2002 JEEP LIBERTY Remove rear seat

(7) Pull lightly outward on the top of the washer
pump/motor housing away from the washer reservoir
far enough to disengage the snap post on the top of
the motor from the receptacle in the reservoir (Fig.
20).
(8) Pull the washer pump/motor unit straight out
from the washer reservoir far enough to disengage
the barbed pump inlet nipple from the rubber grom-
met seal in the reservoir.
(9) Disconnect the headlamp and dash wire har-
ness connector from the washer pump/motor unit
connector receptacle on the top of the motor housing
(Fig. 21).
(10) Disconnect the two washer hoses from the two
washer pump/motor unit outlet nipples.
(11) Remove washer pump/motor unit through the
access hole at the front of the right front fender
wheel house splash shield.
(12) Remove the rubber grommet seal from the
washer reservoir and discard.
INSTALLATION
(1) Install a new rubber grommet seal into the
washer pump mounting hole in the washer reservoir.
Always use a new rubber grommet seal on the reser-
voir.
(2) Position the barbed inlet nipple of the washer
pump to the rubber grommet seal in the washer res-
ervoir (Fig. 20).
(3) Using hand pressure, press on the washer
pump/motor unit firmly and evenly until the barbed
inlet nipple is fully seated in the rubber grommet
seal in the washer reservoir mounting hole.(4) Align the washer pump/motor snap post on the
top of the motor housing with the snap post recepta-
cle in the washer reservoir.
(5) Using hand pressure, press firmly and evenly
on the top of washer pump/motor unit until the snap
post snaps into the washer reservoir receptacle.
(6) Reconnect the headlamp and dash wire harness
connector for the washer pump/motor unit to the con-
nector receptacle on the top of the motor housing
(Fig. 21).
(7) Reconnect the front and rear washer hoses to
the two barbed pump outlet nipples. Be certain that
the hose in the trough of the reservoir behind the
pump is connected to the rear nipple, and the hose in
the trough in front of the pump is connected to the
front nipple.
(8) Lower and snap shut the cover over the access
hole at the front of the right front wheel house
splash shield.
(9) Lower vehicle.
(10) Reconnect the battery negative cable.
(11) Refill the washer reservoir with clean washer
fluid.
Fig. 20 Washer Pump/Motor Remove/Install
1 - WASHER RESERVOIR
2 - SNAP POST
3 - INLET NIPPLE
4 - GROMMET SEAL
5 - WASHER PUMP/MOTORFig. 21 Washer Pump/Motor Connections
1 - WASHER RESERVOIR
2 - WIRE HARNESS
3 - WASHER PUMP/MOTOR
4 - FRONT WASHER HOSE
5 - REAR WASHER HOSE
6 - WASHER FLUID LEVEL SWITCH
8R - 20 FRONT WIPERS/WASHERSKJ
WASHER PUMP/MOTOR (Continued)

mation includes wiring diagrams, proper wire and
connector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
SIDE CURTAIN AIRBAG, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE SYSTEM CAPACITOR TO DISCHARGE BEFORE
PERFORMING FURTHER DIAGNOSIS OR SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO
TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Check that the interior lighting switch on the
left (lighting) control stalk of the multi-function
switch is not in the dome lamp disable position. With
all four doors and the tailgate closed, open the rear
flip-up glass. The interior lamps should light. Close
the rear flip-up glass. Note whether the interior
lamps remain lighted. They should turn off after
about thirty seconds. If OK, go to Step 2. If not OK,
go to Step 9.
(2) Check the fused B(+) fuse (Fuse 17 - 15
ampere) in the Junction Block (JB). If OK, go to Step
3. If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(3) Check for battery voltage at the fused B(+) fuse
(Fuse 17 - 15 ampere) in the JB. If OK, go to Step 4.
If not OK, repair the open fused B(+) circuit between
the JB and the Power Distribution Center (PDC) as
required.
(4) Check the fused ignition switch output (run-
acc) fuse (Fuse 22 - 10 ampere) in the JB. If OK, go
to Step 5. If not OK, repair the shorted circuit or
component as required and replace the faulty fuse.
(5) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run-acc) fuse (Fuse 22 - 10 ampere) in the
JB. If OK, turn the ignition switch to the Off position
and go to Step 6. If not OK, repair the open fused
ignition switch output (run-acc) circuit between the
JB and the ignition switch as required.
(6) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the multi-function switch (Connector
C-2) from the switch connector receptacle. Reconnect
the battery negative cable. Turn the ignition switchto the On position. Check for battery voltage at the
fused ignition switch output (run-acc) circuit cavity of
the instrument panel wire harness connector for the
multi-function switch (Connector C-2). If OK, go to
Step 7. If not OK, repair the open fused ignition
switch output (run-acc) circuit between the multi-
function switch and the JB as required.
(7) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Test the multi-function switch. (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/MULTI-
FUNCTION SWITCH - DIAGNOSIS AND
TESTING). If the multi-function switch tests OK,
reconnect the instrument panel wire harness connec-
tors for the multi-function switch to the switch con-
nector receptacles and go to Step 8. If the multi-
function switch does not test OK, replace the faulty
switch.
(8) Remove the tailgate inner trim panel. Discon-
nect the tailgate wire harness connector for the rear
wiper module from the module connector receptacle.
Check for continuity between the ground circuit cav-
ity of the tailgate wire harness connector for the rear
wiper module and a good ground. There should be
continuity. If OK, go to Step 9. If not OK, repair the
open ground circuit to ground (G312) as required.
(9) Check for continuity between the flip-up glass
ajar switch sense circuit cavity of the tailgate wire
harness connector for the rear wiper module and a
good ground. There should be continuity with the
rear flip-up glass open, and no continuity with the
rear flip-up glass closed. If OK, go to Step 10. If not
OK, repair the open flip-up glass ajar circuit between
the rear wiper module and the flip-up glass ajar
switch as required.
(10) Reconnect the battery negative cable. Check
for battery voltage at the fused B(+) circuit cavity of
the tailgate wire harness connector for the rear wiper
module. If OK, go to Step 11. If not OK, repair the
open fused B(+) circuit between the rear wiper mod-
ule and the JB as required.
(11) Turn the ignition switch to the On position.
Turn the control ring on the right (wiper) control
stalk of the multi-function switch to the Delay posi-
tion. Check for battery voltage at the rear wiper
intermittent driver circuit cavity of the tailgate wire
harness connector for the rear wiper module. If OK,
go to Step 12. If not OK, repair the open rear wiper
intermittent driver circuit between the rear wiper
module and the multi-function switch as required.
(12) Turn the control ring on the right (wiper) con-
trol stalk of the multi-function switch to the On posi-
tion. Check for battery voltage at the rear wiper on
driver circuit cavity of the tailgate wire harness con-
nector for the rear wiper module. If OK, replace the
faulty rear wiper module. If not OK, repair the open
KJREAR WIPERS/WASHERS 8R - 31
REAR WIPERS/WASHERS (Continued)

rear wiper on driver circuit between the rear wiper
module and the multi-function switch as required.
REAR WASHER SYSTEM
The diagnosis found here addresses an electrically
inoperative rear washer system. If the washer pump/
motor operates, but no washer fluid is emitted from
the rear washer nozzle, be certain to check the fluid
level in the reservoir. Also inspect the rear washer
system components as required. (Refer to 8 - ELEC-
TRICAL/REAR WIPERS/WASHERS - INSPECTION).
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
SIDE CURTAIN AIRBAG, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE SYSTEM CAPACITOR TO DISCHARGE BEFORE
PERFORMING FURTHER DIAGNOSIS OR SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO
TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Turn the ignition switch to the On position.
Turn the control ring on the right (wiper) control
stalk of the multi-function switch to the On position.
Check whether the rear wiper system is operating. If
OK, go to Step 2. If not OK, test and repair the rear
wiper system before continuing with these tests.
Refer to REAR WIPER SYSTEM .
(2) Pull the right (wiper) control stalk of the multi-
function switch toward the steering wheel. Check
whether the front washer system is operating. If OK,
test the multi-function switch. (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/MULTI-
FUNCTION SWITCH - DIAGNOSIS AND
TESTING). If the multi-function switch tests OK, go
to Step 3. If the multi-function switch does not test
OK, replace the faulty switch.
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the headlamp and dash wire harness con-
nector for the washer pump/motor unit from the
pump/motor unit connector receptacle. Check for con-
tinuity between the washer pump driver circuit cav-ity of the headlamp and dash wire harness connector
for the washer pump/motor unit and a good ground.
There should be no continuity. If OK, go to Step 4. If
not OK, repair the shorted washer pump driver cir-
cuit between the washer pump/motor unit and the
multi-function switch as required.
(4) Check for continuity between the washer pump
driver circuit cavities of the headlamp and dash wire
harness connector for the washer pump/motor unit
and the instrument panel wire harness connector for
the multi-function switch (Connector C-2). There
should be continuity. If OK, go to Step 5. If not OK,
repair the open washer pump driver circuit between
the washer pump/motor unit and the multi-function
switch as required.
(5) Check for continuity between the washer pump
sense circuit cavity of the headlamp and dash wire
harness connector for the washer pump/motor unit
and a good ground. There should be no continuity. If
OK, go to Step 6. If not OK, repair the shorted
washer pump sense circuit between the washer
pump/motor unit and the multi-function switch as
required.
(6) Check for continuity between the washer pump
sense circuit cavities of the headlamp and dash wire
harness connector for the washer pump/motor unit
and the instrument panel wire harness connector for
the multi-function switch (Connector C-2). There
should be continuity. If OK, replace the faulty washer
pump/motor unit. If not OK, repair the open washer
pump sense circuit between the washer pump/motor
unit and the multi-function switch as required.
CLEANING - REAR WIPER & WASHER SYSTEM
REAR WIPER SYSTEM
The squeegee of a wiper blade exposed to the ele-
ments for a long time tends to lose its wiping effec-
tiveness. Periodic cleaning of the squeegee is
suggested to remove any deposits of salt or road film.
The wiper blade, arm, and rear flip-up glass should
only be cleaned using a sponge or soft cloth and
windshield washer fluid, a mild detergent, or a non-
abrasive cleaner. If the wiper blade continues to
leave streaks, smears, hazing, or beading on the
glass after thorough cleaning of the squeegees and
the glass, the entire wiper blade assembly must be
replaced.
CAUTION: Protect the rubber squeegee of the wiper
blade from any petroleum-based cleaners, solvents,
or contaminants. These products can rapidly deteri-
orate the rubber squeegee.
8R - 32 REAR WIPERS/WASHERSKJ
REAR WIPERS/WASHERS (Continued)

REAR WASHER SYSTEM
The washer system components should be
inspected periodically, not just when washer perfor-
mance problems are experienced. This inspection
should include the following points:
(1) Check for ice or other foreign material in the
washer reservoir. If contaminated, clean and flush
the washer system. (Refer to 8 - ELECTRICAL/
REAR WIPERS/WASHERS - CLEANING).
(2) Inspect the washer plumbing for pinched, leak-
ing, deteriorated, or incorrectly routed hoses and
damaged or disconnected hose fittings. Replace dam-
aged or deteriorated hoses and hose fittings. Leaking
washer hoses can sometimes be repaired by cutting
the hose at the leak and splicing it back together
using an in-line connector fitting. Similarly, sections
of deteriorated hose can be cut out and replaced by
splicing in new sections of hose using in-line connec-
tor fittings. Whenever routing a washer hose or a
wire harness containing a washer hose, it must be
routed away from hot, sharp, or moving parts. Also,
sharp bends that might pinch the washer hose must
be avoided.
REAR CHECK VALVE
DESCRIPTION
A rear washer system check valve is standard
equipment on this model (Fig. 3). The rear check
valve is located in the washer plumbing between the
rear roof header and the roof outer panel near the
rear washer nozzle. The rear check valve consists of
a molded plastic body with a round center sectionand barbed hose nipples at each end. An arrow for-
mation molded into the center section of the valve
body indicates the direction of flow through the
valve. The rear check valve cannot be adjusted or
repaired and, if faulty or damaged, it must be
replaced.
OPERATION
The rear check valve prevents washer fluid from
draining out of the rear washer supply hoses back to
the washer reservoir. This drain-back would result in
a lengthy delay from when the rear washer switch is
actuated until washer fluid was dispensed through
the rear washer nozzle, because the washer pump
would have to refill the rear washer plumbing from
the reservoir to the nozzle. The check valve also pre-
vents washer fluid from siphoning through the rear
washer nozzle after the rear washer system is turned
Off.
Within the check valve body, a small check valve is
held in place against a seat by a small coiled spring
to restrict flow through the unit until the valve is
unseated by a predetermined inlet fluid pressure.
When the washer pump pressurizes and pumps
washer fluid from the reservoir through the rear
washer plumbing, the fluid pressure overrides the
spring pressure applied to the check ball within the
valve and unseats the valve, allowing washer fluid to
flow toward the rear washer nozzle. When the
washer pump stops operating, spring pressure seats
the check valve and fluid flow in either direction
within the rear washer plumbing is prevented.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the Center High Mounted Stop Lamp
(CHMSL) unit from the rear of the roof panel. (Refer
to 8 - ELECTRICAL/LAMPS/LIGHTING - EXTERI-
OR/CENTER HIGH MOUNTED STOP LAMP UNIT
- REMOVAL).
WARNING: THE EDGES OF THE SHEET METAL
AROUND THE CENTER HIGH MOUNTED STOP
LAMP MOUNTING HOLE IN THE ROOF PANEL.
TAKE THE PROPER PRECAUTIONS TO AVOID PER-
SONAL INJURY.
(3) Reach through the CHMSL unit mounting hole
in the rear of the roof panel to access and disconnect
the rear washer hose at the barbed nipple of the rear
washer nozzle (Fig. 4).
(4) Pull the rear washer hose through the CHMSL
unit mounting hole far enough to access and discon-
nect the headliner washer hose from the barbed nip-
ple of the rear check valve.
Fig. 3 Rear Check Valve
1 - INLET NIPPLE
2 - REAR CHECK VALVE
3 - OUTLET NIPPLE
4 - FLOW DIRECTION ARROW
8R - 34 REAR WIPERS/WASHERSKJ
REAR WIPERS/WASHERS (Continued)

(6) Position the camshaft drive gear into the tim-
ing chain aligning the V6 mark between the two
marked chain links (Two links marked during remov-
al).
(7) Using Special Tool 8428 Camshaft Wrench,
rotate the camshaft until the camshaft sprocket
dowel is aligned with the slot in the camshaft
sprocket. Install the sprocket onto the camshaft.
CAUTION: Remove excess oil from camshaft
sprocket bolt. Failure to do so can cause bolt over-
torque resulting in bolt failure.
(8) Remove excess oil from camshaft sprocket bolt,
then install the camshaft sprocket retaining bolt and
hand tighten.
(9) Remove timing chain wedge special tool 8379.
(10) Using Special Tool 6958 spanner wrench with
adapter pins 8346, torque the camshaft sprocket
retaining bolt to 122 N´m (90 ft. lbs.).
(11) Install the camshaft position sensor.
(12) Install the cylinder head cover.
CYLINDER HEAD COVER(S)
REMOVAL
(1) Disconnect battery negative cable.
(2) Remove air cleaner assembly, resonator assem-
bly and air inlet hose.
(3) Drain cooling system, below the level of the
heater hoses. Refer to COOLING SYSTEM.(4) Remove accessory drive belt.
(5) Remove air conditioning compressor retaining
bolts and move compressor to the left.
(6) Remove heater hoses.
(7) Disconnect injector and ignition coil connectors.
(8) Disconnect and remove positive crankcase ven-
tilation (PCV) hose.
(9) Remove oil fill tube.
(10) Un-clip injector and ignition coil harness and
move away from cylinder head cover.
(11) Remove right rear breather tube and filter
assembly.
(12) Remove cylinder head cover retaining bolts.
(13) Remove cylinder head cover.
INSTALLATION
CAUTION: Do not use harsh cleaners to clean the
cylinder head covers. Severe damage to covers
may occur.
NOTE: The gasket may be used again, provided no
cuts, tears, or deformation has occurred.
(1) Clean cylinder head cover and both sealing sur-
faces. Inspect and replace gasket as necessary.
(2) Tighten cylinder head cover bolts and double
ended studs to 12 N´m (105 in. lbs).
(3) Install right rear breather tube and filter
assembly.
(4) Connect injector, ignition coil electrical connec-
tors and harness retaining clips.
(5) Install the oil fill tube.
(6) Install PCV hose.
(7) Install heater hoses.
(8) Install air conditioning compressor retaining
bolts.
(9) Install accessory drive belt
(10) Fill Cooling system
(11) Install air cleaner assembly, resonator assem-
bly and air inlet hose.
(12) Connect battery negative cable.
INTAKE/EXHAUST VALVES &
SEATS
STANDARD PROCEDURE - REFACING
NOTE: Valve seats that are worn or burned can be
reworked, provided that correct angle and seat
width are maintained. Otherwise the cylinder head
must be replaced.
Fig. 23 Camshaft Bearing Caps Tightening
Sequence
9 - 34 ENGINE - 3.7LKJ
CAMSHAFT(S) (Continued)

ENGINE BLOCK
DESCRIPTION
The cylinder block is made of cast iron. The block
is a closed deck design with the left bank forward. To
provide high rigidity and improved NVH an
enhanced compacted graphite bedplate (Fig. 31) is
bolted to the block. The block design allows coolant
flow between the cylinders bores, and an internal
coolant bypass to a single poppet inlet thermostat is
included in the cast aluminum front cover.
STANDARD PROCEDURE - CYLINDER BORE
HONING
Before honing, stuff plenty of clean shop towels
under the bores and over the crankshaft to keep
abrasive materials from entering the crankshaft
area.
(1) Used carefully, the Cylinder Bore Sizing Hone
C-823, equipped with 220 grit stones, is the best tool
for this job. In addition to deglazing, it will reduce
taper and out-of-round, as well as removing light
scuffing, scoring and scratches. Usually, a few strokes
will clean up a bore and maintain the required lim-
its.
CAUTION: DO NOT use rigid type hones to remove
cylinder wall glaze.
(2) Deglazing of the cylinder walls may be done if
the cylinder bore is straight and round. Use a cylin-
der surfacing hone, Honing Tool C-3501, equipped
with 280 grit stones (C-3501-3810). about 20-60
strokes, depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Using honingoil C-3501-3880, or a light honing oil, available from
major oil distributors.
CAUTION: DO NOT use engine or transmission oil,
mineral spirits, or kerosene.
(3) Honing should be done by moving the hone up
and down fast enough to get a crosshatch pattern.
The hone marks should INTERSECT at 50É to 60É
for proper seating of rings (Fig. 32).
(4) A controlled hone motor speed between 200 and
300 RPM is necessary to obtain the proper cross-
hatch angle. The number of up and down strokes per
minute can be regulated to get the desired 50É to 60É
angle. Faster up and down strokes increase the cross-
hatch angle.
(5) After honing, it is necessary that the block be
cleaned to remove all traces of abrasive. Use a brush
to wash parts with a solution of hot water and deter-
gent. Dry parts thoroughly. Use a clean, white, lint-
free cloth to check that the bore is clean. Oil the
bores after cleaning to prevent rusting.
CLEANING
Thoroughly clean the oil pan and engine block gas-
ket surfaces.
Use compressed air to clean out:
²The galley at the oil filter adaptor hole.
²The front and rear oil galley holes.
²The feed holes for the crankshaft main bearings.
Fig. 31 CYLINDER BLOCK BEDPLATE
1 - Cylinder Block Bedplate
2 - Crankshaft Position Sensor
3 - Crankshaft Main Bearing Caps
Fig. 32 Cylinder Bore Crosshatch Pattern
1 - CROSSHATCH PATTERN
2 - INTERSECT ANGLE
KJENGINE - 3.7L 9 - 39

CRANKSHAFT OIL SEAL -
REAR
REMOVAL
NOTE: This procedure can be performed in vehicle.
(1) If being preformed in vehicle, remove the
transmission.
(2) Remove the flexplate (Refer to 9 - ENGINE/
ENGINE BLOCK/FLEX PLATE - REMOVAL).
NOTE: The crankshaft oil seal CAN NOT be reused
after removal.
NOTE: The crankshaft rear oil seal remover Special
Tool 8506 must be installed deeply into the seal.
Continue to tighten the removal tool into the seal
until the tool can not be turned farther. Failure to
install tool correctly the first time will cause tool to
pull free of seal without removing seal from engine.
(3) Using Special Tool 8506 (Fig. 48), remove the
crankshaft rear oil seal.
INSTALLATION
(1) Position the magnetic seal guide Special Tool
8349±2 (Fig. 49) onto the crankshaft rear face. Then
position the crankshaft rear oil seal onto the guide.(2) Using Special Tools 8349 Crankshaft Rear Oil
Seal Installer and C-4171 Driver Handle (Fig. 50),
with a hammer, tap the seal into place. Continue to
tap on the driver handle until the seal installer seats
against the cylinder block crankshaft bore.
(3) Install the flexplate.
(4) Install the transmission.
Fig. 48 Crankshaft Rear Oil Seal Removal
1 - REAR CRANKSHAFT SEAL
2 - SPECIAL TOOL 8506
Fig. 49 Crankshaft Rear Oil Seal Guide Special Tool
8349±2 and Oil
1 - REAR CRANKSHAFT SEAL
2 - SPECIAL TOOL 8349±2 GUIDE
Fig. 50 Crankshaft Rear Oil Seal Installation
1 - REAR CRANKSHAFT SEAL
2 - SPECIAL TOOL 8349±1 INSTALLER
3 - SPECIAL TOOL C-4171 HANDLE
9 - 48 ENGINE - 3.7LKJ

ENGINE - 2.4L
DESCRIPTION
The 2.4 Liter (148 cu. in.) in-line four cylinder
engine is a double over head camshaft with hydraulic
lifters and four valve per cylinder design. The engine
is free-wheeling; meaning it has provisions for piston-
to-valve clearance. However valve-to-valve interference
can occur, if camshafts are rotated independently.
The cylinders are numbered from front of the
engine to the rear. The firing order is 1±3±4±2.
The engine identification number is located on the
rear of the cylinder block (Fig. 1).
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE TEST
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.WARNING: DO NOT REMOVE THE PRESSURE CAP
WITH THE SYSTEM HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM COOLANT CAN
OCCUR.
Check the coolant level and fill as required. DO
NOT install the pressure cap.
Start and operate the engine until it attains nor-
mal operating temperature, then turn the engine
OFF.
Clean spark plug recesses with compressed air.
Remove the spark plugs.
Remove the oil filler cap.
Remove the air cleaner.
Calibrate the tester according to the manufactur-
er's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1,379
kPa (200 psi) maximum, with 552 kPa (80 psi) rec-
ommended.
Perform the test procedures on each cylinder
according to the tester manufacturer's instructions.
While testing, listen for pressurized air escaping
through the throttle body, tailpipe and oil filler cap
opening. Check for bubbles in the coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage per cylinder.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder.
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE TEST
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Check engine oil level and add oil if necessary.
(2) Drive the vehicle until engine reaches normal
operating temperature. Select a route free from traf-
fic and other forms of congestion, observe all traffic
laws, and accelerate through the gears several times
briskly.
(3) Remove all spark plugs from engine. As spark
plugs are being removed, check electrodes for abnor-
mal firing indicators fouled, hot, oily, etc. Record cyl-
inder number of spark plug for future reference.
(4) Remove the Auto Shutdown (ASD) relay from
the PDC.
(5) Be sure throttle blade is fully open during the
compression check.
(6) Insert compression gage adaptor Special Tool
8116 or the equivalent, into the #1 spark plug hole in
cylinder head. Connect the 0±500 psi (Blue) pressure
transducer with cable adaptors to the DRBIIIt.
Fig. 1 ENGINE IDENTIFICATION
1 - ENGINE IDENTIFICATION
KJENGINE9s-3