3.7 v6 JEEP LIBERTY 2002 KJ / 1.G Workshop Manual

(20) After installing all chains, it is recommended
that the idler gear end play be checked (Fig. 112).
The end play must be within 0.10±0.25 mm (0.004±
0.010 in.). If not within specification, the idler gear
must be replaced.
(21) Install timing chain cover and crankshaft
damper. Refer to procedures.
(22) Install cylinder head covers. Refer to proce-
dures.
NOTE: Before installing threaded plug in right cylin-
der head, the plug must be coated with sealant to
prevent leaks.(23) Coat the large threaded access plug with
MopartThread Sealant with Teflon, then install
into the right cylinder head and tighten to 81 N´m
(60 ft. lbs.).
(24) Install the oil fill housing.
(25) Install access plug in left cylinder head.
(26) Install power steering pump.
(27) Fill cooling system.
(28) Connect negative cable to battery.
Fig. 111 Tightening Right Side Camshaft Sprocket
Bolt
1 - TORQUE WRENCH
2 - SPECIAL TOOL 6958 WITH ADAPTER PINS 8346
3 - LEFT CAMSHAFT SPROCKET
4 - RIGHT CAMSHAFT SPROCKETFig. 112 Measuring Idler Gear End Play
1 - IDLER SPROCKET ASSEMBLY
2 - DIAL INDICATOR
9 - 82 ENGINE - 3.7LKJ
TIMING BELT/CHAIN AND SPROCKET(S (Continued)

DESCRIPTION SPECIFICATION
Exhaust 6.60 mm
(0.259 t>
Intake Valve Timing*
Closes (ABDC) 51É
Opens (BTDC) 1É
Duration 232É
Exhaust Valve Timing*
Closes (ATDC) 7É
Opens (BBDC) 47É
Duration 234É
Valve Overlap 8É
*All readings in crankshaft degrees. Timing points @
4É from top of Ramps.
Cylinder Head
Material Cast Aluminum
Gasket Thickness
(Compressed)0.71 mm
(0.028 in.)
Valve Seat
Angle 44.5±45É
Seat DiameterÐIntake 34.37±34.63 mm
(1.353±1.363 in.)
Seat DiameterÐExhaust 27.06±27.32 mm
(1.065±1.075 in.)
Runout (Max.) 0.05 mm
(0.002 in.)
Valve Seat WidthÐIntake
and Exhaust0.9±1.3 mm
(0.035±0.051 in.)
Service LimitÐIntake 2.0 mm
(0.079 in.)
Service LimitÐExhaust 2.5 mm
(0.098 in.)
Valve Guide
Diameter I.D. 5.975±6.000 mm
(0.235±0.236 in.)
Guide Bore Diameter 11.0±11.02 mm
(0.4330±0.4338 in.)
Guide Height (spring seat
to guide tip)13.25±13.75 mm
(0.521±0.541 in.)
Valves
Face AngleÐIntake and
Exhaust44.5Ð45ÉDESCRIPTION SPECIFICATION
Head DiameterÐIntake 34.67±34.93 mm
1.364±1.375 in.)
Head DiameterÐExhaust 28.32±28.52 mm
(1.114±1.122 in.)
Valve Length (Overall)
ÐIntake 112.76±113.32 mm
(4.439±4.461 in.)
ÐExhaust 110.89±111.69 mm
(4.365±4.397 in.)
Valve Stem Diameter
ÐIntake 5.934±5.952 mm
(0.2337±0.2344 in.)
ÐExhaust 5.906±5.924 mm
(0.2326±0.2333 in.)
Valve Margin
Intake 1.2±1.7 mm
(0.047±0.066 in.)
Service Limit 0.95 mm
(1/32 in.)
Exhaust 0.985±1.315 mm
(0.038±0.051 in.)
Service Limit 1.05 mm
(3/64 in.)
Valve Stem Tip
Intake 48.04 mm
(1.891 in.)
Exhaust 47.99 mm
(1.889 in.)
Valve Stem to Guide Clearance
Intake 0.048±0.066 mm
(0.0018±0.0025 in.)
Max. Allowable 0.076 mm
(0.003 in.)
Service Limit 0.25 mm
(0.010 in.)
Exhaust 0.0736±0.094 mm
(0.0029±0.0037 in.)
Max. Allowable 0.101 mm
(0.004 in.)
Service Limit 0.25 mm
(0.010 in.)
KJENGINE9s-15
ENGINE - 2.4L (Continued)

Remove all gasket material from cylinder head and
block (Refer to 9 - ENGINE - STANDARD PROCE-
DURE). Be careful not to gouge or scratch the alumi-
num head sealing surface.
Clean all engine oil passages.
INSPECTION
(1) Cylinder head must be flat within 0.1 mm
(0.004 in.) (Fig. 6).
(2) Inspect camshaft bearing journals for scoring.
(3) Remove carbon and varnish deposits from
inside of valve guides with a reliable guide cleaner.
(4) Using a small hole gauge and a micrometer,
measure valve guides in 3 places top, middle and bot-
tom (Fig. 7). (Refer to 9 - ENGINE - SPECIFICA-
TIONS) Replace guides if they are not within
specification.
(5) Check valve guide height (Fig. 8).
INSTALLATION - CYLINDER HEAD
NOTE: The Cylinder head bolts should be examined
BEFORE reuse. If the threads are necked down, the
bolts must be replaced (Fig. 9).
Necking can be checked by holding a scale or
straight edge against the threads. If all the threads
do not contact the scale, the bolt should be replaced.
(1) Before installing the bolts, the threads should
be coated with engine oil.
(2) Position cylinder head gasket on engine block
(Fig. 10).
(3) Install cylinder head on engine block.
(4) Tighten the cylinder head bolts in the sequence
shown in (Fig. 11). Using the 4 step torque turn
method, tighten according to the following values:
²First All to 34 N´m (25 ft. lbs.)
²Second All to 68 N´m (50 ft. lbs.)
Fig. 6 Checking Cylinder Head Flatness
1 - FEELER GAUGE
2 - STRAIGHT EDGE
Fig. 7 Checking Wear on Valve GuideÐTypical
1-TOP
2 - MIDDLE
3 - BOTTOM
4 - CUT AWAY VIEW OF VALVE GUIDE MEASUREMENT
LOCATIONS
Fig. 8 Valve Guide Height
1 - VALVE GUIDE
2 - 13.25 - 13.75 MM (.521 - .541 IN.)
3 - SPRING SEAT
Fig. 9 Checking Bolts for Stretching (Necking)
1 - STRETCHED BOLT
2 - THREADS ARE NOT STRAIGHT ON LINE
3 - THREADS ARE STRAIGHT ON LINE
4 - UNSTRETCHED BOLT
KJENGINE9s-21
CYLINDER HEAD (Continued)

REAR MOUNT
REMOVAL
NOTE: A resilient rubber cushion supports the
transmission at the rear between the transmission
extension housing and the rear support crossmem-
ber or skid plate.
(1) Disconnect negative cable from battery.
(2) Raise the vehicle and support the transmission.
(3) Remove the nuts holding the support cushion
to the crossmember. Remove the crossmember.
MANUAL TRANSMISSION
a. Remove the support cushion nuts and remove
the cushion.
b. Remove the transmission support bracket bolts
and remove the bracket from the transmission.
AUTOMATIC TRANSMISSION
c. Remove the support cushion bolts and remove
the cushion and the support bracket from the trans-
mission (4WD) or from the adaptor bracket (2WD).
d. On 2WD vehicles, remove the bolts holding the
transmission support adaptor bracket to the trans-
mission. Remove the adaptor bracket.
INSTALLATION
MANUAL TRANSMISSION:
(1) Install the support cushion to the transmission
(Fig. 74)or (Fig. 75). Install the bolts and tighten.
(2) Position the crossmember in the vehicle. Install
the crossmember to mount through bolt and nut.
(3) Install crossmember-to-sill bolts and tighten to
41 N´m (30 ft. lbs.) torque.
(4) Remove the transmission support.
(5) Lower the vehicle.
(6) Connect negative cable to battery.
AUTOMATIC TRANSMISSION:
(1) Install the transmission mount to transmission
(Fig. 76) and (Fig. 77). Install the bolts.
(2) Position the crossmember in the vehicle. Install
the crossmember to mount through bolt and nut.
(3) Remove the transmission support.
(4) Lower the vehicle.
(5) Connect negative cable to battery.
Fig. 74 TRANSMISSION MOUNT-2.4L MANUAL
TRANS
1 - TRANSMISSION MOUNT
2 - MOUNTING BOLT
Fig. 75 TRANSMISSION MOUNT 3.7L MANUAL
TRANS 2WD
1 - NUT
2 - BOLT
3 - TRANS MOUNT
KJENGINE9s-45

LUBRICATION
DESCRIPTION
The lubrication system is a full-flow filtration,
pressure feed type. The oil pump is mounted in the
front engine cover and driven by the crankshaft.
OPERATION
Engine oil drawn up through the pickup tube and
is pressurized by the oil pump and routed through
the full-flow filter to the main oil gallery running the
length of the cylinder block. A diagonal hole in each
bulkhead feeds oil to each main bearing. Drilled pas-
sages within the crankshaft route oil from main bear-
ing journals to connecting rod journals. Balance shaft
lubrication is provided through an oil passage from
the number one main bearing cap through the bal-
ance shaft carrier support leg. This passage directly
supplies oil to the front bearings and internal
machined passages in the shafts that routes oil from
front to the rear shaft bearing journals. A vertical
hole at the number five bulkhead routes pressurized
oil through a restrictor (integral to the cylinder head
gasket) up past a cylinder head bolt to an oil gallery
running the length of the cylinder head. The cam-
shaft journals are partially slotted to allow a prede-
termined amount of pressurized oil to pass into the
bearing cap cavities. Lubrication of the camshaft
lobes are provided by small holes in the camshaft
bearing caps that are directed towards each lobe. Oil
returning to the pan from pressurized components
supplies lubrication to the valve stems. Cylinder
bores and wrist pins are splash lubricated from
directed slots on the connecting rod thrust collars.
DIAGNOSIS AND TESTING - ENGINE OIL
PRESSURE CHECKING
(1) Disconnect and remove oil pressure switch.
(Refer to 9 - ENGINE/LUBRICATION/OIL PRES-
SURE SENSOR/SWITCH - REMOVAL)
(2) Install Special Tools C-3292 Gauge with 8406
Adaptor fitting.
(3) Start engine and record oil pressure. Refer to
Specifications for correct oil pressure requirements.
(Refer to 9 - ENGINE - SPECIFICATIONS)
CAUTION: If oil pressure is 0 at idle, do not perform
the 3000 RPM test
(4) If oil pressure is 0 at idle. Shut off engine,
check for pressure relief valve stuck open, a clogged
oil pick-up screen or a damaged oil pick-up tube
O-ring.
(5) After test is complete, remove test gauge and
fitting.
Fig. 76 TRANSMISSION MOUNT 3.7L 2WD AUTO
TRANS
1 - BOLT
2 - MOUNT
Fig. 77 TRANSMISSION MOUNT 3.7L 4WD AUTO
TRANS
1 - MOUNT
2 - BOLT
9s - 46 ENGINEKJ
LUBRICATION (Continued)

WARNING: THE NORMAL OPERATING TEMPERA-
TURE OF THE EXHAUST SYSTEM IS VERY HIGH.
THEREFORE, NEVER WORK AROUND OR ATTEMPT
TO SERVICE ANY PART OF THE EXHAUST SYSTEM
UNTIL IT IS COOLED. SPECIAL CARE SHOULD BE
TAKEN WHEN WORKING NEAR THE CATALYTIC
CONVERTER. THE TEMPERATURE OF THE CON-
VERTER RISES TO A HIGH LEVEL AFTER A SHORT
PERIOD OF ENGINE OPERATION TIME.
(1) Install the crossove pipe into the hanger insu-
lator.
(2) Install and torque the fasteners in the cross-
over pipe to the left and right catalytic converter con-
nection.
(3) Install and torque the retaining fasteners hold-
ing the crossover pipe to exhaust pipe.
(4) Lower vehicle..
(5) Start engine and check for leaks.
HEAT SHIELDS
DESCRIPTION
Heat shields are needed to protect both the vehicle
and the environment from the high temperatures
developed by the catalytic converter. The catalytic
converter releases additional heat into the exhaustsystem. Under severe operating conditions, the tem-
perature increases in the area of the converter. Such
conditions can exist when the engine misfires or oth-
erwise does not operate at peak efficiency (Fig. 3).
MUFFLER
DESCRIPTION
The 3.7L engine uses a galvanized steel muffler
(Fig. 4) to control exhaust noise levels and exhaust
back pressure.
Fig. 2 Crossover Pipe
1 - Crossover-toCatalytic Converter flange
2 - Crossover Pipe
3 - Crossover Pipe to Tail Pipe Flange
4 - Hanger Bracket
Fig. 3 Front and Rear Floor Pan Heat Shields
Typical
1 - REAR FLOOR PAN HEAT SHIELD
2 - HEAT SHIELD RETAINING NUTS
3 - FRONT FLOOR PAN HEAT SHIELD
Fig. 4 Muffler - Typical
1 - MUFFLER
11 - 4 EXHAUST SYSTEMKJ
CROSS-OVER PIPE (Continued)

2.4L ENGINES
(1) Disconnect the oxygen sensors.
(2) Remove the two bolts and flanged nuts at the
manifold (Fig. 1).
(3) Lower the catalyst assembly and slide out of
the mount at the transmission (if equipped).
(4) Remove the catalyst assembly from the vehicle.
3.7L ENGINES
NOTE: Do not remove nut from T-Bolt. Only remove
nut far enough, so that the T end can be removed
from the clamp.
(1) Remove the T bolt end of the fastener, from the
clamp.
(2) Spread the clamp, and remove the catalytic
converter from the vehicle.
(3) Discard the clamp (Fig. 2).
NOTE: The catalytic converter to exhaust manifold
clamp is not reusable. Always use a new clamp
when reinstalling the catalytic converter.
INSPECTION
Look at the stainless steel body of the converter,
inspect for bulging or other distortion that could be a
result of overheating. If the converter has a heat
shield attached make sure it is not bent or loose.
If you suspect internal damage to the catalyst, tap-
ping the bottom of the catalyst with a rubber mallet
may indicate a damaged core.
INSTALLATION
(1) Position the catalytic converter onto the
exhaust pipe flange connection. Tighten the nuts to
28 N´m (250 in. lbs.) torque.
(2) Install the muffler onto the catalytic converter
until the alignment tab is inserted into the align-
ment slot.
(3) Install the exhaust clamp at the muffler and
catalytic converter connection. Tighten the clamp
nuts to 47 N´m (35 ft. lbs.) torque.
(4) Connect oxygen sensor wiring.
(5) Lower the vehicle.
(6) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels.
Adjust the alignment, if needed.
Fig. 1 2.4L CATALYST ASSEMBLY - 4x4
1- FLANGED NUT
2- CATALYST ASSEMBLY
3- BOLT
4- HANGER
5- NUT
Fig. 2 Catalyst Removal
1 - V-Clamp
2 - Catalytic Converter
3 - Flange
4 - Crossover Pipe
5 - T-Bolt
KJEXHAUST SYSTEM 11s - 3
CATALYTIC CONVERTER (Continued)

CROSS-OVER PIPE
REMOVAL
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINES.
WARNING: THE NORMAL OPERATING TEMPERA-
TURE OF THE EXHAUST SYSTEM IS VERY HIGH.
THEREFORE, NEVER WORK AROUND OR ATTEMPT
TO SERVICE ANY PART OF THE EXHAUST SYSTEM
UNTIL IT IS COOLED. SPECIAL CARE SHOULD BE
TAKEN WHEN WORKING NEAR THE CATALYTIC
CONVERTER. THE TEMPERATURE OF THE CON-
VERTER RISES TO A HIGH LEVEL AFTER A SHORT
PERIOD OF ENGINE OPERATION TIME.
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with lubricant.
Allow 5 minutes for penetration.
(3) Remove the retaining fasteners holding cross-
over pipe to exhaust pipe.
(4) Remove the fasteners from the crossover pipe
to the catalytic converter connection.
(5) Remove the crossove pipe from the hanger
insulator (Fig. 3).
INSTALLATION
WARNING: IF TORCHES ARE USED WHEN WORK-
ING ON THE EXHAUST SYSTEM, DO NOT ALLOW
THE FLAME NEAR THE FUEL LINES.
WARNING: THE NORMAL OPERATING TEMPERA-
TURE OF THE EXHAUST SYSTEM IS VERY HIGH.
THEREFORE, NEVER WORK AROUND OR ATTEMPT
TO SERVICE ANY PART OF THE EXHAUST SYSTEM
UNTIL IT IS COOLED. SPECIAL CARE SHOULD BE
TAKEN WHEN WORKING NEAR THE CATALYTIC
CONVERTER. THE TEMPERATURE OF THE CON-
VERTER RISES TO A HIGH LEVEL AFTER A SHORT
PERIOD OF ENGINE OPERATION TIME.
(1) Install the crossove pipe into the hanger insu-
lator.
(2) Install and torque the fasteners in the cross-
over pipe to the left and right catalytic converter con-
nection.
(3) Install and torque the retaining fasteners hold-
ing the crossover pipe to exhaust pipe.
(4) Lower vehicle..
(5) Start engine and check for leaks.
HEAT SHIELDS
DESCRIPTION
Heat shields (Fig. 4) are needed to protect both the
vehicle and the environment from the high tempera-
tures developed by the catalytic converter. The cata-
lytic converter releases additional heat into the
exhaust system. Under severe operating conditions,
the temperature increases in the area of the con-
verter. Such conditions can exist when the engine
misfires or otherwise does not operate at peak effi-
ciency.
MUFFLER
DESCRIPTION
The 2.4L and 3.7L engine uses a galvanized steel
muffler (Fig. 5) to control exhaust noise levels and
exhaust back pressure.
REMOVAL
All original equipment exhaust systems are manu-
factured with the exhaust tailpipe welded to the muf-
fler. Service replacement mufflers and exhaust
tailpipes are either clamped together or welded
together.Fig. 3 Crossover Pipe
1 - Crossover-toCatalytic Converter flange
2 - Crossover Pipe
3 - Crossover Pipe to Tail Pipe Flange
4 - Hanger Bracket
11s - 4 EXHAUST SYSTEMKJ

SPECIFICATIONS
FUEL SYSTEM PRESSURE
339 kPa +/- 34 kPa (49.2 psi +/- 2 psi).
TORQUE
DESCRIPTION N-m Ft. Lbs. In. Lbs.
Accelerator Pedal Bracket Mounting Nuts 12 - 105
Crankshaft Position Sensor - 2.4L 28 21 -
Crankshaft Position Sensor - 3.7L 28 21 -
Camshaft Position Sensor - 2.4L 12 - 106
Camshaft Position Sensor - 3.7L 12 - 106
Engine Coolant Temperature Sensor 11 - 96
EVAP Canister-to-Body Bolts 48 35 -
EVAP Canister-to-Canis. Bracket Bolt/Nut 11 - 100
Fuel Filler Hose Clamp at Tank 3 - 30
Fuel Filler Housing-to-Body Screws 2 - 17
Fuel Filter Mounting Nut at Tank 5.5 - 49
Fuel Pump Module Access Plate Nuts 3 - 26
Fuel Rail Mounting Bolts - 3.7L 11 - 100
Fuel Rail Mounting Bolts - 2.4L 28 - 250
Fuel Tank Heat Sheild Nuts 5.5 - 49
Fuel Tank Mounting Strap Bolts 61 45 -
Fuel Tank Skid Plate and Trailer Hitch 88 65 -
IAC Motor Mounting Screws 7 - 60
Leak Detection Pump Mounting Bracket-to-Fuel
Tank Nuts5.5 - 49
Leak Detection Pump-to-Bracket Nuts 1.2 - 11
Map Sensor Mounting Screws 3 - 25
PCM-to-Mounting Bracket Mounting Screws 4 - 35
Power Steering Pressure Switch 14-22 - 124-195
TPS Mounting Screws 7 - 60
Throttle Body Mounting Bolts 11 - 100
Oxygen Sensors 30 22 -
KJFUEL DELIVERY 14 - 5
FUEL DELIVERY (Continued)

FUEL RAIL
DESCRIPTION
2.4L
The fuel injector rail is used to mount the fuel
injectors to the engine (Fig. 31). On the 2.4L 4-cylin-
der engine, afuel damperis located near the front
of the fuel rail (Fig. 31).
3.7L
The fuel injector rail is mounted to the intake
manifold (Fig. 32). It is used to mount the fuel injec-
tors to the engine. The rail is equipped with a test
port (Fig. 33) to check/test fuel system pressure.
A fuel rail mounted, fuel damper is not used with
this engine.
OPERATION
2.4L
The fuel injector rail supplies the necessary fuel to
each individual fuel injector.The fuel damper is used only to help control fuel
pressure pulsations. These pulsations are the result
Fig. 31 FUEL RAIL-2.4L
1 - FUEL RAIL
2 - MOUNTING BOLTS
3 - TEST PORT
4 - QUICK-CONNECT FITTING
5 - INJ. #1
6 - DAMPER
7 - INJ #2
8 - INJ #3
9 - INJ #4
10- INJECTOR RETAINING CLIP
Fig. 32 FUEL RAIL - 3.7L
1 - MOUNTING BOLTS (4)
2 - QUICK-CONNECT FITTING
3 - FUEL RAIL
4 - INJ. #1
5 - INJ. #3
6 - INJ. #5
7 - INJ. #2
8 - INJ. #4
9 - INJ. #6
10 - CONNECTOR TUBE
Fig. 33 FUEL RAIL TEST PORT - 3.7L
1 - FUEL RAIL
2 - TEST PORT
KJFUEL DELIVERY 14 - 21