2002 JEEP LIBERTY 3.7 v6

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)

NOTE: When refacing valves and valve seats, it is
important that the correct size valve guide pilot be
used for reseating stones. A true and complete sur-
face must be obtained.
(1) Using a suitable dial indicator measure the
center of the valve seat Total run out must not
exceed 0.051 mm (0.002 in).
(2) Apply a small amount of Prussian blue to the
valve seat, insert the valve into the cylinder head,
while applying light pressure on the valve rotate the
valve. Remove the valve and examine the valve face.
If the blue is transferred below the top edge of the
valve face, lower the valve seat using a 15 degree
stone. If the blue is transferred to the bottom edge of
the valve face, raise the valve seat using a 65 degree
stone.
(3) When the seat is properly positioned the width
of the intake seat must be 1.75 ± 2.36 mm (0.0689 ±
0.0928 in.) and the exhaust seat must be 1.71 ± 2.32
mm (0.0673 ± 0.0911 in.).
(4) Check the valve spring installed height after
refacing the valve and seat. The installed height for
both intake and exhaust valve springs must not
exceed 41.44 mm (1.6315 in.).
(5) The valve seat and valve face must maintain a
face angle of 44.5 ± 45 degrees angle (Fig. 24).REMOVAL
NOTE: The cylinder heads must be removed in
order to perform this procedure.
(1) Remove rocker arms and lash adjusters. Refer
to procedures in this section (Fig. 25).
(2) Remove the camshaft bearing caps and the
camshaft.
NOTE: All six valve springs and valves are removed
in the same manner; this procedure only covers
one valve and valve spring.
(3) Using Special Tool C-3422±B or C-3422±C
Valve Spring Compressor and Special tool 8519
Adapter, compress the valve spring.
NOTE: It may be necessary to tap the top of the
valve spring to loosen the spring retainers locks
enough to be removed.
(4) Remove the two spring retainer lock halves.
NOTE: the valve spring is under tension use care
when releasing the valve spring compressor.
(5) Remove the valve spring compressor.
(6) Remove the spring retainer, and the spring.
Fig. 24 Valve Assembly Configuration
1 - VALVE LOCKS (3±BEAD)
2 - RETAINER
3 - VALVE STEM OIL SEAL
4 - INTAKE VALVE
5 - EXHAUST VALVE
6 - VALVE SPRING
Fig. 25 Rocker Arm Removal
1 - CAMSHAFT
2 - SPECIAL TOOL 8516
KJENGINE - 3.7L 9 - 35
INTAKE/EXHAUST VALVES & SEATS (Continued)

NOTE: Check for sharp edges on the keeper
grooves. Remove any burrs from the valve stem
before removing the valve from the cylinder head.
(7) Remove the valve from the cylinder head.
NOTE: The valve stem seals are common between
intake and exhaust.
(8) Remove the valve stem seal. Mark the valve for
proper installation.
TESTING VALVE SPRINGS
NOTE: Whenever the valves are removed from the
cylinder head it is recommended that the valve
springs be inspected and tested for reuse.
Inspect the valve springs for physical signs of wear
or damage. Turn table of tool C-647 until surface is
in line with the 40.69 mm (1.602 in.) mark on the
threaded stud and the zero mark on the front. Place
spring over the stud on the table and lift compress-
ing lever to set tone device. Pull on torque wrench
until Ping is heard. Take reading on torque wrench
at this instant. Multiply this reading by two. This
will give the spring load at test length. Fractional
measurements are indicated on the table for finer
adjustments. Refer to Specifications Section to obtain
specified height and allowable tensions. Replace any
springs that do not meet specifications (Fig. 26).
INSTALLATION
(1) coat the valve stem with clean engine oil and
insert it into the cylinder head.
(2) Install the valve stem seal. make sure the seal
is fully seated and that the garter spring at the top
of the seal is intact.
(3) Install the spring and the spring retainer.
(4) Using the valve spring compressor, compress
the spring and install the two valve spring retainer
halves (Fig. 27).
(5) Release the valve spring compressor and make
sure the two spring retainer halves and the spring
retainer are fully seated.
(6) lubricate the camshaft journal with clean
engine oil then Position the camshaft (with the
sprocket dowel on the left camshaft at 11 o'clock and
the right camshaft at 12 o'clock), then position the
camshaft bearing caps.
(7) Install the camshaft bearing cap retaining
bolts. Tighten the bolts 9±13 N´m (100 in. lbs.) in ó
turn increments in the sequence shown (Fig. 28).
(8) Position the hydraulic lash adjusters and
rocker arms.
Fig. 26 Testing Valve Springs
1 - SPECIAL TOOL C-647
Fig. 27 Valve Assembly Configuration
1 - VALVE LOCKS (3±BEAD)
2 - RETAINER
3 - VALVE STEM OIL SEAL
4 - INTAKE VALVE
5 - EXHAUST VALVE
6 - VALVE SPRING
9 - 36 ENGINE - 3.7LKJ
INTAKE/EXHAUST VALVES & SEATS (Continued)

ROCKER ARM
DESCRIPTION
The rocker arms are steel stampings with an inte-
gral roller bearing. The rocker arms incorporate a 2.8
mm (0.11 inch) oil hole in the lash adjuster socket for
roller and camshaft lubrication.
REMOVAL
NOTE: Disconnect the battery negative cable to pre-
vent accidental starter engagement.
(1) Remove the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) For rocker arm removal on cylinder #4, Rotate
the crankshaft until cylinder #1 is at TDC exhaust
stroke.
(3) For rocker arm removal on cylinder #1, Rotate
the crankshaft until cylinder #1 is at TDC compres-
sion stroke.
(4) For rocker arm removal on cylinders #2 and #3,
Rotate the crankshaft until cylinder #1 is at BDC
compression stroke.
(5) For rocker arm removal on cylinders #5 and #6,
Rotate the crankshaft until cylinder #1 is at BDC
exhaust stroke.
(6) Using special tool 8516 Rocker Arm Remover,
press downward on the valve spring, remove rocker
arm (Fig. 29).
INSTALLATION
CAUTION: Make sure the rocker arms are installed
with the concave pocket over the lash adjusters.
Failure to do so may cause severe damage to the
rocker arms and/or lash adjusters.
NOTE: Coat the rocker arms with clean engine oil
prior to installation.
(1) For rocker arm installation on cylinders #4,
Rotate the crankshaft until cylinder #1 is at TDC
exhaust stroke.
(2) For rocker arm installation on cylinder #1,
Rotate the crankshaft until cylinder #1 is at TDC
compression stroke.
(3) For rocker arm installation on cylinders #2 and
#3, Rotate the crankshaft until cylinder #1 is at BDC
compression stroke.
(4) For rocker arm installation on cylinders #5 and
#6, Rotate the crankshaft until cylinder #1 is at BDC
exhaust stroke.
(5) Using special tool 8516 press downward on the
valve spring, install rocker arm (Fig. 30).
(6) Install the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
Fig. 28 Camshaft Bearing Caps Tightening
SequenceFig. 29 Rocker Arm - Removal
1 - CAMSHAFT
2 - SPECIAL TOOL 8516
KJENGINE - 3.7L 9 - 37
INTAKE/EXHAUST VALVES & SEATS (Continued)

VALVE GUIDE SEALS
DESCRIPTION
The valve guide seals are made of rubber and
incorporate an integral steel valve spring seat. The
integral garter spring maintains consistent lubrica-
tion control to the valve stems.
VALVE SPRINGS
DESCRIPTION
The valve springs are made from high strength
chrome silicon steel. The springs are common for
intake and exhaust applications. The valve spring
seat is integral with the valve stem seal, which is a
positive type seal to control lubrication.
REMOVAL
(1) Remove the cylinder head cover. Refer to Cyl-
inder Head Cover in this Section.
(2) Using Special Tool 8516 Valve Spring Compres-
sor, remove the rocker arms and the hydraulic lash
adjusters.
(3) Remove the spark plug for the cylinder the
valve spring and seal are to be removed from.
(4) Apply shop air to the cylinder to hold the
valves in place when the spring is removed.NOTE: All six valve springs and seals are removed
in the same manner; this procedure only covers
one valve seal and valve spring.
(5) Using Special Tool 8387 Valve Spring Compres-
sor, compress the valve spring.
NOTE: It may be necessary to tap the top of the
valve spring to loosen the spring retainers locks
enough to be removed.
(6) Remove the two spring retainer lock halves.
NOTE: the valve spring is under tension use care
when releasing the valve spring compressor.
(7) Remove the valve spring compressor.
(8) Remove the spring retainer, and the spring.
(9) Remove the valve stem seal.
NOTE: The valve stem seals are common between
intake and exhaust.
INSTALLATION
NOTE: All six valve springs and seals are removed
in the same manner; this procedure only covers
one valve seal and valve spring.
(1) Apply shop air to the cylinder to hold the
valves in place while the spring is installed.
NOTE: The valve stem seals are common between
intake and exhaust.
(2) Install the valve stem seal.
(3) Install the spring retainer, and the spring.
(4) Using Special Tool 8387 Valve Spring Compres-
sor, compress the valve spring.
(5) Install the two spring retainer lock halves.
NOTE: the valve spring is under tension use care
when releasing the valve spring compressor.
(6) Remove the valve spring compressor.
(7) Disconnect the shop air to the cylinder.
(8) Install the spark plug for the cylinder the valve
spring and seal was installed on.
(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.
Fig. 30 Rocker Arm - Installation
1 - CAMSHAFT
2 - SPECIAL TOOL 8516
9 - 38 ENGINE - 3.7LKJ
ROCKER ARM (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