2002 JEEP GRAND CHEROKEE Bus

8W-97 POWER DISTRIBUTION
TABLE OF CONTENTS
page page
POWER DISTRIBUTION
DESCRIPTION..........................1
OPERATION............................1
SPECIAL TOOLS
POWER DISTRIBUTION SYSTEMS.........2
CIGAR LIGHTER OUTLET
DESCRIPTION..........................2
OPERATION............................2
DIAGNOSIS AND TESTING - CIGAR LIGHTER
OUTLET.............................2
CIGAR LIGHTER OUTLET DOOR SPRING
REMOVAL.............................3
INSTALLATION..........................3
IOD FUSE
DESCRIPTION..........................3
OPERATION............................4
REMOVAL.............................4
INSTALLATION..........................4
JUNCTION BLOCK
DESCRIPTION..........................5
OPERATION............................5
REMOVAL.............................5
INSTALLATION..........................6
POWER DISTRIBUTION CENTER
DESCRIPTION..........................7
OPERATION............................8
REMOVAL.............................8
DISASSEMBLY
POWER DISTRIBUTION CENTER
DISASSEMBLY........................9ASSEMBLY
POWER DISTRIBUTION CENTER
ASSEMBLY..........................11
INSTALLATION.........................12
POWER OUTLET
DESCRIPTION - FRONT POWER OUTLET....12
OPERATION - FRONT POWER OUTLET......12
DIAGNOSIS AND TESTING - POWER OUTLET . 12
REMOVAL.............................13
INSTALLATION.........................13
POWER OUTLET RELAY
DESCRIPTION.........................13
OPERATION...........................14
DIAGNOSIS AND TESTING - POWER OUTLET
RELAY..............................14
REMOVAL.............................15
INSTALLATION.........................15
IOD WIRE HARNESS CONNECTOR
DESCRIPTION.........................15
OPERATION...........................15
FUSE COVER
REMOVAL.............................16
INSTALLATION.........................16
REAR POWER OUTLET
DESCRIPTION - REAR POWER OUTLET.....16
OPERATION - REAR POWER OUTLET.......17
DIAGNOSIS AND TESTING - REAR POWER
OUTLET............................17
REMOVAL.............................17
INSTALLATION.........................18
POWER DISTRIBUTION
DESCRIPTION
This group covers the various standard and
optional power distribution components used on this
model. The power distribution system for this vehicle
consists of the following components:
²Power Distribution Center (PDC)
²Junction Block (JB)
²Power Outlets
The power distribution system also incorporates
various types of circuit control and protection fea-
tures, including:
²Automatic resetting circuit breakers
²Blade-type fuses
²Bus bars
²Cartridge fuses²Circuit splice blocks
²Flashers
²Fusible links
²Standard and Micro-Relays
Following are general descriptions of the major
components in the power distribution system. See the
owner's manual in the vehicle glove box for more
information on the features and use of all of the
power distribution system components. Refer to Wir-
ing Diagrams for complete circuit diagrams.
OPERATION
The power distribution system for this vehicle is
designed to provide safe, reliable, and centralized dis-
tribution points for the electrical current required to
operate all of the standard and optional factory-in-
stalled electrical and electronic powertrain, chassis,
safety, security, comfort and convenience systems. At
WJ8W-97 POWER DISTRIBUTION 8W - 97 - 1

(5) Reconnect the right and left body wire harness
bulkhead connectors to the connector receptacles
located near the center of the JB.
(6) Install and tighten the screws that secure the
right and left body wire harness bulkhead connectors
to the connector receptacles located near the center
of the JB. Tighten the screws to 2.2 N´m (20 in. lbs.).
(7) Reconnect the fused B(+) and the IOD wire
harness connectors to the connector receptacles
located near the bottom of the JB.
(8) Reach behind the JB to reconnect the instru-
ment panel wire harness bulkhead connector to the
connector receptacle located near the top of the JB.
(9) Install and tighten the screw that secures the
instrument panel wire harness bulkhead connector to
the connector receptacle located near the top of the
JB. Tighten the screw to 2.2 N´m (20 in. lbs.).
(10)
Reach behind the JB to reconnect the two
instrument panel wire harness connectors to the BCM
connector receptacles located near the bottom of the JB.
(11) Install the steering column opening cover onto
the instrument panel. Refer toSteering Column
Opening Coverin Body for the location of the steer-
ing column opening cover installation procedures.
(12)
Install the fuse cover onto the bottom of the JB.
(13) Reconnect the battery negative cable.
POWER DISTRIBUTION
CENTER
DESCRIPTION
All of the electrical current distributed throughout
this vehicle is directed through the standard equip-ment Power Distribution Center (PDC) (Fig. 7). The
molded plastic PDC housing is located in the right
front corner of the engine compartment, between the
battery and the right front inner fender shield. The
PDC houses up to fifteen maxi-type cartridge fuses,
which replace all in-line fusible links. The PDC also
houses up to thirteen blade-type mini fuses, and up
to ten International Standards Organization (ISO)
relays (two standard-type and eight micro-type).
The PDC housing is secured in the engine compart-
ment at three points. Integral mounts on both sides of
the PDC housing engage and latch to stanchions that
are integral to the molded plastic battery support. The
PDC is integral to the right headlamp and dash wire
harness, which exits from the bottom of the PDC hous-
ing. The PDC housing has a molded plastic cover that
includes two integral latches at the front and pivot
hooks at the back that snap over a hinge pin on the
rear of the PDC housing. The PDC cover is easily
opened or removed for service access and has a conve-
nient fuse and relay layout map integral to the inside
surface of the cover to ensure proper component identi-
fication. A fuse puller is also stored on the inside of the
PDC cover.
The PDC cover, the PDC housing lower cover, the
PDC relay wedges, the PDC relay cassettes and the
PDC B(+) terminal stud module are available for ser-
vice replacement. The PDC main housing unit, the
fuse wedges and the bus bars cannot be repaired and
Fig. 6 Junction Block
1 - SCREW (2)
2 - DRIVER SIDE COURTESY LAMP
3 - JUNCTION BLOCK
4 - 16 WAY DATA LINK CONNECTOR
Fig. 7 Power Distribution Center Location
1 - RIGHT FENDER
2 - BATTERY
3 - POWER DISTRIBUTION CENTER
4 - COVER
WJ8W-97 POWER DISTRIBUTION 8W - 97 - 7
JUNCTION BLOCK (Continued)

are only serviced as a unit with the right headlamp
and dash wire harness. If the PDC main housing
unit, fuse wedges or the bus bars are faulty or dam-
aged, the right headlamp and dash wire harness unit
must be replaced.
OPERATION
All of the current from the battery and the generator
output enters the PDC through two cables and a single
two-holed eyelet that is secured with nuts to the two
PDC B(+) terminal studs just inside the front end of the
PDC housing. The PDC cover is unlatched and opened
to access the battery and generator output connection
B(+) terminal studs, the fuses or the relays. Internal
connection of all of the PDC circuits is accomplished by
an intricate combination of hard wiring and bus bars.
Refer toPower Distribution
in Wiring Diagrams for
the location of complete PDC circuit diagrams.
REMOVAL
The Power Distribution Center (PDC) main housing
unit, the PDC fuse wedges and the PDC bus bars can-
not be repaired and are only serviced as a unit with the
right headlamp and dash wire harness. If the PDC
main housing unit, the fuse wedges or the bus bars are
faulty or damaged, the entire PDC and right headlamp
and dash wire harness unit must be replaced.
(1)Disconnect and isolate the battery negative cable.
(2) Disconnect each of the right headlamp and
dash wire harness connectors. Refer toConnector
Locationsin Wiring Diagrams for the location of
more information on the right headlamp and dash
wire harness connector locations.
(3) Remove all of the fasteners that secure each of
the right headlamp and dash wire harness ground
eyelets to the vehicle body and chassis components.
Refer toConnector Locationsin Wiring Diagrams
for the location of more information on the ground
eyelet locations.
(4) Disengage each of the retainers that secure the
right headlamp and dash wire harness to the vehicle
body and chassis components. Refer toConnector
Locationsin Wiring Diagrams for the location of
more information on the right headlamp and dash
wire harness retainer locations.
(5) Unlatch and open the PDC cover.
(6) Remove the two nuts that secure the two-holed
eyelet of the battery wire harness PDC take outs to
the PDC B(+) terminal studs (Fig. 8).
(7) Remove the battery wire harness PDC take out
eyelet from the B(+) terminal studs.
(8) Disengage the latches on the PDC housing
mounts from the tabs on the PDC mounting stan-
chions of the battery support, and pull the PDC
housing upward to disengage the mounts from the
stanchions (Fig. 9).
Fig. 8 Power Distribution Center Connections
1 - PDC COVER
2 - NUT (2)
3 - EYELET
4 - B(+) TERMINAL STUDS
Fig. 9 Power Distribution Center Remove/Install
1 - POWER DISTRIBUTION CENTER
2 - MOUNTS
3 - STANCHIONS (3)
4 - BATTERY SUPPORT
8W - 97 - 8 8W-97 POWER DISTRIBUTIONWJ
POWER DISTRIBUTION CENTER (Continued)

(9) Remove the PDC and the right headlamp and
dash wire harness from the engine compartment as a
unit.
DISASSEMBLY
POWER DISTRIBUTION CENTER DISASSEMBLY
PDC HOUSING LOWER COVER REMOVAL
The Power Distribution Center (PDC) cover, the
PDC housing lower cover, the PDC relay wedges, the
PDC relay cassettes and the PDC B(+) terminal stud
module are available for service replacement. The
PDC cover can be simply unlatched and removed
from the PDC housing without the PDC being
removed or disassembled. Service of the remaining
PDC components requires that the PDC be removed
from its mounting and disassembled. Refer toWiring
Repairin Wiring Diagrams for the location of the
wiring repair procedures.
(1) Remove the battery from the battery support.
Refer toBattery Systemfor the location of the bat-
tery removal procedures.
(2) Unlatch and remove the cover from the PDC.
(3) Remove the two nuts that secure the two-holed
eyelet of the battery wire harness PDC take out to
the B(+) terminal studs near the front of the PDC.
(4) Remove the battery wire harness PDC take out
eyelet from the two PDC B(+) terminal studs.
(5) Disengage the latches on the PDC housing
mounts from the tabs on the PDC mounting stan-
chions on the battery support, and pull the PDC
housing upward to disengage the mounts from the
stanchions.
(6) Where the right headlamp and dash wire har-
ness exits the PDC, remove the tape that secures the
wire harness to the trough formation on the PDC
housing lower cover.
(7) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the latches on each side
and the front of the PDC housing that secure the
housing lower cover to the PDC and remove the
housing lower cover (Fig. 10).
PDC B+ TERMINAL MODULE REMOVAL
The Power Distribution Center (PDC) cover, the
PDC housing lower cover, the PDC relay wedges, the
PDC relay cassettes and the PDC B(+) terminal stud
module are available for service replacement. The
PDC cover can be simply unlatched and removed
from the PDC housing without the PDC being
removed or disassembled. Service of the remaining
PDC components requires that the PDC be removed
from its mounting and disassembled. Refer toWiring
Repairin Wiring Diagrams for the location of the
wiring repair procedures.(1) Remove the PDC housing lower cover.
(2) From the top of the PDC housing, use a small
screwdriver or a terminal pick tool (Special Tool Kit
6680) to release the two latches that secure the B(+)
terminal module in the PDC.
(3) Gently and evenly press the two B(+) terminal
studs down through the bus bar in the PDC.
(4) From the bottom of the PDC housing, remove
the B(+) terminal module from the PDC.
PDC RELAY WEDGE REMOVAL
The Power Distribution Center (PDC) cover, the
PDC housing lower cover, the PDC relay wedges, the
PDC relay cassettes and the PDC B(+) terminal stud
module are available for service replacement. The
PDC cover can be simply unlatched and removed
from the PDC housing without the PDC being
removed or disassembled. Service of the remaining
PDC components requires that the PDC be removed
from its mounting and disassembled. Refer toWiring
Repairin Wiring Diagrams for the location of the
wiring repair procedures.
(1) Remove the PDC housing lower cover.
(2) Remove each of the relays from the PDC relay
wedge to be removed.
(3) From the bottom of the PDC housing, use a
small screwdriver or a terminal pick tool (Special
Fig. 10 PDC Housing Lower Cover Remove/Install -
Typical
1 - TROUGH FORMATION
2 - LATCHES (5)
3 - PDC HOUSING LOWER COVER
4 - WIRE HARNESS
WJ8W-97 POWER DISTRIBUTION 8W - 97 - 9
POWER DISTRIBUTION CENTER (Continued)

CAUTION: Do not remove the wiring and terminals
from the terminal cavities of the faulty PDC relay
cassette at this time. Refer to the Assembly proce-
dure that follows for the proper procedures for
transferring the wiring and terminals to the replace-
ment PDC relay cassette.
ASSEMBLY
POWER DISTRIBUTION CENTER ASSEMBLY
PDC B(+) TERMINAL MODULE INSTALLATION
(1) From the bottom of the PDC housing, align and
insert the B(+) terminal module into the PDC.
(2) From the bottom of the PDC housing, align and
insert the two studs of the PDC B(+) terminal mod-
ule through the bus bar in the PDC.
(3) From the bottom of the PDC housing, press the
B(+) terminal module gently and evenly into the PDC
until both of the latches are fully engaged.
(4) Install the PDC housing lower cover.
RELAY WEDGE INSTALLATION
(1) From the top of the PDC housing, align and
insert the PDC relay wedge latch arms into the cor-
rect cavities in the relay cassette.
(2) Gently and evenly press the PDC relay wedge
down into the relay cassette until both of the latches
are fully engaged.
(3) Install each of the removed relays into the
proper cavities of the PDC relay wedge.
(4) Install the PDC housing lower cover.
RELAY CASSETTE INSTALLATION
(1) Move the faulty PDC relay cassette with its
wiring away from the bottom of the PDC housing far
enough to allow the replacement relay cassette to be
installed into the PDC.
(2) Using the faulty relay cassette as a guide, be
certain that the replacement relay cassette is cor-
rectly oriented before installing it into the PDC hous-
ing.
(3) From the bottom of the PDC housing, align and
insert the replacement relay cassette into the PDC.
Press the relay cassette up into the PDC until both
of the latches are fully engaged.
CAUTION: Proper care must be taken to be certain
that the wiring and terminals from the faulty PDC
relay cassette are installed in the correct terminal
cavities of the replacement relay cassette. To pre-
vent mistakes it is recommended that the wiring
and terminals be removed from the faulty relay cas-
sette one cavity at a time, repaired or spliced as
necessary, then installed securely into the correctcavity of the replacement relay cassette. If you are
not absolutely certain into which cavity a terminal
should be installed, refer to Power Distribution in
the index of this service manual for the location of
complete circuit diagrams covering the PDC.
(4) While pulling gently on the wire from the bot-
tom of the faulty PDC relay cassette, use a terminal
pick tool (Special Tool Kit 6680) from the top of the
relay cassette to release the latch that secures the
terminal in the relay cassette terminal cavity (Fig.
14).
(5) From the bottom of the faulty PDC relay cas-
sette, remove the wire and terminal from the relay
cassette terminal cavity.
(6) Make all necessary repairs and splices to the
wire for the removed terminal. Refer toWiring
Repairin Wiring Diagrams for the location of the
wiring repair procedures.
(7) From the bottom of the PDC housing, align and
insert the removed wire and terminal into the correct
terminal cavity of the replacement relay cassette.
Push the wire and terminal up into the relay cassette
terminal cavity until it is fully engaged by the latch.
(8) Repeat Step 4, Step 5, Step 6 and Step 7 one
wire and terminal at a time until each of the wires
and terminals have been transferred from the faulty
PDC relay cassette into the replacement relay cas-
sette.
(9) Install the PDC relay wedge into the replace-
ment PDC relay cassette.
Fig. 14 PDC Relay Cassette Terminal Remove/Install
- Typical
1 - TERMINAL CAVITIES (TYPICAL)
2 - PDC RELAY CASSETTE (TYPICAL)
3 - TERMINAL LATCHES (TYPICAL)
4 - FROM SPECIAL TOOL KIT 6680
WJ8W-97 POWER DISTRIBUTION 8W - 97 - 11
POWER DISTRIBUTION CENTER (Continued)

PDC LOWER COVER INSTALLATION
(1) Align the PDC housing lower cover on the bot-
tom of the PDC.
(2) Evenly press the lower cover into place until
latches are fully engaged.
(3) Where the right headlamp and dash harness
enters the PDC, tape the harness securely to the
trough formation on the PDC lower cover.
(4) Install the PDC in its mounting location on the
battery support.
(5) Install the battery wire harness over the two
PDC B+ terminal studs. Torque the nuts to 11.3 N´m
(100 in. lbs.).
(6) Install the battery. Refer to Battery System for
the procedure.
(7) Install the PDC cover.
INSTALLATION
The Power Distribution Center (PDC) main hous-
ing unit, the PDC fuse wedges and the PDC bus bars
cannot be repaired and are only serviced as a unit
with the right headlamp and dash wire harness. If
the PDC main housing unit, the fuse wedges or the
bus bars are faulty or damaged, the entire PDC and
right headlamp and dash wire harness unit must be
replaced.
(1) Position the PDC and the right headlamp and
dash wire harness unit in the engine compartment.
(2) Engage the PDC housing mounts with the
stanchions of the battery support and push the unit
downward until the mount latches fully engage the
mounting tabs on the stanchions.
(3) Install the two-holed eyelet of the battery wire
harness PDC take outs onto the two PDC B(+) termi-
nal studs.
(4) Install and tighten the nuts that secure the
eyelet of the battery wire harness PDC take outs to
the B(+) terminal studs. Tighten the nuts to 11.3
N´m (100 in. lbs.).
(5) Engage each of the retainers that secure the
right headlamp and dash wire harness to the vehicle
body and chassis components. Refer toConnector
Locationsin Wiring Diagrams for the location of
more information on the right headlamp and dash
wire harness retainer locations.
(6) Install all of the fasteners that secure each of
the right headlamp and dash wire harness ground
eyelets to the vehicle body and chassis components.
Refer toConnector Locationsin Wiring Diagrams
for the location of more information on the ground
eyelet locations.
(7) Reconnect each of the right headlamp and dash
wire harness connectors. Refer toConnector Loca-
tionsin Wiring Diagrams for the location of more
information on the right headlamp and dash wire
harness connector locations. For connectors securedwith screws, tighten the screws to 4.3 N´m (38 in.
lbs.).
(8) Reconnect the battery negative cable.
POWER OUTLET
DESCRIPTION - FRONT POWER OUTLET
An accessory power outlet is standard equipment
on this model. The power outlet is installed in the
instrument panel center lower bezel, which is located
near the bottom of the instrument panel center stack
area, below the heater and air conditioner controls.
The power outlet base is secured by a snap fit within
the center lower bezel. A hinged door with an over-
center spring flips closed to conceal and protect the
power outlet base when the power outlet is not being
used, and flips open below the center lower bezel
while the power outlet is in use.
The power outlet receptacle unit and the power
outlet door are each available for service replace-
ment.
OPERATION - FRONT POWER OUTLET
The power outlet base or receptacle shell is con-
nected to ground, and an insulated contact in the
bottom of the shell is connected to battery current.
The power outlet receives battery voltage from a fuse
in the junction block at all times.
While the power outlet is very similar to a cigar
lighter base unit, it does not include the two small
spring-clip retainers inside the bottom of the recepta-
cle shell that are used to secure the cigar lighter
heating element to the insulated contact.
DIAGNOSIS AND TESTING - POWER OUTLET
For complete circuit diagrams, refer toHorn/Ci-
gar Lighter/Power Outletin Wiring Diagrams.
WARNING: REFER TO RESTRAINTS BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Check the fused B(+) fuse in the junction block.
If OK, go to Step 2. If not OK, repair the shorted cir-
cuit or component as required and replace the faulty
fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the junction block. If OK, go to Step 3. If not OK,
repair the open fused B(+) circuit to the Power Dis-
tribution Center (PDC) fuse as required.
(3) Open the power outlet door. Check for continu-
ity between the inside circumference of the power
8W - 97 - 12 8W-97 POWER DISTRIBUTIONWJ
POWER DISTRIBUTION CENTER (Continued)

ENGINE
TABLE OF CONTENTS
page page
ENGINE - 4.0L............................ 1ENGINE - 4.7L........................... 61
ENGINE - 4.0L
TABLE OF CONTENTS
page page
ENGINE - 4.0L
DESCRIPTION..........................2
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION............3
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - PERFORMANCE............4
DIAGNOSIS AND TESTINGÐ ENGINE
DIAGNOSIS - MECHANICAL..............6
DIAGNOSIS AND TESTINGÐCYLINDER
COMPRESSION PRESSURE..............8
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE.......8
DIAGNOSIS AND TESTINGÐREAR SEAL
AREA LEAKS..........................9
STANDARD PROCEDURE
STANDARD PROCEDURE - FORM-IN-
PLACE GASKETS AND SEALERS..........9
STANDARD PROCEDURE - REPAIR
DAMAGED OR WORN THREADS.........10
STANDARD PROCEDUREÐHYDROSTATIC
LOCK...............................10
STANDARD PROCEDURE - CYLINDER
BORE HONING.......................10
STANDARD PROCEDURE - ENGINE CORE
AND OIL GALLERY PLUGS..............11
REMOVAL.............................11
INSTALLATION.........................13
SPECIFICATIONS
ENGINE - 4.0L........................14
TORQUE - 4.0L ENGINE................17
AIR CLEANER ELEMENT
REMOVAL - 4.0L........................18
INSTALLATION - 4.0L....................19
AIR CLEANER HOUSING
REMOVAL - 4.0L........................19
INSTALLATION - 4.0L....................19CYLINDER HEAD
DESCRIPTION.........................19
REMOVAL.............................19
CLEANING............................21
INSPECTION..........................21
INSTALLATION.........................21
CYLINDER HEAD COVER(S)
DESCRIPTION.........................22
REMOVAL.............................22
CLEANING............................23
INSPECTION..........................23
INSTALLATION.........................23
INTAKE/EXHAUST VALVES & SEATS
DESCRIPTION.........................23
STANDARD PROCEDURE - VALVE SERVICE . . 23
REMOVAL.............................25
INSTALLATION.........................25
ROCKER ARM / ADJUSTER ASSEMBLY
DESCRIPTION.........................26
OPERATION...........................26
REMOVAL.............................26
CLEANING............................26
INSPECTION..........................27
INSTALLATION.........................27
VALVE STEM SEALS
DESCRIPTION.........................27
VALVE SPRINGS
DESCRIPTION.........................28
STANDARD PROCEDURE - VALVE SPRING
TENSION TEST.......................28
REMOVAL.............................28
INSTALLATION.........................29
ENGINE BLOCK
CLEANING............................30
INSPECTION..........................30
CAMSHAFT & BEARINGS
DESCRIPTION.........................30
WJENGINE 9 - 1

REMOVAL
REMOVAL - CAMSHAFT BEARINGS.......31
REMOVAL - CAMSHAFT................31
INSPECTION
INSPECTION - CAMSHAFT BEARINGS.....31
INSPECTION - CAMSHAFT..............31
INSTALLATION
INSTALLATION - CAMSHAFT BEARINGS . . . 32
INSTALLATION - CAMSHAFT............32
CONNECTING ROD BEARINGS
STANDARD PROCEDURE - FITTING
CONNECTING ROD BEARINGS..........33
CRANKSHAFT
DESCRIPTION.........................35
CRANKSHAFT MAIN BEARINGS
STANDARD PROCEDURE - FITTING
CRANKSHAFT MAIN BEARINGS..........36
REMOVAL.............................39
INSPECTION..........................40
INSTALLATION.........................40
CRANKSHAFT OIL SEAL - FRONT
REMOVAL.............................41
INSTALLATION.........................41
CRANKSHAFT OIL SEAL - REAR
REMOVAL.............................42
INSTALLATION.........................42
HYDRAULIC LIFTERS
DESCRIPTION.........................43
REMOVAL.............................43
CLEANING............................43
INSPECTION..........................43
INSTALLATION.........................43
PISTON & CONNECTING ROD
DESCRIPTION.........................44
STANDARD PROCEDURE - PISTON FITTING . 44
REMOVAL.............................45
INSTALLATION.........................46
PISTON RINGS
STANDARD PROCEDURE - PISTON RING
FITTING.............................47
VIBRATION DAMPER
REMOVAL.............................49
INSTALLATION.........................49STRUCTURAL SUPPORT
REMOVAL.............................49
INSTALLATION.........................50
LUBRICATION
DESCRIPTION.........................50
OPERATION...........................50
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE OIL
PRESSURE..........................51
DIAGNOSIS AND TESTING - ENGINE OIL
LEAK...............................51
OIL
STANDARD PROCEDURE - ENGINE OIL
SERVICE............................53
OIL FILTER
REMOVAL.............................53
INSTALLATION.........................54
OIL PAN
DESCRIPTION.........................54
REMOVAL.............................54
INSTALLATION.........................55
ENGINE OIL PRESSURE SENSOR
DESCRIPTION.........................56
OPERATION...........................56
OIL PUMP
REMOVAL.............................56
INSTALLATION.........................57
INTAKE MANIFOLD
DESCRIPTION.........................57
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKAGE..................57
REMOVAL.............................57
INSTALLATION.........................57
EXHAUST MANIFOLD
DESCRIPTION.........................58
REMOVAL.............................58
INSTALLATION.........................58
TIMING BELT / CHAIN COVER(S)
REMOVAL.............................58
INSTALLATION.........................58
TIMING BELT/CHAIN AND SPROCKETS
REMOVAL.............................60
INSTALLATION.........................60
ENGINE - 4.0L
DESCRIPTION
The 4.0 Liter (242 CID) six-cylinder engine is an
In-line, lightweight, overhead valve engine. This
engine is designed for unleaded fuel.
The engine cylinder head has dual quench-type
combustion chambers that create turbulence and fast
burning of the air/fuel mixture. This results in better
fuel economy.
The cylinders are numbered 1 through 6 from front
to rear. The firing order is 1-5-3-6-2-4 (Fig. 1).The crankshaft rotation is clockwise, when viewed
from the front of the engine. The crankshaft rotates
within seven main bearings. The camshaft rotates
within four bearings.
The engine Build Date Code is located on a
machined surface on the right side of the cylinder
block between the No.2 and No.3 cylinders (Fig. 2).
The digits of the code identify:
²1st DigitÐThe year (8 = 1998).
²2nd & 3rd DigitsÐThe month (01 - 12).
²4th & 5th DigitsÐThe engine type/fuel system/
compression ratio (MX = A 4.0 Liter (242 CID) 8.7:1
compression ratio engine with a multi-point fuel
injection system).
9 - 2 ENGINE - 4.0LWJ