2002 JEEP LIBERTY Engine

DESCRIPTION SPECIFICATION
Cylinder Head Warpage
(Flatness) 0.0508 mm (0.002 in.)
OIL PUMP
Clearance Over
Rotors/End Face(MAX)0.035 - 0.095 mm
(0.0014 - 0.0038 in.)
Cover Out - of -Flat
(MAX)0.025 mm (0.001 in.)
Inner and Outer Rotor
Thickness 12.02 mm (0.4731 in.)
Outer Rotor Diameter
(MAX).235 mm (.0093 in.)
Outer Rotor Diameter
(MIN)85.925 mm (0.400 in.)
Tip Clearance Between
Rotors
(MAX) 0.150 mm (0.006 in.)
OIL PRESSURE
At Curb Idle Speed
(MIN)*25 kPa (4 psi)
@ 3000 rpm 170 - 758 kPa (25 - 110
psi)
* CAUTION: If pressure is zero at curb idle, DO
NOT run engine at 3000 rpm.
SPECIAL TOOLS
3.7L ENGINE
Spanner Wrench 6958
Adapter Pins 8346
Front Crankshaft Seal Remover 8511
Front Crankshaft Seal Installer 8348
Handle C-4171
KJENGINE - 3.7L 9 - 15
ENGINE - 3.7L (Continued)

Rear Crankshaft Seal Installer 8349
Rear Crankshaft Seal Remover 8506
Connecting Rod Guides 8507
Crankshaft Damper Installer 8512
Puller 1026
Crankshaft Damper Removal Insert 8513
Chain Tensioner Wedge 8379
Chain Tensioner Pins 8514
9 - 16 ENGINE - 3.7LKJ
ENGINE - 3.7L (Continued)

VALVE SPRING COMPRESSOR 8426
ENGINE LIFTING FIXTURE 8427
CAMSHAFT HOLDER 8428
HOLDER SECONDARY CAMSHAFT CHAIN 8429
Remover, Rocker Arm 8516
Idler Shaft Remover 8517
Valve Spring Compressor Adapters 8519
KJENGINE - 3.7L 9 - 17
ENGINE - 3.7L (Continued)

INSTALLER - REMOVER - COUNTER BALANCE
SHAFT 8641
Valve Spring Tester C-647
Dial Indicator C-3339
Valve Spring Compressor C-3422-B
Bore Size Indicator C-119
Oil Pressure Gauge C-3292
Piston Ring Compressor C-385
Pressure Tester Kit 7700
Bloc±Chek±Kit C-3685±A
9 - 18 ENGINE - 3.7LKJ
ENGINE - 3.7L (Continued)

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)

(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, due to the design of the cylin-
der 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. 8). (Refer
to 9 - ENGINE - STANDARD PROCEDURE)
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. The M8 head
bolts, should not be reused. Use new M8 bolts.
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 (Fig. 9).
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 (Fig. 10).(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 smaller cylinder head mounting
bolts require sealant to be added to them before
installing. Failure to do so may cause leaks.
Fig. 7 Cylinder Head Access Plugs
1 - RIGHT CYLINDER HEAD ACCESS PLUG
2 - LEFT CYLINDER HEAD ACCESS PLUG
Fig. 8 Proper Tool Usage For Surface Preparation
1 - PLASTIC/WOOD SCRAPER
Fig. 9 Checking Cylinder Head Bolts for Stretching
(Necking)
1 - STRETCHED BOLT
2 - THREADS ARE NOT STRAIGHT ON LINE
3 - THREADS ARE STRAIGHT ON LINE
4 - UNSTRETCHED BOLT
9 - 22 ENGINE - 3.7LKJ
CYLINDER HEAD - LEFT (Continued)