2002 JEEP LIBERTY Tighten timing chain

(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)

crankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled.
(7) After the oil leak root cause and appropriate
corrective action have been identified, replace compo-
nent(s) as necessary.
DIAGNOSIS AND TESTING - ENGINE
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either
mechanical (e.g., a strange noise), or performance
(e.g., engine idles rough and stalls).Refer to the Engine Mechanical and the Engine
Performance diagnostic charts, for possible causes
and corrections of malfunctions (Refer to 9 - ENGINE
- DIAGNOSIS AND TESTING - MECHANICAL)
(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING
- PERFORMANCE).
For fuel system diagnosis, (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - DIAGNOSIS AND
TESTING).
Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can-
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following:
²Cylinder Compression Pressure Test
²Cylinder Combustion Pressure Leakage Test
²Engine Cylinder Head Gasket Failure Diagnosis
²Intake Manifold Leakage Diagnosis
²Lash Adjuster (Tappet) Noise Diagnosis
²Engine Oil Leak Inspection
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery. 1. Test battery. Charge or replace
as necessary. (Refer to 8 -
ELECTRICAL/BATTERY SYSTEM -
DIAGNOSIS AND TESTING)
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to terminals.
3. Faulty starter. 3. Test starting system. (Refer to 8 -
ELECTRICAL/STARTING -
DIAGNOSIS AND TESTING)
4. Faulty coil(s) or control unit. 4. Test and replace as needed.
(Refer to Appropriate Diagnostic
Information)
5. Incorrect spark plug gap. 5. Set gap. (Refer to 8 -
ELECTRICAL/IGNITION CONTROL
- SPECIFICATIONS)
6. Contamination in fuel system. 6. Clean system and replace fuel
filter.
7. Faulty fuel pump. 7. Test fuel pump and replace as
needed. (Refer to Appropriate
Diagnostic Information)
8. Incorrect engine timing. 8. Check for a skipped timing
belt/chain.
KJENGINE9s-5
ENGINE - 2.4L (Continued)

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 - CYLINDER HEAD
(1) Perform fuel system pressure release procedure
before attempting any repairs.(Refer to 14 -FUEL SYSTEM/FUEL DELIVERY - SPECIFICA-
TIONS)
(2) Disconnect battery negative cable.
(3) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(4) Remove air filter housing and inlet tube.
(5) Remove intake manifold.
(6) Remove heater tube support bracket from cyl-
inder head.
(7) Disconnect radiator upper and heater supply
hoses from water outlet connections.
(8) Remove accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
(9) Raise vehicle and remove exhaust pipe from
manifold.
(10) Remove power steering pump and set aside.
Do not disconnect lines.
(11) Remove accessory drive bracket
(12) Remove ignition coil and wires from engine.
(13) Disconnect cam sensor and fuel injector wir-
ing connectors.
(14) Remove timing belt and camshaft sprockets.
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT/CHAIN AND SPROCKETS - REMOVAL)
(15) Remove timing belt idler pulley and rear tim-
ing belt cover. (Refer to 9 - ENGINE/VALVE TIM-
ING/TIMING BELT / CHAIN COVER(S) -
REMOVAL)
(16) Remove cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL)
(17) Remove camshafts (Refer to 9 - ENGINE/
CYLINDER HEAD/CAMSHAFT(S) - REMOVAL).
NOTE: Identify rocker arm position to ensure cor-
rect re-installation in original position, if reused.
(18) Remove rocker arms. (Refer to 9 - ENGINE/
CYLINDER HEAD/ROCKER ARMS - REMOVAL).
(19) Remove cylinder head bolts in REVERSE
sequence of tightening.
(20) Remove cylinder head from engine block.
(21) Inspect and clean cylinder head. (Refer to 9 -
ENGINE/CYLINDER HEAD - INSPECTION) (Refer
to 9 - ENGINE/CYLINDER HEAD - CLEANING)
CLEANING
To ensure engine gasket sealing, proper surface
preparation must be performed, especially with the
use of aluminum engine components and multi-layer
steel cylinder head gaskets.
NOTE: Multi-Layer Steel (MLS) head gaskets require
a scratch free sealing surface.
9s - 20 ENGINEKJ
CYLINDER HEAD (Continued)

²Third All to 68 N´m (50 ft. lbs.)
CAUTION: Do not use a torque wrench for the fol-
lowing step.
²Fourth Turn an additional 1/4 Turn,
(5) Install rocker arms. (Refer to 9 - ENGINE/
CYLINDER HEAD/ROCKER ARMS - INSTALLA-
TION)
(6) Install camshafts. (Refer to 9 - ENGINE/CYL-
INDER HEAD/CAMSHAFT(S) - INSTALLATION).
(7) Install cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION)
(8) Install timing belt rear cover and timing belt
idler pulley. (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT / CHAIN COVER(S) - INSTALLA-
TION)
(9) Install timing belt and camshaft sprockets.
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT/CHAIN AND SPROCKETS - INSTALLATION)
(10) Connect cam sensor and fuel injectors wiring
connectors.(11) Install ignition coil and wires. Connect igni-
tion coil wiring connector.
(12) Install accessary drive bracket.
(13) Install power steering pump to cylinder head.
(14) Raise vehicle and install the exhaust pipe to
the manifold.
(15) Install accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION)
(16) Install heater tube support bracket to cylinder
head.
(17) Install intake manifold.
(18) Connect all vacuum lines, electrical wiring,
ground straps and fuel line.
(19) Fill cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(20) Connect battery negative cable.
CAMSHAFT OIL SEAL(S)
REMOVAL
(1) Remove timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL)
(2) Hold each camshaft sprocket with Special Tool
6847 while removing center bolt (Fig. 12).
(3) Remove camshaft sprockets.
(4) Remove exhaust camshaft target ring.
(5) Remove exhaust camshaft sensor.
CAUTION: Inspect sensor and target ring for exces-
sive wear. Clean sensor face and install new spacer
pad.
(6) Remove rear timing belt cover. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL)
(7) Remove camshaft seal using Special Tool
C-4679-A (Fig. 13).
CAUTION: Do not nick shaft seal surface or seal
bore.
INSTALLATION
NOTE: Clean and inspect sensor and target ring for
excessive wear. Clean sensor face and always
install a new spacer pad.
(1) Shaft seal surface must be free of varnish, dirt
or nicks. Polish with 400 grit paper if necessary.
(2) Install camshaft seals into cylinder head using
Special Tool MD-998306 until flush with head (Fig.
14).
Fig. 10 Cylinder Head Gasket Positioning
1 - PART NUMBER FACES UP
2 - NO. 1 CYLINDER
Fig. 11 Cylinder Head Tightening Sequence
9s - 22 ENGINEKJ
CYLINDER HEAD (Continued)

(3) Install timing belt rear cover. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION)
NOTE: Target ring tab should provide posative
snap-on fit on the camshaft.
(4) Install exhaust camshaft target ring with the
wordFRONTfacing forward.
(5) Install exhaust camshaft sensor.
(6) Install camshaft sprockets. Hold each sprocket
with Special Tool 6847 and tighten center bolt to 101
N´m (75 ft. lbs.).
(7) Install timing belt and front covers. (Refer to 9
- ENGINE/VALVE TIMING/TIMING BELT/CHAINAND SPROCKETS - INSTALLATION) (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION)
CAMSHAFT(S)
DESCRIPTION
Both nodular iron camshafts have six bearing jour-
nal surfaces and two cam lobes per cylinder (Fig. 15).
Flanges at the rear journals control camshaft end
play. Provision for a cam position sensor is located on
the exhaust camshaft on the front of the cylinder
head. A hydrodynamic oil seal is used for oil control
at the front of the camshaft.
OPERATION
The camshaft is driven by the crankshaft via drive
sprockets and belt. The camshaft has precisely
machined lobes to provide accurate valve timing and
duration.
STANDARD PROCEDURE - CAMSHAFT
END-PLAY
(1) Oil camshaft journals and install camshaft
WITHOUTcam follower assemblies. Install rear cam
caps and tighten screws to specified torque.
(2) Using a suitable tool, move camshaft as far
rearward as it will go.
(3) Zero dial indicator (Fig. 16).
(4) Move camshaft as far forward as it will go.
(5) Record reading on dial indicator. For end play
specification, (Refer to 9 - ENGINE - SPECIFICA-
TIONS).
(6) If end play is excessive, check cylinder head
and camshaft for wear; replace as necessary.
Fig. 12 Camshaft Sprocket - Removal/Installation
1 - SPECIAL TOOL 6847
Fig. 13 Camshaft Oil Seal - Removal With C-4679-A
1 - SPECIAL TOOL C-4679
Fig. 14 Camshaft Seal - Installation
1 - SPECIAL TOOL MD 998306
KJENGINE9s-23
CAMSHAFT OIL SEAL(S) (Continued)

INSPECTION
(1) Inspect camshaft bearing journals for damage
and binding (Fig. 19). If journals are binding, check
the cylinder head for damage. Also check cylinder
head oil holes for clogging.
(2) Check the cam lobe and bearing surfaces for
abnormal wear and damage. Replace camshaft if
defective.
NOTE: If camshaft is replaced due to lobe wear or
damage, always replace the rocker arms.
(3) Measure the lobe actual wear (unworn area -
wear zone = actual wear) (Fig. 19) and replace cam-
shaft if out of limit. Standard value is 0.0254 mm
(0.001 in.), wearlimitis 0.254 mm (0.010 in.).
INSTALLATION
CAUTION: Ensure that NONE of the pistons are at
top dead center when installing the camshafts.
(1) Lubricate all camshaft bearing journals, rocker
arms and camshaft lobes.
(2) Install all rocker arms in original positions, if
reused.
(3) Position camshafts on cylinder head bearing
journals. Install right and left camshaft bearing caps
No.2±5andright No. 6. Tighten M6 fasteners to 12
N´m (105 in. lbs.) in sequence shown in (Fig. 20).
(4) Apply MopartGasket Maker to No. 1 and No.
6 bearing caps (Fig. 21). Install bearing caps and
tighten M8 fasteners to 28 N´m (250 in. lbs.).NOTE: Bearing end caps must be installed before
seals can be installed.
(5) Install camshaft oil seals. (Refer to 9 -
ENGINE/CYLINDER HEAD/CAMSHAFT OIL
SEAL(S) - INSTALLATION)
(6) Install camshaft target magnet and camshaft
position sensor.
(7) Install cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION)
(8) Install timing belt rear cover and camshaft
sprocket. (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT / CHAIN COVER(S) - INSTALLA-
TION)
(9) Install timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - INSTALLATION)
Fig. 19 Checking Camshaft(s) for Wear
1 - UNWORN AREA
2 - ACTUAL WEAR
3 - BEARING JOURNAL
4 - LOBE
5 - WEAR ZONE
Fig. 20 Camshaft Bearing Cap Tightening Sequence
Fig. 21 Camshaft Bearing Cap Sealing
1 - 1.5 mm (.060 in.) DIAMETER BEAD OF MOPAR GASKET
MAKER
KJENGINE9s-25
CAMSHAFT(S) (Continued)

OPERATION
The crankshaft transfers force generated by com-
bustion within the cylinder to the flywheel or flex-
plate.
STANDARD PROCEDURE - CRANKSHAFT END
PLAY
(1) Using Dial Indicator C-3339 and Mounting
Post L-4438, attach to front of engine, locating probe
perpendicular on nose of crankshaft (Fig. 40).
(2) Move crankshaft all the way to the rear of its
travel.
(3) Zero the dial indicator.
(4) Move crankshaft all the way to the front and
read the dial indicator. Refer to Engine Specifica-
tions.
REMOVAL
NOTE: Crankshaft can not be removed when engine
is in vehicle.
(1) Remove engine assembly from vehicle. (Refer to
9 - ENGINE - REMOVAL)
(2) Remove flex plate and crankshaft rear oil seal.
(3) Mount engine on a repair stand.
(4) Drain engine oil and remove oil filter.
(5) Remove the oil pan. (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL)
(6) Remove the timing belt covers. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL)(7) Remove the timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL)
(8) Remove the oil pump. (Refer to 9 - ENGINE/
LUBRICATION/OIL PUMP - REMOVAL)
(9) Remove balance shafts and housing assembly.
(Refer to 9 - ENGINE/VALVE TIMING/BALANCE
SHAFT - REMOVAL)
(10) Remove all bedplate bolts from the engine
block (Fig. 41).
(11) Using a mallet gently tap the bedplate loose
from the engine block dowel pins.
CAUTION: Do not pry up on one side of the bed-
plate. Damage may occur to cylinder block to bed-
plate alignment and thrust bearing.
(12) Bedplate should be removed evenly from the
cylinder block dowel pins to prevent damage to the
dowel pins and thrust bearing.
(13) Lift out crankshaft from cylinder block. Do
not damage the main bearings or journals when
removing the crankshaft.
Fig. 39 Crankshaft - Typical
1 - MAIN BEARING JOURNALS
2 - COUNTER BALANCE WEIGHTS
Fig. 40 CHECKING CRANKSHAFT END PLAY
Fig. 41 Bedplate Bolt Tightenening Sequence
KJENGINE9s-33
CRANKSHAFT (Continued)

(6) Before installing the bolts the threads should
be oiled with clean engine oil, wipe off any excess oil.
(7) Install main bearing bedplate to engine block
bolts 11, 17, and 20 finger tight. Tighten these bolts
down together until the bedplate contacts the cylin-
der block.
(8) To ensure correct thrust bearing alignment,
perform the following steps:
²Step 1: Rotate crankshaft until number 4 piston
is at TDC.
²Step 2: Move crankshaft rearward to limits of
travel.
²Step 3: Then, move crankshaft forward to limits
of travel.
²Step 4: Wedge an appropriate tool between the
rear of the cylinder block(NOT BED PLATE)and
the rear crankshaft counterweight. This will hold the
crankshaft in it's furthest forward position.
²Step 5: Install and tighten bolts (1±10) in
sequence shown in (Fig. 45) to 41 N´m (30 ft. lbs.).
²Step 6: Remove wedge tool used to hold crank-
shaft.
(9) Tighten bolts (1±10) again to 41 N´m (30 ft.
lbs.) +1/4 turn in sequence shown in (Fig. 45).
(10) Install main bearing bedplate to engine block
bolts (11±20), and torque each bolt to 28 N´m (20 ft.
lbs.) in sequence shown in (Fig. 45).
(11) After the main bearing bedplate is installed,
check the crankshaft turning torque. The turning
torque should not exceed 5.6 N´m (50 in. lbs.).
(12) Install balance shafts and housing assembly.
(Refer to 9 - ENGINE/VALVE TIMING/BALANCE
SHAFT - INSTALLATION)
(13) Install the oil pump and pickup tube. (Refer
to 9 - ENGINE/LUBRICATION/OIL PUMP -
INSTALLATION)
(14) Install the timing belt rear cover. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION)
(15) Install the timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - INSTALLATION)
(16) Install the timing belt front covers. (Refer to 9
- ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION)
(17) Install engine support bracket.
(18) Install the oil pan. (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION)
(19) Install the oil filter.
(20) Install crankshaft rear oil seal. (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT OIL
SEAL - REAR - INSTALLATION)
(21) Install flex plate. Apply MopartLock & Seal
Adhesive to bolt threads and tighten to 95 N´m (70
ft. lbs.).(22) Install the engine assembly. (Refer to 9 -
ENGINE - INSTALLATION)
CRANKSHAFT MAIN
BEARINGS
STANDARD PROCEDURE - MAIN BEARING -
FITTING
For crankshaft specifications (Refer to 9 - ENGINE
- SPECIFICATIONS).
CRANKSHAFT MAIN BEARINGS
The crankshaft is supported in five main bearings.
All upper and lower bearing shells in the crankcase
have oil grooves. Crankshaft end play is controlled by
a flanged bearing on the number three main bearing
journal (Fig. 46).
Upper and lower Number 3 bearing halves are
flanged to carry the crankshaft thrust loads and are
NOT interchangeable with any other bearing halves
in the engine (Fig. 46). All bearing cap bolts removed
during service procedures are to be cleaned and oiled
before installation. Bearing shells are available in
standard and the following undersized: 0.025 mm
(0.001 in.) and 0.250 mm (0.010 in.). Never install an
undersize bearing that will reduce clearance below
specifications. Replace or machine the crankshaft as
necessary to obtain proper bearing clearances.
MAIN BEARING INSTALLATION
(1) Install the main bearing shells with the lubri-
cation groove in the cylinder block (Fig. 47).
Fig. 46 Main Bearing Identification
1 - OIL GROOVE
2 - MAIN BEARINGS
3 - OIL HOLE
KJENGINE9s-35
CRANKSHAFT (Continued)