2002 JEEP LIBERTY Chain

NOTE: When the camshaft is removed the rocker
arms may slide downward, mark the rocker arms
before removing camshaft.
(9) Remove the camshaft bearing caps and the
camshaft.
INSTALLATION
(1) Lubricate camshaft journals with clean engine
oil.
NOTE: Position the left side camshaft so that the
camshaft sprocket dowel is near the 1 o'clock posi-
tion, This will place the camshaft at the neutral
position easing the installation of the camshaft
bearing caps.
(2) Position the camshaft into the cylinder head.
(3) Install the camshaft bearing caps, hand tighten
the retaining bolts.
NOTE: Caps should be installed so that the
stamped numbers on the caps are in numerical
order, ( 1 thru 4 ) from the front to the rear of the
engine. All caps should be installed so that the
stamped arrows on the caps point toward the front
of the engine.
(4) Working in ó turn increments, tighten the
bearing cap retaining bolts starting with the middle
cap working outward (Fig. 14).(5) Torque the camshaft bearing cap retaining
bolts to 11 N´m (100 in. lbs.).
(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 bolt, then install the
camshaft sprocket retaining bolt and hand tighten.
(9) Remove Special Tool 8379 timing chain wedge.
(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 cylinder head cover.
CYLINDER HEAD COVER(S)
DESCRIPTION
The cylinder head covers are made of single layer
stamped steel, and are not interchangable from side-
to-side (Fig. 15).
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the resonator assemble and air inlet
hose.
(3) Disconnect injector connectors and un-clip the
injector harness.
(4) Route injector harness in front of cylinder head
cover.
(5) Disconnect the left side breather tube and
remove the breather tube.
(6) Remove the cylinder head cover mounting bolts
(Fig. 16).
(7) Remove cylinder head cover and gasket.
NOTE: The gasket may be used again, providing no
cuts, tears, or deformation has occurred.
Fig. 14 Camshaft Bearing Caps Tightening
Sequence
KJENGINE - 3.7L 9 - 25
CAMSHAFT(S) (Continued)

(9) Using Special Tool 8516 Valve Spring Compres-
sor, install the rocker arms and the hydraulic lash
adjusters.
(10) Install the cylinder head cover. Refer to Cylin-
der Head Cover in this Section.
CYLINDER HEAD - RIGHT
DESCRIPTION
DESCRIPTION - CYLINDER HEAD
The cylinder heads are made of an aluminum alloy.
The cylinder head features two valves per cylinder
with pressed in powdered metal valve guides. The
cylinder heads also provide enclosures for the timing
chain drain, necessitating unique left and right cylin-
der heads.
DESCRIPTION - VALVE GUIDES
The valve guides are made of powered metal and
are pressed into the cylinder head. The guides are
not replaceable or serviceable, and valve guide ream-
ing is not recommended. If the guides are worn
beyond acceptable limits, replace the cylinder heads.
DESCRIPTION
The valves are made of heat resistant steel and
have chrome plated stems to prevent scuffing. Each
valve is actuated by a roller rocker arm which pivots
on a stationary lash adjuster. All valves use three
bead lock keepers to retain the springs and promote
valve rotation.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - HYDRAULIC LASH
ADJUSTER
A tappet-like noise may be produced from several
items. Check the following items.
(1) Engine oil level too high or too low. This may
cause aerated oil to enter the adjusters and cause
them to be spongy.
(2) Insufficient running time after rebuilding cylin-
der head. Low speed running up to 1 hour may be
required.
(3) Turn engine off and let set for a few minutes
before restarting. Repeat this several times after
engine has reached normal operating temperature.
(4) Low oil pressure.
(5) The oil restrictor in cylinder head gasket or the
oil passage to the cylinder head is plugged with
debris.(6) Air ingested into oil due to broken or cracked
oil pump pick up.
(7) Worn valve guides.
(8) Rocker arm ears contacting valve spring
retainer.
(9) Rocker arm loose, adjuster stuck or at maxi-
mum extension and still leaves lash in the system.
(10) Oil leak or excessive cam bore wear in cylin-
der head.
(11) Faulty lash adjuster.
²Check lash adjusters for sponginess while
installed in cylinder head and cam on camshaft at
base circle. Depress part of rocker arm over adjuster.
Normal adjusters should feel very firm. Spongy
adjusters can be bottomed out easily.
²Remove suspected lash adjusters, and replace.
²Before installation, make sure adjusters are at
least partially full of oil. This can be verified by little
or no plunger travel when lash adjuster is depressed.
DIAGNOSIS AND TESTING - CYLINDER HEAD
GASKET
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant
²Excessive steam (white smoke) emitting from
exhaust
²Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING). An
engine cylinder head gasket leaking between adja-
cent cylinders will result in approximately a 50±70%
reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
9 - 30 ENGINE - 3.7LKJ
VALVE SPRINGS (Continued)

VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL
(1) Disconnect battery negative cable.
(2) Raise the vehicle on a hoist.
(3) Disconnect the exhaust pipe at the right side
exhaust manifold.
(4) Drain the engine coolant. Refer to COOLING
SYSTEM.
(5) Lower the vehicle.
(6) Remove the intake manifold. Refer to proce-
dure.
(7) Remove the cylinder head cover. Refer to proce-
dure.
(8) Remove the fan shroud. Refer to COOLING
SYSTEM.
(9) Remove oil fill housing from cylinder head.
(10) Remove accessory drive belt. Refer to COOL-
ING SYSTEM.
(11) Rotate the crankshaft until the damper timing
mark is aligned with TDC indicator mark.
(12) Verify the V6 mark on the camshaft sprocket
is at the 12 o'clock position. Rotate the crankshaft
one turn if necessary.
(13) Remove the crankshaft damper. Refer to pro-
cedure.
(14) Remove the timing chain cover. Refer to pro-
cedure.
(15) Lock the secondary timing chains to the idler
sprocket using Special Tool 8429 Timing Chain Hold-
ing Fixture.NOTE: Mark the secondary timing chain prior to
removal to aid in installation.
(16) Mark the secondary timing chain, one link on
each side of the V6 mark on the camshaft drive gear.
(17) Remove the right side secondary chain ten-
sioner. Refer to Timing Chain and Sprockets in this
section.
(18) Remove the cylinder head access plug.
(19) Remove the right side secondary chain guide.
Refer to Timing Chain and Sprockets in this section.
CAUTION: The nut on the right side camshaft
sprocket should not be removed for any reason, as
the sprocket and camshaft sensor target wheel is
serviced as an assembly. If the nut was removed
retorque nut to 5 N´m (44 in. lbs.).
(20) Remove the retaining bolt and the camshaft
drive gear.
CAUTION: Do not allow the engine to rotate. severe
damage to the valve train can occur.
CAUTION: Do not overlook the four smaller bolts at
the front of the cylinder head. Do not attempt to
remove the cylinder head without removing these
four bolts.
CAUTION: Do not hold or pry on the camshaft tar-
get wheel for any reason. A damaged target wheel
can result in a vehicle no start condition.
NOTE: The cylinder head is attached to the cylinder
block with twelve bolts.
(21) Remove the cylinder head retaining bolts.
(22) Remove the cylinder head and gasket. Discard
the gasket.
CAUTION: Do not lay the cylinder head on its gas-
ket sealing surface, do to the design of the cylinder
head gasket any distortion to the cylinder head
sealing surface may prevent the gasket from prop-
erly sealing resulting in leaks.
CLEANING
To ensure engine gasket sealing, proper surface
preparation must be performed, especially with the
use of aluminum engine components (Fig. 22). (Refer
to 9 - ENGINE - STANDARD PROCEDURE)
KJENGINE - 3.7L 9 - 31
CYLINDER HEAD - RIGHT (Continued)

INSPECTION
(1) Inspect the cylinder head for out-of-flatness,
using a straightedge and a feeler gauge. If measure-
ments exceed 0.0508 mm (0.002 in.) replace the cyl-
inder head.
(2) Inspect the valve seats for damage. Service the
valve seats as necessary.
(3) Inspect the valve guides for wear, cracks or
looseness. If either condition exist, replace the cylin-
der head.
INSTALLATION
NOTE: The cylinder head bolts are tightened using
a torque plus angle procedure. The bolts must be
examined BEFORE reuse. If the threads are necked
down the bolts should be replaced.
Necking can be checked by holding a straight edge
against the threads. If all the threads do not contact
the scale, the bolt should be replaced.
CAUTION: When cleaning cylinder head and cylin-
der block surfaces, DO NOT use a metal scraper
because the surfaces could be cut or ground. Use
only a wooden or plastic scraper.
(1) Clean the cylinder head and cylinder block
mating surfaces.
(2) Position the new cylinder head gasket on the
locating dowels.CAUTION: When installing cylinder head, use care
not damage the tensioner arm or the guide arm.
(3) Position the cylinder head onto the cylinder
block. Make sure the cylinder head seats fully over
the locating dowels.
NOTE: The four M8 cylinder head mounting bolts
require sealant to be added to them before install-
ing. Failure to do so may cause leaks. Do not reuse
the old M8 bolts, use new M8 bolts.
(4) Lubricate the cylinder head bolt threads with
clean engine oil and install the eight M10 bolts.
(5) Coat the four M8 cylinder head bolts with
Mopar Lock and Seal Adhesivethen install the
bolts.
The cylinder head bolts are tightened using an
angle torque procedure, however, the bolts are not a
torque-to-yield design.
(6) Tighten the bolts in sequence using the follow-
ing steps and torque values:
²Step 1: Tighten bolts 1±10, 20 N´m (15 ft. lbs.).
²Step 2: Tighten bolts 1±10, 47 N´m (35 ft. lbs.).
Tighten bolts 11±14, 25 N´m (18 ft. lbs.).
²Step 3: Tighten bolts 1±10, 90 degrees. Tighten
bolts 11±14, 30 N´m (22 ft. lbs.).
CAUTION: The nut on the right side camshaft
sprocket should not be removed for any reason, as
the sprocket and camshaft sensor target wheel is
serviced as an assembly. If the nut was removed
retorque nut to 5 N´m (44 in. lbs.).
(7) Position the secondary chain onto the camshaft
drive gear, making sure one marked chain link is on
either side of the V6 mark on the gear then using
Special Tool 8428 Camshaft Wrench, position the
gear onto the camshaft.
CAUTION: Remove excess oil from camshaft
sprocket retaining bolt before reinstalling bolt. Fail-
ure to do so may cause over-torquing of bolt result-
ing in bolt failure.
(8) Install the camshaft drive gear retaining bolt.
(9) Install the right side secondary chain guide.
(10) Install the cylinder head access plug.
(11) Re-set and install the right side secondary
chain tensioner.
(12) Remove Special Tool 8429.
(13) Install the timing chain cover.
(14) Install the crankshaft damper.Tighten damper
bolt 175 N´m (130 Ft. Lbs.).
(15) Install accessory drive belt.
(16) Install the fan shroud.
(17) Install the cylinder head cover.
(18) Install the intake manifold.
Fig. 22 Proper Tool Usage For Surface Preparation
1 - PLASTIC/WOOD SCRAPER
9 - 32 ENGINE - 3.7LKJ
CYLINDER HEAD - RIGHT (Continued)

(19) Install oil fill housing onto cylinder head.
(20) Refill the cooling system.
(21) Raise the vehicle.
(22) Install the exhaust pipe onto the right
exhaust manifold.
(23) Lower the vehicle.
(24) Reconnect battery negitive cable.
(25) Start the engine and check for leaks.
CAMSHAFT(S)
DESCRIPTION
The camshafts consist of powdered metal steel
lobes which are sinter-bonded to a steel tube. Four
bearing journals are machined into the camshaft.
Camshaft end play is controlled by two thrust walls
that border the nose piece journal. Engine oil enters
the hollow camshafts at the third journal and lubri-
cates every intake lobe rocker through a drilled pas-
sage in the intake lobe.
REMOVAL
CAUTION: When the timing chain is removed and
the cylinder heads are still installed, DO NOT force-
fully rotate the camshafts or crankshaft indepen-
dently of each other. Severe valve and/or piston
damage can occur.
CAUTION: When removing the cam sprocket, timing
chains or camshaft, Failure to use special tool 8379
will result in hydraulic tensioner ratchet over exten-
sion, Requiring timing chain cover removal to re-set
the tensioner ratchet.
(1) Remove the cylinder head cover. Refer to CYL-
INDER HEAD COVER in this section.
(2) Set engine to TDC cylinder #1, camshaft
sprocket V6 marks at the 12 o'clock position.
(3) Mark one link on the secondary timing chain
on both sides of the V6 mark on the camshaft
sprocket to aid in installation.
CAUTION: Do not hold or pry on the camshaft tar-
get wheel for any reason, Severe damage will occur
to the target wheel. A damaged target wheel could
cause a vehicle no start condition.
(4) Loosen butDO NOTremove the camshaft
sprocket retaining bolt. Leave bolt snug against
sprocket.
NOTE: The timing chain tensioners must be
secured prior to removing the camshaft sprockets.
Failure to secure tensioners will allow the tension-ers to extend, requiring timing chain cover removal
in order to reset tensioners.
CAUTION: Do not force wedge past the narrowest
point between the chain strands. Damage to the
tensioners may occur.
(5) Position Special Tool 8379 timing chain wedge
between the timing chain strands. Tap the tool to
securely wedge the timing chain against the ten-
sioner arm and guide.
(6) Remove the camshaft position sensor.
(7) Hold the camshaft with Special Tool 8428 Cam-
shaft Wrench, while removing the camshaft sprocket
bolt and sprocket.
(8) Starting at the outside working inward, loosen
the camshaft bearing cap retaining bolts 1/2 turn at
a time. Repeat until all load is off the bearing caps.
CAUTION: DO NOT STAMP OR STRIKE THE CAM-
SHAFT BEARING CAPS. SEVERE DAMAGE WILL
OCCUR TO THE BEARING CAPS.
NOTE: When the camshaft is removed the rocker
arms may slide downward, mark the rocker arms
before removing camshaft.
(9) Remove the camshaft bearing caps and the
camshaft.
INSTALLATION
(1) Lubricate camshaft journals with clean engine
oil.
NOTE: Position the right side camshaft so that the
camshaft sprocket dowel is near the 10 o'clock
position, This will place the camshaft at the neutral
position easing the installation of the camshaft
bearing caps.
(2) Position the camshaft into the cylinder head.
(3) Install the camshaft bearing caps, hand tighten
the retaining bolts.
NOTE: Caps should be installed so that the
stamped numbers on the caps are in numerical
order, ( 1 thru 4 ) from the front to the rear of the
engine. All caps should be installed so that the
stamped arrows on the caps point toward the front
of the engine.
(4) Working in 1/2 turn increments, tighten the
bearing cap retaining bolts starting with the middle
cap working outward (Fig. 23).
(5) Torque the camshaft bearing cap retaining
bolts to 11 N´m (100 in. lbs.).
KJENGINE - 3.7L 9 - 33
CYLINDER HEAD - RIGHT (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)

Bearing
MarkSIZE USED WITH
JOURNAL SIZE
.025 US.025 mm 50.983-50.967 mm
(.001 in.) (2.0073-2.0066 in.)
Std.STANDARD 50.992-51.008 mm
(2.0076-2.0082 in.)
.250 US.250 mm 50.758-50.742 mm
(.010 in.) (1.9984-1.9978 in.)
(9) Repeat the Plastigage measurement to verify
your bearing selection prior to final assembly.
(10) Once you have selected the proper insert,
install the insert and cap. Tighten the connecting rod
bolts to 27 N´m (20 ft. lbs.) plus a 90É turn.
Slide snug-fitting feeler gauge between the con-
necting rod and crankshaft journal flange (Fig. 39).
Refer to Engine Specifications for the proper clear-
ance. Replace the connecting rod if the side clearance
is not within specification.
CRANKSHAFT
DESCRIPTION
The crankshaft (Fig. 40) is constructed of nodular
cast iron. The crankshaft is a three throw split pin
design with six counterweights for balancing pur-
poses. The crankshaft is supported by four select fit
main bearings with the number two serving as the
thrust washer location. The main journals of the
crankshaft are cross drilled to improve rod bearinglubrication. The number six counterweight has provi-
sions for crankshaft position sensor target wheel
mounting. The select fit main bearing markings are
located on the rear side of the target wheel. The
crankshaft oil seals are one piece design. The front
oil seal is retained in the timing chain cover, and the
rear seal is pressed in to a bore formed by the cylin-
der block and the bedplate assembly.
Fig. 38 Measuring Bearing Clearance with
Plastigage
1 - PLASTIGAGE SCALE
2 - COMPRESSED PLASTIGAGE
Fig. 39 Checking Connecting Rod Side Clearance -
Typical
Fig. 40 CRANKSHAFT AND TARGET RING
1 - CRANKSHAFT
2 - CRANKSHAFT POSITION SENSOR TARGET RING
9 - 42 ENGINE - 3.7LKJ
CONNECTING ROD BEARINGS (Continued)

(10) Remove damper using Special Tools 8513
Insert and 1026 Three Jaw Puller (Fig. 45).
(11) Using Special Tool 8511, remove crankshaft
front seal (Fig. 46).INSTALLATION
CAUTION: To prevent severe damage to the Crank-
shaft, Damper or Special Tool 8512, thoroughly
clean the damper bore and the crankshaft nose
before installing Damper.
(1) Using Special Tool 8348 and 8512, install
crankshaft front seal (Fig. 47).
(2) Install vibration damper (Refer to 9 - ENGINE/
ENGINE BLOCK/VIBRATION DAMPER - INSTAL-
LATION).
(3) Install radiator cooling fan and shroud (Refer
to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION).
(4) Install upper radiator hose.
(5) Install A/C compressor and tighten fasteners to
54 N´m (40 ft. lbs.).
(6) Install accessory drive belt refer (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(7) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(8) Connect negative cable to battery.
Fig. 45 Crankshaft DamperÐRemoval
1 - SPECIAL TOOL 8513 INSERT
2 - SPECIAL TOOL 1026
Fig. 46 Crankshaft Front SealÐRemoval
1 - SPECIAL TOOL 8511
Fig. 47 Crankshaft Front SealÐInstallation
1 - TIMING CHAIN COVER
2 - SPECIAL TOOL 8348
3 - SPECIAL TOOL 8512
KJENGINE - 3.7L 9 - 47
CRANKSHAFT OIL SEAL - FRONT (Continued)