2003 JEEP GRAND CHEROKEE head gasket

relief holes in the rear cam journal. The oil pressure
relief holes must be free of debris.
INSTALLATION
INSTALLATION - CAMSHAFT BEARINGS
CAUTION: Make sure outside diameter of number 1
bearing is clean. Make sure that the bearing is
properly installed in the engine block, align the oil
hole in the bearing with the oil gallery in the bear-
ing bore. Failure to do so will cause inadequate oil
supply for the sprockets and timing chain.
(1) Using recommended special tool 8544 Cam-
shaft Bearing Remover/Installer, install new cam-
shaft bearings.
INSTALLATION - CAMSHAFT
(1) Lubricate the camshaft with MopartEngine
Oil Supplement, or equivalent.
(2) Carefully install the camshaft to prevent dam-
age to the camshaft bearings.
(3) Position thrust plate and install retaining
screws. Tighten screws to 24 N´m (18 ft. lbs.).
(4) Lubricate the camshaft with Mopartengine oil
supplement, or equivalent.
(5) Install the camshaft sprocket, crankshaft
sprocket and timing chain (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - INSTALLATION).
(6) Tighten the camshaft sprocket bolt and washer
to 68 N´m (50 ft. lbs.).
(7) To verify correct installation of the timing
chain, turn the crankshaft two full revolutions then
position the camshaft sprocket timing mark as shown
in (Fig. 33).
(8) Install the timing case cover with a replace-
ment oil seal (Fig. 34). (Refer to 9 - ENGINE/VALVE
TIMING/TIMING BELT / CHAIN COVER(S) -
INSTALLATION).
(9) Install the vibration damper (Fig. 34) (Refer to
9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - INSTALLATION).
(10) Install the hydraulic valve tappets (Refer to 9
- ENGINE/ENGINE BLOCK/HYDRAULIC LIFTERS
(CAM IN BLOCK) - INSTALLATION).
(11) Install the cylinder head gasket with the
numbers facing up.
(12) Install the cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - INSTALLATION).
(13) Install the push rods.
(14) Install the rocker arms and pivot and bridge
assemblies (Refer to 9 - ENGINE/CYLINDER HEAD/
ROCKER ARM / ADJUSTER ASSY - INSTALLA-
TION).
(15) Install the engine cylinder head cover (Refer
to 9 - ENGINE/CYLINDER HEAD/CYLINDER
HEAD COVER(S) - INSTALLATION).
Fig. 31 Camshaft Removal
1 - CAMSHAFT
2 - CRANKSHAFT
Fig. 32 Crankshaft / Camshaft Sprocket Timing Mark
Alignment
1 - CAMSHAFT SPROCKET
2 - TIMING MARKS
3 - CRANKSHAFT SPROCKET
9 - 32 ENGINE - 4.0LWJ
CAMSHAFT & BEARINGS (Continued)

PISTON SIZE CHART
CYLINDER BORE SIZE PISTON LETTER SIZE
98.438 - 98.448 mm
(3.8755 - 3.8759 in.)A
98.448 - 98.458 mm
(3.8759 - 3.8763 in.)B
98.458 - 98.468 mm
(3.8763 - 3.8767 in.)C
98.468 - 98.478 mm
(3.8767 - 3.8771 in.)D
98.478 - 98.488 mm
(3.8771 - 3.8775 in.)E
98.488 - 98.498 mm
(3.8775 - 3.8779 in.)F
REMOVAL
(1) Remove the engine cylinder head cover. (Refer
to 9 - ENGINE/CYLINDER HEAD/CYLINDER
HEAD COVER(S) - REMOVAL).
(2) Remove the rocker arms, bridges and pivots.
(3) Remove the push rods.
(4) Remove the engine cylinder head. (Refer to 9 -
ENGINE/CYLINDER HEAD - REMOVAL).
(5) Position the pistons one at a time near the bot-
tom of the stroke. Use a ridge reamer to remove theridge from the top end of the cylinder walls. Use a
protective cloth to collect the cuttings.
(6) Raise the vehicle.
(7) Drain the engine oil.
(8) Remove the oil pan and gasket. (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - REMOVAL).
(9) Remove main bearing cap brace (Fig. 58).
(10) Remove the connecting rod bearing caps and
inserts. Mark the caps and rods with the cylinder
bore location. The connecting rods and caps are
stamped with a two letter combination (Fig. 59).
Fig. 57 Bore Gauge
1 - FRONT
2 - BORE GAUGE
3 - CYLINDER BORE
4 - 49.5 MM (1-15/16 in.)
Fig. 58 Main Bearings Caps and Brace
1 - BLOCK
2 - MAIN BEARING CAP BRACE
Fig. 59 Stamped Connecting Rods and Caps
1 - CONNECTING ROD CAP
2 - CONNECTING ROD
WJENGINE - 4.0L 9 - 45
PISTON & CONNECTING ROD (Continued)

(12) Install the oil pan and gasket (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
(13) Lower the vehicle.
(14) Install the engine cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - INSTALLATION),
push rods, rocker arms, bridges, pivots and engine
cylinder head cover(Refer to 9 - ENGINE/CYLINDER
HEAD/CYLINDER HEAD COVER(S) - INSTALLA-
TION).
(15) Fill the crankcase with engine oil.
PISTON RINGS
STANDARD PROCEDURE - PISTON RING
FITTING
(1) Carefully clean the carbon from all ring
grooves. Oil drain openings in the oil ring groove and
pin boss must be clear. DO NOT remove metal from
the grooves or lands. This will change ring-to-groove
clearances and will damage the ring-to-land seating.
(2) Be sure the piston ring grooves are free of
nicks and burrs.
(3) Measure the ring side clearance with a feeler
gauge fitted snugly between the ring land and ring
(Fig. 62) (Fig. 63). Rotate the ring in the groove. It
must move freely around circumference of the groove.
RING SIDE CLEARANCE CHART
ITEM SPECIFICATION
Top Compression Ring 0.042 - 0.084 mm
(0.0017 - 0.0033 in.)
Second Compression
Ring0.042 - 0.084 mm
(0.0017 - 0.0033 in.)
Oil Control Ring 0.06 - 0.21 mm
(0.0024 - 0.0083 in.)
(4) Place ring in the cylinder bore and push down
with inverted piston to position near lower end of the
ring travel. Measure ring gap with a feeler gauge fit-
ting snugly between ring ends (Fig. 64).
RING GAP MEASUREMENT CHART
ITEM SPECIFICATION
Top Compression Ring 0.229 - 0.610 mm
(0.0090 - 0.0240 in.)
Second Compression
Ring0.483 - 0.965 mm
(0.0190 - 0.080 in.)
Oil Control Ring 0.254 - 1.500 mm
(0.010 - 0.060 in.)
Fig. 62 Piston Dimensions
Fig. 63 Ring Side Clearance Measurement
1 - FEELER GAUGE
WJENGINE - 4.0L 9 - 47
PISTON & CONNECTING ROD (Continued)

(10) Place a piece of wood (2 x 2) between the jack
stand and the engine vibration damper.
(11) Remove the engine mount through bolts.
(12) Using the jack stand, raise the engine until
adequate clearance is obtained to remove the oil pan.
(13) Remove transmission oil cooling lines (if
equipped) and oxygen sensor wiring supports that
are attached to the oil pan studs.
(14) Remove the oil pan bolts and studs. Carefully
slide the oil pan and gasket to the rear. If equipped
with an oil level sensor, take care not to damage the
sensor.
INSTALLATION
(1) Clean the block and pan gasket surfaces.
(2) Fabricate 4 alignment dowels from 1 1/2 x 1/4
inch bolts. Cut the head off the bolts and cut a slot
into the top of the dowel. This will allow easier
installation and removal with a screwdriver (Fig. 78).
(3) Install two dowels in the timing case cover.
Install the other two dowels in the cylinder block
(Fig. 79).
(4) Apply MopartSilicone Rubber Adhesive Seal-
ant on cylinder block to rear main bearing cap cor-
ners and cylinder block to front cover joints (four
places) (Fig. 80).
(5) Slide the one-piece gasket over the dowels and
onto the block and timing case cover.
(6) Position the oil pan over the dowels and onto
the gasket. If equipped with an oil level sensor, take
care not to damage the sensor.
(7) Install the 1/4 inch oil pan bolts. Tighten these
bolts to 9.5 N´m (84 in. lbs.) torque. Install the 5/16
inch oil pan bolts (Fig. 81). Tighten these bolts to 15
N´m (132 in. lbs.) torque.
(8) Remove the dowels. Install the remaining 1/4
inch oil pan bolts. Tighten these bolts to 9.5 N´m (84
in. lbs.) torque.
Fig. 78 Fabrication of Alignment Dowels
1 - 1/488ý 1 1/288BOLT
2 - DOWEL
3 - SLOT
Fig. 79 Position of Dowels in Cylinder Block
1 - DOWEL HOLES
2 - CYLINDER BLOCK
3 - 5/1688HOLES
4 - 5/1688HOLES
Fig. 80 Oil Pan Sealer Location
1 - SEALER LOCATIONS
Fig. 81 Position of 5/16 inch Oil Pan Bolts
1 - OIL PAN
2 - OIL PAN DRAIN PLUG
WJENGINE - 4.0L 9 - 55
OIL PAN (Continued)

INSTALLATION
A gear-type oil pump is mounted at the underside
of the cylinder block opposite the No.4 main bearing.
(1) Install the oil pump on the cylinder block using
a replacement gasket. Tighten the bolts to 23 N´m
(17 ft. lbs.) torque.
(2) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
(3) Fill the oil pan with oil to the specified level.
INTAKE MANIFOLD
DESCRIPTION
The intake manifold (Fig. 83) is made of cast alu-
minum and uses eleven bolts to mount to the cylin-
der head. This mounting style improves sealing and
reduces the chance of leaks.
DIAGNOSIS AND TESTING - INTAKE
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 RPM is observed the area of the
suspected leak has been found.
(4) Repair as required.
REMOVAL
NOTE: THE ENGINE INTAKE AND EXHAUST MANI-
FOLD MUST BE REMOVED AND INSTALLED
TOGETHER. THE MANIFOLDS USE A COMMON
GASKET AT THE CYLINDER HEAD.
(1) Disconnect the battery negative cable.
(2) Remove air cleaner inlet hose from the resona-
tor assembly.
(3) Remove the air cleaner assembly.
(4) Remove the throttle cable, vehicle speed control
cable (if equipped) and the transmission line pres-
sure cable (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - AW4/THROTTLE VALVE
CABLE - REMOVAL).
(5) Disconnect the following electrical connections
and secure their harness out of the way:
²Throttle Position Sensor
²Idle Air Control Motor
²Coolant Temperature Sensor (at thermostat
housing)
²Intake Air Temperature Sensor
²Oxygen Sensor
²Crank Position Sensor
²Six (6) Fuel Injector Connectors
²Manifold Absolute Pressure (MAP) Sensor.
(6) Disconnect HVAC, and Brake Booster vacuum
supply hoses at the intake manifold.
(7) Perform the fuel pressure release procedure.
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(8) Disconnect and remove the fuel system supply
line from the fuel rail assembly.
(9) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(10) Remove the power steering pump from the
intake manifold and set aside.
(11) Raise the vehicle.
(12) Disconnect the exhaust pipes from the engine
exhaust manifolds.
(13) Lower the vehicle.
(14) Remove the intake manifold and exhaust
manifold bolts and manifolds (Fig. 84).
INSTALLATION
If the manifold is being replaced, ensure all the fit-
ting, etc. are transferred to the replacement mani-
fold.
(1) Install a new engine exhaust/intake manifold
gasket over the alignment dowels on the cylinder
head.
(2) Position the engine exhaust manifolds to the
cylinder head. Install fastener Number 3 and finger
tighten at this time (Fig. 84).
Fig. 83 Intake Manifold 4.0L Engine
WJENGINE - 4.0L 9 - 57
OIL PUMP (Continued)

(3) Install intake manifold on the cylinder head
dowels.
(4) Install washer and fastener Numbers 1, 2, 4, 5,
8, 9, 10 and 11 (Fig. 84).
(5) Install washer and fastener Numbers 6 and 7
(Fig. 84).
(6) Tighten the fasteners in sequence and to the
specified torque (Fig. 84).
²Fastener Numbers 1 through 5ÐTighten to 33
N´m (24 ft. lbs.) torque.
²Fastener Numbers 6 and 7ÐTighten to 31 N´m
(23 ft. lbs.) torque.
²Fastener Numbers 8 through 11ÐTighten to 33
N´m (24 ft. lbs.) torque.
(7) Install the power steering pump to the intake
manifold.
(8) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(9) Install the fuel system supply line to the fuel
rail assembly.
(10) Connect all electrical connections on the
intake manifold.
(11) Connect the vacuum hoses previously
removed.
(12) Install throttle cable, vehicle speed control
cable (if equipped).
(13) Install the transmission line pressure cable (if
equipped) (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - AW4/THROTTLE VALVE
CABLE - INSTALLATION).
(14) Install air cleaner assembly.
(15) Connect air inlet hose to the resonator assem-
bly.
(16) Raise the vehicle.
(17) Connect the exhaust pipes to the engine
exhaust manifolds. Tighten the bolts to 31 N´m (23
ft. lbs.)
(18) Lower the vehicle.(19) Connect the battery negative cable.
(20) Start the engine and check for leaks.
EXHAUST MANIFOLD
DESCRIPTION
The two exhaust manifolds (Fig. 85) are log style
and are made of high silicon molybdenum cast iron.
The exhaust manifolds share a common gasket with
the intake manifold. The exhaust manifolds also
incorporate ball flange outlets for improved sealing
and strain free connections.
REMOVAL
The intake and engine exhaust manifolds on the
4.0L engine must be removed together. The manifolds
use a common gasket at the cylinder head.
(Refer to 9 - ENGINE/MANIFOLDS/INTAKE
MANIFOLD - REMOVAL).
INSTALLATION
(1) The exhaust manifold and the intake manifold
must be installed together using a common gasket.
(2) (Refer to 9 - ENGINE/MANIFOLDS/INTAKE
MANIFOLD - INSTALLATION).
TIMING BELT / CHAIN
COVER(S)
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the vibration damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL).
(3) Remove the fan, hub assembly and fan shroud
(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
REMOVAL).
(4) Remove the accessory drive brackets that are
attached to the timing case cover.
(5) Remove the A/C compressor (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - REMOVAL) (if equipped) and gen-
erator bracket assembly from the engine cylinder
head and move to one side.
(6) Remove the oil pan-to-timing case cover bolts
and timing case cover-to-cylinder block bolts.
(7) Remove the timing case cover and gasket from
the engine.
(8) Pry the crankshaft oil seal from the front of the
timing case cover (Fig. 86).
INSTALLATION
Clean the timing case cover, oil pan and cylinder
block gasket surfaces.
Fig. 84 Intake and Exhaust Manifolds Installation
9 - 58 ENGINE - 4.0LWJ
INTAKE MANIFOLD (Continued)

ENGINE - 4.7L
TABLE OF CONTENTS
page page
ENGINE - 4.7L
DESCRIPTIONÐ4.7L ENGINE.............63
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION...........64
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - PERFORMANCE...........65
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - MECHANICAL.............66
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - LUBRICATION.............67
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE.............68
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE......69
STANDARD PROCEDURE
STANDARD PROCEDURE - REPAIR
DAMAGED OR WORN THREADS.........70
STANDARD PROCEDURE - FORM-IN-
PLACE GASKETS AND SEALERS.........70
STANDARD PROCEDURE - ENGINE
GASKET SURFACE PREPARATION........70
STANDARD PROCEDURE - ENGINE CORE
AND OIL GALLERY PLUGS..............71
REMOVAL.............................71
INSTALLATION.........................73
SPECIFICATIONS
4.7L ENGINE.........................74
SPECIFICATIONS - 4.7L H.O. ENGINE.....77
TORQUE............................79
SPECIAL TOOLS
4.7L ENGINE.........................80
AIR CLEANER ELEMENT
REMOVAL - 4.7L........................83
INSTALLATION - 4.7L....................83
AIR CLEANER HOUSING
REMOVAL - 4.7L........................84
INSTALLATION - 4.7L....................84
CYLINDER HEAD - LEFT
DESCRIPTION
DESCRIPTION - CYLINDER HEAD........84
DESCRIPTION - VALVE GUIDES..........84
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - HYDRAULIC
LASH ADJUSTER.....................84
DIAGNOSIS AND TESTINGÐCYLINDER
HEAD GASKET.......................85
REMOVAL.............................85
CLEANING............................86
INSPECTION..........................87INSTALLATION.........................87
CAMSHAFT(S) - LEFT
DESCRIPTION.........................88
REMOVAL.............................89
INSTALLATION.........................90
CYLINDER HEAD COVER(S) - LEFT
DESCRIPTION.........................93
REMOVAL - LEFT SIDE..................93
CLEANING............................93
INSTALLATIONÐLEFT SIDE...............93
INTAKE/EXHAUST VALVES & SEATS
DESCRIPTION.........................94
STANDARD PROCEDUREÐREFACING......94
REMOVAL.............................94
INSTALLATION.........................95
ROCKER ARM / ADJUSTER ASSEMBLY
DESCRIPTION.........................96
REMOVAL.............................96
INSTALLATION.........................96
VALVE SPRINGS
DESCRIPTION.........................97
VALVE STEM SEALS
DESCRIPTION.........................97
CYLINDER HEAD - RIGHT
DESCRIPTION
DESCRIPTION - CYLINDER HEAD........97
DESCRIPTION - VALVE GUIDES..........97
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐCYLINDER
HEAD GASKET.......................97
DIAGNOSIS AND TESTING - HYDRAULIC
LASH ADJUSTER.....................98
REMOVAL.............................98
CLEANING............................99
INSPECTION..........................99
INSTALLATION.........................99
CAMSHAFT(S) - RIGHT
DESCRIPTION........................100
REMOVAL............................100
INSTALLATION........................102
CYLINDER HEAD COVER(S) - RIGHT
DESCRIPTION........................104
REMOVAL - RIGHT SIDE................104
CLEANING...........................104
INSTALLATION - RIGHT SIDE.............104
INTAKE/EXHAUST VALVES & SEATS
DESCRIPTION........................104
STANDARD PROCEDUREÐREFACING.....105
REMOVAL............................105
INSTALLATION........................106
WJENGINE - 4.7L 9 - 61

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)ÐPERFORMANCE 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).
Fig. 1 Engine Identification Location
1 - VEHICLE VIN NUMBER LOCATION
2 - CYLINDER BLOCK RIGHT HAND SIDE
3 - CYLINDER BORE #2
9 - 64 ENGINE - 4.7LWJ
ENGINE - 4.7L (Continued)