2002 JEEP LIBERTY eco

AIR CLEANER ELEMENT
REMOVAL - 3.7L
Housing removal is not necessary for element (fil-
ter) replacement.
(1) Pry up 2 spring clips (Fig. 3) from front of
housing cover (spring clips retain cover to housing).
(2) Release housing cover from 4 locating tabs
located on rear of housing, and remove cover.
(3) Remove air cleaner element (filter) from hous-
ing.
(4) Clean inside of housing before replacing ele-
ment.
INSTALLATION - 3.7L
(1) Install element into housing.
(2) Position housing cover into housing locating
tabs.
(3) Pry up spring clips and lock cover to housing.
If any air filter, air resonator, air intake tubes or
air filter housing clamps had been loosened or
removed, tighten them to 5 N´m (40 in. lbs.) torque.
CYLINDER HEAD - LEFT
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.
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.
Fig. 3 AIR CLEANER ELEMENT - 3.7L
1 - AIR INTAKE HOSE
2 - HOSE CLAMP
3 - COVER
4 - CLIPS (2)
KJENGINE - 3.7L 9 - 19

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.
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 the negative cable from the battery.
(2) Raise the vehicle on a hoist.
(3) Disconnect the exhaust pipe at the left 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 in this section.
(7) Remove the cylinder head cover. Refer to proce-
dure in this section.
(8) Remove the fan shroud and fan blade assembly.
Refer to COOLING SYSTEM.
(9) Remove accessory drive belt. Refer to COOL-
ING SYSTEM.
(10) Remove the power steering pump and set
aside.
(11) Rotate the crankshaft until the damper timing
mark is aligned with TDC indicator mark (Fig. 4).
(12) Verify the V6 mark on the camshaft sprocket
is at the 12 o'clock position (Fig. 5). Rotate the crank-
shaft one turn if necessary.
(13) Remove the crankshaft damper. Refer to Pro-
cedure.
(14) Remove the timing chain cover. Refer to pro-
cedure.
Fig. 4 Engine Top Dead Center
1 - TIMING CHAIN COVER
2 - CRANKSHAFT TIMING MARKS
9 - 20 ENGINE - 3.7LKJ
CYLINDER HEAD - LEFT (Continued)

(15) Lock the secondary timing chains to the idler
sprocket using Special Tool 8429 Timing Chain Hold-
ing Fixture (Fig. 6).
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 left side secondary chain ten-
sioner. Refer to Timing Chain and Sprockets.
(18) Remove the cylinder head access plug (Fig. 7).
(19) Remove the left side secondary chain guide.
Refer to Timing Chain and Sprockets.
(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.
NOTE: The cylinder head is attached to the cylinder
block with twelve bolts.
Fig. 5 Camshaft Sprocket V6 Marks
1 - LEFT CYLINDER HEAD
2 - RIGHT CYLINDER HEAD
Fig. 6 Using Special Tool 8429
1 - SPECIAL TOOL 8429
2 - CAMSHAFT CHAIN
3 - CRANKSHAFT TIMING GEAR
KJENGINE - 3.7L 9 - 21
CYLINDER HEAD - LEFT (Continued)

(4) Lubricate the cylinder head bolt threads with
clean engine oil and install the eight M11 bolts.
(5) Coat the four M8 cylinder head bolts with
MopartLock and Seal Adhesivethen install the
bolts.
NOTE: 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, 27 N´m (20 ft. lbs.).
²Step 2: Verify that bolts 1±10, all reached 27
N´m (20 ft. lbs.), by repeating step-1 without loosen-
ing the bolts. Tighten bolts 11 thru 14 to 14 N´m (10
ft. lbs.).
²Step 3: Tighten bolts 1±10, 90 degrees (Fig. 11).
²Step 4: Tighten bolts 1±10, 90 degrees, again.
Tighten bolts 11±14, 26 N´m (19 ft. 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-torqueing of bolt
resulting in bolt failure.
(8) Install the camshaft drive gear retaining bolt.
(9) Install the left side secondary chain guide.(10) Install the cylinder head access plug.
(11) Re-set and Install the left 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 the power steering pump.
(16) Install the fan blade assembly and fan
shroud.
(17) Install the cylinder head cover.
(18) Install the intake manifold.
(19) Refill the cooling system
(20) Raise the vehicle.
(21) Install the exhaust pipe onto the left exhaust
manifold.
(22) Lower the vehicle.
(23) Connect the negative cable to the battery.
(24) 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.
Fig. 10 Proper Tool Usage For Surface Preparation
1 - PLASTIC/WOOD SCRAPERFig. 11 CYLINDER HEAD TIGHTENING SEQUENCE
KJENGINE - 3.7L 9 - 23
CYLINDER HEAD - LEFT (Continued)

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
extension, requiring timing chain cover removal to
reset the tensioner ratchet.
(1) Remove cylinder head cover. Refer to CYLIN-
DER 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 (Located on the right side camshaft
sprocket) for any reason, Severe damage will occur
to the target wheel resulting in a vehicle no start
condition.
(4) Loosen butDO NOTremove the camshaft
sprocket retaining bolt. Leave the bolt snug against
the 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 (Fig. 12).
(6) Hold the camshaft with Special Tool 8428 Cam-
shaft Wrench, while removing the camshaft sprocket
bolt and sprocket (Fig. 13).
(7) Using Special Tool 8428 Camshaft Wrench,
gently allow the camshaft to rotate 5É clockwise until
the camshaft is in the neutral position (no valve
load).
(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.
Fig. 12 SECURING TIMING CHAIN TENSIONERS
USING TIMING CHAIN WEDGE Ð Typical
1 - SPECIAL TOOL 8379
2 - CAMSHAFT SPROCKET
3 - CAMSHAFT SPROCKET BOLT
Fig. 13 Special Tool 8428
1 - Camshaft hole
2 - Special Tool 8428
9 - 24 ENGINE - 3.7LKJ
CAMSHAFT(S) (Continued)

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. 19).
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 (Fig.
20).
(4) Using the valve spring compressor, compress
the spring and install the two valve spring retainer
halves.(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. 21).
(8) Position the hydraulic lash adjusters and
rocker arms.
Fig. 19 Testing Valve Springs
1 - SPECIAL TOOL C-647
Fig. 20 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 - 28 ENGINE - 3.7LKJ
INTAKE/EXHAUST VALVES & SEATS (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)