DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either per-
formance (e.g., engine idles rough and stalls) or
mechanical (e.g., a strange noise).
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING) - PERFORMANCE and (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)ÐMECHANICAL for
possible causes and corrections of malfunctions.
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
DIAGNOSIS AND TESTING) and (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION - DIAGNOSIS
AND TESTING) for the fuel system diagnosis.Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following diagnosis:
²Cylinder Compression Pressure Test (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING).
²Cylinder Combustion Pressure Leakage Test
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING).
²Engine Cylinder Head Gasket Failure Diagnosis
(Refer to 9 - ENGINE/CYLINDER HEAD - DIAGNO-
SIS AND TESTING).
²Intake Manifold Leakage Diagnosis (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
DIAGNOSIS AND TESTING).
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery 1. Charge or replace as necessary.
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to the terminals.
3. Faulty starter. 3. (Refer to 8 - ELECTRICAL/
STARTING - DIAGNOSIS AND
TESTING).
4. Faulty coil or control unit. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION COIL
- REMOVAL).
5. Incorrect spark plug gap. 5. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG -
CLEANING).
6. Dirt or water in fuel system. 6. Clean system and replace fuel
filter.
7. Faulty fuel pump, relay or wiring. 7. Repair or replace as necessary.
DRENGINE - 5.7L 9 - 183
ENGINE - 5.7L (Continued)
(6) Remove the viscous fan/drive (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - REMOVAL).
(7) Remove radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - REMOVAL).
(8) Remove the upper crossmember and top core
support.
NOTE: It is not necessary to drain A/C system for
engine removal.
(9) Remove the A/C compressor with the lines
attached. Secure compressor out of the way.
(10) Remove generator assembly (Refer to 8 -
ELECTRICAL/CHARGING/GENERATOR -
REMOVAL).
(11) Remove the intake manifold and IAFM as an
assembly(Refer to 9 - ENGINE/MANIFOLDS/IN-
TAKE MANIFOLD - REMOVAL).
(12) Disconnect the heater hoses.
NOTE: It is not necessary to disconnect P/S hoses
from pump, for P/S pump removal.
(13) Remove the power steering pump and set
aside.
(14) Disconnect the fuel supply line (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/QUICK CON-
NECT FITTING - STANDARD PROCEDURE).
(15) Raise and support the vehicle on a hoist and
drain the engine oil.
(16) Remove engine front mount thru-bolt nuts.
(17) Remove right side axle retaining bolts.
(18) Disconnect the transmission oil cooler lines
from their retainers at the oil pan bolts.
(19) Disconnect exhaust pipe at manifolds.
(20) Disconnect the starter wires. Remove starter
motor (Refer to 8 - ELECTRICAL/STARTING/
STARTER MOTOR - REMOVAL).
(21) Remove the structural dust cover and trans-
mission inspection cover,(Refer to 9 - ENGINE/EN-
GINE BLOCK/STRUCTURAL COVER - REMOVAL).
(22) Remove drive plate to converter bolts (Auto-
matic transmission equipped vehicles).
(23) Remove transmission bell housing to engine
block bolts.
(24) Lower the vehicle.
(25) Install engine lift fixture, special tool # 8984.
(26) Separate engine from transmission, remove
engine from vehicle, and install engine assembly on a
repair stand.
INSTALLATION
(1) Install engine lift fixture Special tool # 8984.
(2) Position the engine in the engine compartment.
(3) Lower engine into compartment and align
engine with transmission:²Manual Transmission: Align clutch disc assem-
bly (if disturbed). Install transmission input shaft
into clutch disc while mating engine and transmis-
sion surfaces. Install two transmission to engine
block mounting bolts finger tight.
²Automatic Transmission: Mate engine and trans-
mission and install two transmission to engine block
mounting bolts finger tight.
(4) Position the thru-bolt into the support cushion
brackets.
(5) Lower engine assembly until engine mount
through bolts rest in mount perches.
(6) Install remaining transmission to engine block
mounting bolts and tighten.
(7) Tighten engine mount through bolts.
(8) Install drive plate to torque converter bolts.
(Automatic transmission models)
(9) Install the structural dust cover and transmis-
sion dust cover,(Refer to 9 - ENGINE/ENGINE
BLOCK/STRUCTURAL COVER - INSTALLATION).
(10) Install the starter and connect the starter
wires (Refer to 8 - ELECTRICAL/STARTING/
STARTER MOTOR - INSTALLATION).
(11) Install exhaust pipe to manifold.
(12) Lower the vehicle.
(13) Remove engine lift fixture, special tool # 8984.
(14) Connect the fuel supply line (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/QUICK CON-
NECT FITTING - STANDARD PROCEDURE).
(15) Reinstall the power steering pump.
(16) Connect the heater hoses.
(17) Install the intake manifold.
(18) Using a new gasket, install throttle body
(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/
THROTTLE BODY - INSTALLATION).
(19) Install the generator and wire connections
(Refer to 8 - ELECTRICAL/CHARGING/GENERA-
TOR - INSTALLATION).
(20) Install a/c compressor and lines (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - INSTALLATION).
(21) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(22) Install upper radiator support crossmember.
(23) Install radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - INSTALLATION).
(24) Connect the radiator lower hose.
(25) Connect the transmission oil cooler lines to
the radiator.
(26) Install the fan shroud.
(27) Install the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - INSTALLATION).
(28) Connect the radiator upper hose.
(29) Install the washer bottle.
(30) Connect the transmission cooler lines.
DRENGINE - 5.7L 9 - 191
ENGINE - 5.7L (Continued)
(10) Drain engine oil. Remove and discard the oil
filter (Refer to 9 - ENGINE/LUBRICATION/OIL FIL-
TER - REMOVAL).
(11) Install the drain plug. Tighten the plug to 50
N´m (37 ft. lbs.) torque.
(12) Install a new oil filter (Refer to 9 - ENGINE/
LUBRICATION/OIL FILTER - INSTALLATION).
(13) Fill engine crankcase with the specified
amount and grade of oil (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES - SPECIFICA-
TIONS).
(14) Connect the negative cable(s) to the battery.
(15) Start the engine and check for any leaks.
REMOVAL
REMOVAL - ENGINE
(1) Disconnect both battery negative cables.
(2) Disconnect engine grid heater harness at grid
heater relays.
(3) Disconnect electrical connections from rear of
alternator.
(4) Recover A/C refrigerant. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE).
(5) Raise vehicle on a hoist.
(6) Drain engine coolant (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(7) Remove engine oil drain plug and drain engine
oil.
(8) Reinstall drain plug. Tighten to 50N´m (37 ft.
lbs.) torque.
(9) Lower the vehicle.
(10) Remove fan/drive assembly. Refer to Section 7
± Fan/Drive Removal
(11) Remove radiator upper hose.
(12) Remove upper fan shroud mounting bolts.
(13) Disconnect the coolant recovery bottle hose
from the radiator fill neck and remove bottle.
(14) Using a 36mm wrench, remove viscous fan/
drive assembly. (Refer to 7 - COOLING/ENGINE/RA-
DIATOR FAN - REMOVAL).
(15) Remove cooling fan and shroud together.
(16) Disconnect heater core supply and return
hoses from the cylinder head fitting and coolant pipe.
(17) Raise vehicle on a hoist.
(18) Remove transmission and transfer case (if
equipped).
(19) Disconnect exhaust pipe from turbocharger
extension pipe.
(20) Disconnect engine harness to vehicle harness
connectors.
(21) Remove starter motor (Refer to 8 - ELECTRI-
CAL/STARTING/STARTER MOTOR - REMOVAL).(22) Remove flywheel/flexplate.
(23) Remove transmission adapter
(24) Disconnect A/C suction/discharge hose from
the rear of the A/C compressor.
(25) Lower vehicle.
(26) Disconnect lower radiator hose from radiator
outlet.
(27) Automatic transmission models:
(28) Disconnect transmission oil cooler lines from
in front of radiator using special tool #6931
(29) Remove radiator. (Refer to 7 - COOLING/EN-
GINE/RADIATOR - REMOVAL).
(30) If A/C equipped, disconnect A/C condenser
refrigerant lines.
(31) Disconnect charge air cooler piping.
(32) Remove charge air cooler mounting bolts.
(33) Remove charge air cooler (and A/C condenser
if equipped) from vehicle.
(34) Remove damper and speed indicator ring from
front of engine.
(35) Disconnect engine block heater connector.
(36) Disconnect A/C compressor and pressure sen-
sor electrical connectors.
(37) Remove the passenger battery ground cable
from the engine block. Remove the driver side bat-
tery ground cable from the engine block.
(38) Remove power steering pump from engine by
removing 3 bolts.
(39) Remove accelerator linkage cover.
(40) Disconnect cables from on-engine APPS.
(41) Disconnect the ECM power connector.
(42) Disconnect the ECM ground wire from the
hydroform screw.
(43) Disconnect the fuel supply and return hoses.
(44) Remove the cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(45) Disconnect the 3 injector harness connectors
at the rocker housing. Disconnect the wire harnesses
from the injectors.
(46) Remove the rear engine lift bracket.
(47) Remove cylinder #4, #5, and #6 intake and
exhaust rocker arms, pedestals, and push tubes. Note
the original location for re-assembly.
(48) Loosen #6 fuel line shield bolts and rotate
shield out of the way.
(49) Remove cylinder #5 and #6 high pressure fuel
lines. Remove the fuel connector tube nut and fuel
connector tube. Remove cylinder #5 and #6 fuel injec-
tor.
(50) Remove rocker housing.
DRENGINE 5.9L DIESEL 9 - 241
ENGINE 5.9L DIESEL (Continued)
(8) Replace injector o-ring and sealing washer on
injectors #5 and #6. Install injectors and torque using
the following steps:
²Step 1ÐInstall injector hold-down capscrews
and torque to 5 N´m (44 in. lbs.) torque.
²Step 2ÐLoosen injector hold-down capscrews.
²Step 3ÐInstall HPC connector tube and nut.
Torque nut to 15 N´m (11 ft. lbs.) torque.
²Step 4ÐTorque injector hold-down capscrews to
10 N´m (89 in. lbs.) torque.
²Step 5ÐTorque HPC connector tube nut to 50
N´m (37 ft. lbs.) torque.
(9) 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).
(10) Install rear engine lift bracket. Torque to 77
N-m (57 ft-lb).
(11) Install push tubes, rocker arms, and pedestals
for cylinders #4, #5, and #6. Torque the mounting
bolts to 36 N-m (27 ft-lbs).
(12) Reset valve lash on cylinders #4, #5, and #6.
Torque adjusting nuts to 24 N-m (18 ft-lbs).
(13) Install cylinder head cover. Torque to 24 N-m
(18 ft-lbs).(Refer to 9 - ENGINE/CYLINDER HEAD -
INSTALLATION).
(14) Connect breather tube and lube oil drain tube
to breather housing cover. Install breather housing.
Torque capscrews to 24 N-m (18 ft-lbs)
(15) Connect fuel supply and return hoses.
(16) Connect ECM ground to hydroform screw.
Connect ECM power connector.
(17) Install the APPS cable(s) to the APPS. Install
the throttle linkage cover.
(18) Install the power steering pump.
(19) Install the damper and speed indicator ring.
Torque to 40 N-m (30 ft-lb) plus 60 degrees.
(20) Connect the engine block heater connection.
(21) Connect the A/C compressor and pressure sen-
sor connectors
(22) 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).
(23) Connect the charge air cooler piping. Torque
all clamps to 8 N-m (72 in-lbs).
(24) Connect the a/c refrigerant lines to the a/c
condenser (if equipped).
(25) Install the radiator upper support panel.
(26) Install radiator.
(27) Connect the transmission quick-connect oil
cooler lines.(28) Raise vehicle.
(29) Connect a/c compressor suction/discharge hose
(if equipped).
(30) Install the radiator lower hose and clamps.
(31) Install the battery negative cables to the
engine block on the driver and passenger side.
(32) Install the transmission adapter with a new
camshaft rectangular ring seal. Torque to 77 N-m (57
ft-lb).
(33) Install the flywheel/flexplate. Torque to 137
N-m (101 ft-lb).
(34) Install the starter motor. Torque to 43 N-m
(32 ft-lb). (Refer to 8 - ELECTRICAL/STARTING/
STARTER MOTOR - INSTALLATION).
(35) Connect engine to vehicle harness connectors.
(36) Install transmission and transfer case (if
equipped).
(37) Connect the exhaust pipe to the turbocharger
elbow.
(38) Connect the transmission auxiliary oil cooler
lines (if equipped).
(39) Lower the vehicle.
(40) Connect the heater core supply and return
hoses.
(41) Install the cooling fan and upper fan shroud
at the same time. (Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - INSTALLATION).
(42) Install the coolant recovery bottle.
(43) Install the windshield washer bottle.
(44) Install the upper radiator hose and clamps.
(45) Raise vehicle.
(46) Connect electronically controlled fan drive
wire harness. Install lower radiator fan shroud.
(47) Change oil filter and install new engine oil.
(48) Fill the cooling system with coolant. (Refer to
7 - COOLING - STANDARD PROCEDURE).
(49) Connect grid heater harness at grid heater
relays.
(50) Connect electrical connections to rear of alter-
nator.
(51) 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.
DRENGINE 5.9L DIESEL 9 - 243
ENGINE 5.9L DIESEL (Continued)
(9) Install rocker housing and bolts. Tighten to 24
Nm (18 lb. ft.).
(10) Install fuel injector(Refer to 14 - FUEL SYS-
TEM/FUEL INJECTION/FUEL INJECTOR -
INSTALLATION).
(11) Install injector harness nuts. Tighten to 1.25
Nm (11 lb. in.).
(12) Install cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(13) Install wire harness P-clip to cylinder head
behind filter housing 24 N´m (18 ft. lbs.).
(14) Connect the IAT/MAP sensor connector.
(15) Install the fuel filter canister assembly and
torque mounting bolts to 24 N´m (18 ft. lbs.).
(16) Connect fuel lift pump, WIF sensor, and fuel
heater.
(17) Remove the engine lift bracket at rear of cyl-
inder head.
CAUTION: Failure to follow procedure will result in
fuel leaks and/or fuel system failure.
(18)Install the fuel rail and high pressure
fuel lines as follows:
(a) Hand tighten fuel rail bolts.
(b) Hand tighten fuel drain line to pressure lim-
iting valve. Hand tighten banjo bolt at fuel filter
housing.
(c) Hand tighten fuel rail-to-cylinder head high
pressure fuel lines.(d) Install fuel line brace bolts-to-intake mani-
fold finger tight.
(e) Hand tighten fuel pump to fuel rail line.
(f) Torque fuel line nuts at cylinder head to 30
Nm ( 22 ft. lbs.).
(g) Torque fuel line nuts at fuel rail to 30 Nm
(22 ft. lbs.)
(h) Using a back up wrench, torque fuel pump to
fuel rail line to 37 Nm (27 ft. lbs.). At injection
pump.
(i) Torque fuel pump to fuel rail line to 37 Nm
(27 ft. lbs.) at fuel rail.
(j) Torque fuel drain banjo bolt at pressure lim-
iting valve and front of fuel filter housing to 24 Nm
(18 ft. lbs.).
(k) Torque fuel line brace bolts to 24 N´m (18 ft.
lbs.).
(l) Torque rail bolts to 24 Nm (18 ft. lbs.).
(m) Connect fuel pressure sensor.
(19) Install the engine lift bracket at the rear of
cylinder head. Torque to 77 N´m (57 ft. lbs.).
(20) Reposition number 6 fuel line shield and
torque to 43 N´m (32 ft. lbs.).
(21) Install the fuel filter to injection pump low
pressure line. Inspect and replace sealing washers if
necessary. Torque banjo bolts to 24 N´m (18 ft. lbs.).
(22) Connect fuel return line at back of cylinder
head hand tight.
(23) Connect fuel return line at filter housing hand
tight.
(24) Torque banjo connections at cylinder head and
fuel filter housing to 24 Nm (18 ft. lbs.)
(25) Install bracket to rear of filter housing.
Torque to 24 Nm (18 ft. lbs.).
(26) Using new gaskets, install the intake grid
heater and air inlet housing. Torque bolts to 24 N´m
(18 ft. lbs.).
(27) Install wire harness P-clip and push on clip to
air inlet housing.
(28) Connect engine oil level indicator tube at fuel
filter housing and at air inlet housing.
(29) Connect the APPS connector.
(30) Install the APPS assembly to the cylinder
head bracket and torque bolts to 24 N´m (18 ft. lbs.).
(31) Install the throttle linkage cover.
(32) Install the charge air cooler-to-air inlet hous-
ing duct assembly. Torque all clamps to 11 N´m (100
in. lbs.).
(33) Connect intake grid heater wires.
(34) Secure engine harness to front of cylinder
head with bolt at four locations.
(35) Connect engine coolant temperature sensor
connector.
(36) Connect radiator upper hose to thermostat
housing.
Fig. 20 Rocker Arm and Pedestal Removal
1 - ROCKER ARM
2 - PEDESTAL
9 - 254 ENGINE 5.9L DIESELDR
CYLINDER HEAD (Continued)
(13) Install the cooling fan (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - INSTALLATION).
(14) Connect battery negative cables.
(15) Start engine and check for oil leaks.
INTAKE MANIFOLD
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove the charge air cooler outlet tube from
the air inlet housing (Fig. 118).
(3) Remove the engine oil dipstick tube mounting
bolt (Fig. 118).
(4) Remove dipstick support at fuel filter housing.
Position dipstick tube to the side.
(5) Disconnect the air grid heater power cables at
the cable mounting studs.
(6) Disconnect the ground strap at the intake
cover.
(7) Remove the engine wiring harness connections
at the air inlet housing elbow.
(8) Remove the four (4) air inlet housing mounting
bolts and remove the housing from top of the heater
elements.
(9) Remove the intake air grid heater from the
manifold (Fig. 119).
(10) Remove the high pressure fuel lines and fuel
rail (Refer to 14 - FUEL SYSTEM/FUEL DELIVERY/
FUEL LINES - REMOVAL).
(11) Remove APPS bracket from cylinder head to
gain access to front intake manifold cover bolts.
(12) Disconnect manifold air temperature/pressure
sensor connector.
(13) Remove the remaining intake manifold cover-
to-cylinder head bolts.
(14) Remove the intake manifold cover and gasket.
Keep the gasket material and any other material out
of the air intake.
(15) Clean the intake manifold cover and cylinder
head sealing surface.
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.
Fig. 118 Charge Air Cooler Air Tube
1 - FRONT WIRING CLIP
2 - GROUND CABLE
3 - TUBE BOLT
4 - ENGINE OIL DIPSTICK TUBE
5 - CLAMPS
6 - AIR TUBE (INT. MAN.-TO-INTERCOOLER)
7 - RUBBER HOSE
8 - AIR INTAKE HOUSING
9 - CABLE BRACKET HOUSING
Fig. 119 Intake Air Grid Heater
1 - INTAKE AIR GRID HEATER
2 - GASKET
DRENGINE 5.9L DIESEL 9 - 297
OIL PUMP (Continued)
(3) Install heat shield and torque nuts to 15 Nm
(11 ft. lbs.).
(4) Install cab heater tube.
(5) Install exhaust manifold bolt retention straps.
(6) Install the cab heater return hose to the man-
ifold bolt stud. Tighten the nut to 24 N´m (18 ft. lbs.)
torque.
(7) Install the turbocharger and a new gasket.
Apply anti-seize to the studs and then tighten the
turbocharger mounting nuts to 43 N´m (32 ft. lbs.)
torque.
(8)Pre-lube the turbocharger.Pour 50 to 60 cc
(2 to 3 oz.) clean engine oil in the oil supply line fit-
ting on the turbo. Rotate the turbocharger impeller
by hand to distrubute the oil thoroughly.
(9) Install and tighten the oil supply line fitting
nut to 24 N´m (18 ft. lbs.) torque.
(10) Position the charge air cooler inlet pipe to the
turbocharger. With the clamp in position, tighten the
clamp nut to 11 N´m (100 in. lbs.) torque.
(11) Position the air inlet hose to the turbocharger.
Tighten the clamp to 11 N´m (100 in. lbs.) torque.
(12) Raise vehicle on hoist.
(13) Install the oil drain tube and a new gasket to
the turbocharger. Tighten the drain tube bolts to 24
N´m (18 ft. lbs.) torque.
(14) Connect the exhaust pipe to the turbocharger
and tighten the bolts to 11 N´m (100 ft. lbs.) torque.
(15) Lower the vehicle.
(16) Connect the battery negative cables.
(17) Start the engine to check for leaks.
VALVE TIMING
STANDARD PROCEDURE - TIMING
VERIFICATION
(1) Remove the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) Remove fuel injector from cylinder number
1(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/
FUEL INJECTOR - REMOVAL).
(3) Using Special Tool 7471B rotate the engine
until the TDC mark on the damper is at 12 o'clock.
(4) Using a 8 in.x 1/4 in. dowel rod inserted into
cylinder number 1, rock the crankshaft back and
forth to verify piston number 1 is at TDC.
(5) With cylinder number still at TDC, inspect the
keyway on the crankshaft gear for proper alignment
(12 o'clock position).
(6) If the keyway is not at 12 o'clock position
replace the crankshaft gear assembly.
(7) If the keyway is at 12 o'clock position, remove
front gear cover and verify timing mark alignmentbetween the camshaft gear and crankshaft gear, if
not aligned inspect keyway on camshaft gear.
(8) Inspect keyway on camshaft gear for proper
alignment with the key in the camshaft, if alignment
is off replace the camshaft/gear assembly.
(9) If timing marks alignment is off and no dam-
age is found at either the crankshaft or camshaft
gear keyways, realign timing marks as necessary.
GEAR HOUSING
REMOVAL
(1) Disconnect the battery negative cables.
(2) Raise vehicle on hoist.
(3) Partially drain engine coolant into container
suitable for re-use (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(4) Lower vehicle.
(5) Remove radiator upper hose.
(6) Disconnect coolant recovery bottle hose from
radiator filler neck and lift bottle off of fan shroud.
(7) Disconnect windshield washer pump supply
hose and electrical connections and lift washer bottle
off of fan shroud.
(8) Remove lower fan shroud fasteners. Disconnect
fan drive wire harness.
(9) Remove the upper fan shroud-to-radiator
mounting bolts.
(10) Remove viscous fan/drive assembly (Refer to 7
- COOLING/ENGINE/RADIATOR FAN - REMOVAL).
(11) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(12) Remove the cooling fan support/hub from the
front of the engine.
(13) Raise the vehicle on hoist.
(14) Remove the crankshaft damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL) and speed indicator ring.
(15) Lower the vehicle.
(16) Remove the power steering pump.
(17) Remove the accessory drive belt tensioner.
(18) Remove the gear cover-to-housing bolts and
gently pry the cover away from the housing, taking
care not to mar the gasket surfaces.
(19) Remove the fuel injection pump (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/FUEL INJEC-
TION PUMP - REMOVAL).
(20) Disconnect the camshaft position sensor con-
nector.
(21) Disconnect and remove engine speed sensor.
(22) Remove the camshaft (Refer to 9 - ENGINE/
ENGINE BLOCK/CAMSHAFT & BEARINGS (IN
BLOCK) - REMOVAL).
(23) Remove the six front oil pan fasteners.
DRENGINE 5.9L DIESEL 9 - 299
EXHAUST MANIFOLD (Continued)
OPERATION
Fuel is returned through the fuel pump module
and back into the fuel tank through the fuel filter/
fuel pressure regulator. A separate fuel return line
from the engine to the tank is not used.
The fuel tank assembly consists of: the fuel tank,
fuel pump module assembly, fuel pump module lock-
nut/gasket, and fuel tank check valve (refer to Fuel
Tank Check Valve for information).
A fuel filler/vent tube assembly using a pressure/
vacuum, 1/4 turn fuel filler cap is used. The fuel
filler tube contains a flap door located below the fuel
fill cap.
Also to be considered part of the fuel system is the
evaporation control system. This is designed to
reduce the emission of fuel vapors into the atmo-sphere. The description and function of the Evapora-
tive Control System is found in Emission Control
Systems.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.
STANDARD PROCEDURE - FUEL SYSTEM
PRESSURE RELEASE
Use following procedure if the fuel injector
rail is, or is not equipped with a fuel pressure
test port.
(1) Remove fuel fill cap.
Fig. 1 FUEL DELIVERY COMPONENTS
1 - FUEL TANK 8 - LDP FRESH AIR FILTER
2 - CHECK VALVE 9 - LEAK DETECTION PUMP
3 - LIQUID EXPANSION CHAMBER 10 - EVAP CANISTERS (2)
4 - FUEL FILTER / FUEL PRESSURE REGULATOR 11 - FUEL TANK STRAPS (2)
5 - QUICK-CONNECT FITTING AND FUEL LINE (TO ENGINE) 12 - CHECK VALVE
6 - EVAP LINE CONNECTION 13 - FUEL PUMP MODULE LOCK RING
7 - LEAK DETECTION PUMP FRESH AIR LINE 14 - FUEL PUMP MODULE
14 - 2 FUEL DELIVERY - GASDR
FUEL DELIVERY - GAS (Continued)