (Fig. 4). Torque to 24
N´m (18 ft. lbs.)
(5) Install oil fill cap.
9 - 292 ENGINE 5.9L DIESELDR
ENGINE 5.9L DIESEL (Continued)

TORQUE
TORQUE CHART 5.9L DIESEL ENGINE
DESCRIPTION N´mIn.
Lbs.Ft.
Lbs.
Connecting RodÐBolts
Step 1 30 Ð 22
Step 2 60 Ð 44
Step 3 Rotate 60 degrees
Crankshaft Main CapÐBolts
Step 1 50 37
Step 2 80 59
Step 3 Rotate 90É
Cylinder HeadÐBolts
Step 1 70 Ð 52
Step 2 Back off 360 degrees
Step 3 105 Ð 77
Step 4 Verify 105 Ð 77
Step 5 Rotate All Bolts 1/4
Turn
Cylinder Head Cover Bolts 24 Ð 18
Breather Cover Bolts 24 Ð 18
HPC Nut 50 37
Fuel Delivery LinesÐBanjo 24 Ð 18
Fuel Drain LineÐBanjo 24 Ð 18
Fuel lineÐrail to cylinder
head30 Ð 22
Fuel lineÐpump to fuel rail 30 Ð 22
Injector fuel line brace 24 Ð 18
Fuel rail holddown bolt 24 18
Oil PanÐBolts 28 Ð 21
Oil PanÐDrain Plug 50 Ð 37
Oil Pressure RegulatorÐPlug 80 Ð 60
Oil Pressure Switch 18 Ð 13
Oil PumpÐBolts
Step1 8 Ð 6
Step2 24 Ð 18
Oil Suction Tube (Flange)Ð
Bolts24 Ð 18
Oil Suction Tube (Brace)Ð
Bolt43 Ð 32
Rocker Arm/PedestalÐBolts 36 Ð 27
SPECIAL TOOLS
5.9L DIESEL ENGINE
Universal Driver Handle - C4171
Crankshaft Barring Tool - 7471 - B
Crankshaft Front Oil Seal Installer - 8281
Valve Spring Compressor - 8319A
Test Plug - 8442
9 - 294 ENGINE 5.9L DIESELDR
ENGINE 5.9L DIESEL (Continued)