2002 JEEP LIBERTY ENGINE ASSEMBLY

CAUTION: Care should be taken not to damage
camshaft target wheel. Do not hold target wheel
while loosening or tightening camshaft sprocket.
Do not place the target wheel near a magnetic
source of any kind. A damaged or magnetized tar-
get wheel could cause a vehicle no start condition.
CAUTION: Do not forcefully rotate the camshafts or
crankshaft independently of each other. Damaging
intake valve to piston contact will occur. Ensure
negative battery cable is disconnected to guard
against accidental starter engagement.
(13) Remove left and right camshaft sprocket bolts.
(14) While holding the left camshaft steel tube
with Special Tool 8428 Camshaft Wrench, remove the
left camshaft sprocket. Slowly rotate the camshaft
approximately 5 degrees clockwise to a neutral posi-
tion.
(15) While holding the right camshaft steel tube
with Special Tool 8428 Camshaft Wrench, remove the
right camshaft sprocket.
(16) Remove idler sprocket assembly bolt.
(17) Slide the idler sprocket assembly and crank
sprocket forward simultaneously to remove the pri-
mary and secondary chains.
(18) Remove both pivoting tensioner arms and
chain guides.
(19) Remove chain tensioner.
INSPECTION
Inspect the following components:
²Sprockets for excessive tooth wear. Some tooth
markings are normal and not a cause for sprocket
replacement.
²Idler sprocket assembly bushing and shaft for
excessive wear.
²Idler sprocket assembly spline joint. The joint
should be tight with no backlash or axial movement.
²Chain guides and tensioner arms. Replace these
parts if grooving in plastic face is more than 1 mm
(0.039 in.) deep. If plastic face is severely grooved or
melted, the tensioner lube jet may be clogged. The
tensioner should be replaced.
²Secondary chain tensioner piston and ratcheting
device. Inspect for evidence of heavy contact between
tensioner piston and tensioner arm. If this condition
exist the tensioner tensioner arm and chain should
be replaced.
²Primary chain tensioner plastic faces. Replace as
required.
Fig. 105 CAMSHAFT POSITION SENSOR
1 - CYLINDER HEAD
2 - CAMSAHFT POSITION SENSOR
2 - SCREW
Fig. 106 Crankshaft Position Sensor
1 - CRANKSHAFT POSITION SENSOR
2 - CYLINDER HEAD COVER
3 - CAMSHAFT POSITION SENSOR
4 - RIGHT SIDE CYLINDER BLOCK
KJENGINE - 3.7L 9 - 79
TIMING BELT/CHAIN AND SPROCKET(S (Continued)

INSTALLATION
(1) Using a vise, lightly compress the secondary
chain tensioner piston until the piston step is flush
with the tensioner body. Using a pin or suitable tool,
release ratchet pawl by pulling pawl back against
spring force through access hole on side of tensioner.
While continuing to hold pawl back, Push ratchet
device to approximately 2 mm from the tensioner
body. Install Special Tool 8514 lock pin into hole on
front of tensioner (Fig. 107). Slowly open vise to
transfer piston spring force to lock pin.
(2) Position primary chain tensioner over oil pump
and insert bolts into lower two holes on tensioner
bracket. Tighten bolts to 28 N´m (250 in. lbs.).
(3) Install right side chain tensioner arm. Apply
MopartLock N, Seal to torxtbolt, tighten bolt to 28
N´m (250 in. lbs.).
CAUTION: The silver bolts retain the guides to the
cylinder heads and the black bolts retain the guides
to the engine block.
(4) Install the left side chain guide. Tighten the
bolts to 28 N´m (250 in. lbs.).
(5) Install left side chain tensioner arm. Apply
MopartLock N, Seal to torxtbolt, tighten bolt to 28
N´m (250 in. lbs.).(6) Install the right side chain guide. Tighten the
bolts to 28 N´m (250 in. lbs.).
(7) Install both secondary chains onto the idler
sprocket. Align two plated links on the secondary
chains to be visible through the two lower openings
on the idler sprocket (4 o'clock and 8 o'clock). Once
the secondary timing chains are installed, position
special tool 8429 to hold chains in place for installa-
tion.
(8) Align primary chain double plated links with
the timing mark at 12 o'clock on the idler sprocket.
Align the primary chain single plated link with the
timing mark at 6 o'clock on the crankshaft sprocket.
(9) Lubricate idler shaft and bushings with clean
engine oil.
NOTE: The idler sprocket must be timed to the
counterbalance shaft drive gear before the idler
sprocket is fully seated.
(10) Install all chains, crankshaft sprocket, and
idler sprocket as an assembly (Fig. 108). After guid-
ing both secondary chains through the block and cyl-
inder head openings, affix chains with a elastic strap
or the equivalent, This will maintain tension on
chains to aid in installation. Align the timing mark
on the idler sprocket to the timing mark on the coun-
terbalance shaft drive gear, then seat idler sprocket
fully (Fig. 109). Before installing idler sprocket bolt,
lubricate washer with oil, and tighten idler sprocket
assembly retaining bolt to 34 N´m (25 ft. lbs.).
Fig. 107 Resetting Secondary Chain Tensioners
1 - VISE
2 - INSERT LOCK PIN
3 - RATCHET PAWL
4 - RATCHET
5 - PISTON
Fig. 108 Installing Idler Gear, Primary and
Secondary Timing Chains
1 - SPECIAL TOOL 8429
2 - PRIMARY CHAIN IDLER SPROCKET
3 - CRANKSHAFT SPROCKET
9 - 80 ENGINE - 3.7LKJ
TIMING BELT/CHAIN AND SPROCKET(S (Continued)

(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)

ENGINE
TABLE OF CONTENTS
page page
ENGINE - 2.4L
DESCRIPTION..........................3
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE
TEST................................3
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE TEST.........3
DIAGNOSIS AND TESTING - ENGINE OIL
LEAK INSPECTION.....................4
DIAGNOSIS AND TESTING - ENGINE.......5
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - PERFORMANCE............5
DIAGNOSIS AND TESTING - ENGINE
MECHANICAL.........................7
STANDARD PROCEDURE
STANDARD PROCEDURE - ENGINE CORE
AND OIL GALLERY PLUGS...............9
STANDARD PROCEDURE - REPAIR OF
DAMAGED OR WORN THREADS..........9
STANDARD PROCEDURE - HYDROSTATIC
LOCKED ENGINE......................9
STANDARD PROCEDURE - FORM-IN-
PLACE GASKETS AND SEALERS.........10
STANDARD PROCEDURE - ENGINE
GASKET SURFACE PREPARATION........11
STANDARD PROCEDURE - MEASURING
BEARING CLEARANCE USING
PLASTIGAGE.........................11
REMOVAL - ENGINE ASSEMBLY...........12
INSTALLATION - ENGINE ASSEMBLY........12
SPECIFICATIONS
SPECIFICATIONS - 2.4L ENGINE.........13
SPECIFICATIONS - TORQUE............16
SPECIAL TOOLS
2.4L ENGINE.........................17
AIR CLEANER ELEMENT
REMOVAL - 2.4L........................19
INSTALLATION - 2.4L....................19
CYLINDER HEAD
DESCRIPTION.........................19
OPERATION...........................19
DIAGNOSIS AND TESTING - CYLINDER HEAD
GASKET............................19
REMOVAL - CYLINDER HEAD.............20
CLEANING............................20
INSPECTION..........................21
INSTALLATION - CYLINDER HEAD..........21CAMSHAFT OIL SEAL(S)
REMOVAL.............................22
INSTALLATION.........................22
CAMSHAFT(S)
DESCRIPTION.........................23
OPERATION...........................23
STANDARD PROCEDURE - CAMSHAFT
END-PLAY...........................23
REMOVAL.............................24
CLEANING............................24
INSPECTION..........................25
INSTALLATION.........................25
CYLINDER HEAD COVER
REMOVAL.............................26
CLEANING............................26
INSPECTION..........................26
INSTALLATION.........................26
INTAKE/EXHAUST VALVES & SEATS
DESCRIPTION.........................27
CLEANING............................27
VALVE SPRINGS
REMOVAL
REMOVAL - CYLINDER HEAD ON.........27
REMOVAL - CYLINDER HEAD OFF........27
INSPECTION..........................28
INSTALLATION
INSTALLATION - CYLINDER HEAD ON.....28
INSTALLATION - CYLINDER HEAD OFF....28
HYDRAULIC LIFTERS
DIAGNOSIS AND TESTING - LASH ADJUSTER
(TAPPET) NOISE DIAGNOSIS............28
REMOVAL.............................29
INSTALLATION.........................29
ROCKER ARMS
REMOVAL.............................29
INSPECTION..........................30
INSTALLATION.........................30
ENGINE BLOCK
DESCRIPTION.........................30
STANDARD PROCEDURE
STANDARD PROCEDURE - PISTON TO
CYLINDER BORE FITTING..............30
STANDARD PROCEDURE - CYLINDER
BORE HONING.......................31
CLEANING............................31
INSPECTION..........................32
CONNECTING ROD BEARINGS
STANDARD PROCEDURE
CONNECTING ROD - FITTING...........32
KJENGINE 9s - 1

CRANKSHAFT
DESCRIPTION.........................32
OPERATION...........................33
STANDARD PROCEDURE - CRANKSHAFT
ENDPLAY ...........................33
REMOVAL.............................33
INSPECTION..........................34
INSTALLATION.........................34
CRANKSHAFT MAIN BEARINGS
STANDARD PROCEDURE - MAIN BEARING -
FITTING.............................35
CRANKSHAFT OIL SEAL - FRONT
REMOVAL.............................37
INSTALLATION.........................37
CRANKSHAFT OIL SEAL - REAR
REMOVAL.............................38
INSTALLATION.........................39
PISTON & CONNECTING ROD
DESCRIPTION.........................40
OPERATION...........................40
REMOVAL.............................40
INSTALLATION.........................41
PISTON RINGS
STANDARD PROCEDURE
PISTON RING - FITTING................42
VIBRATION DAMPER
REMOVAL.............................43
INSTALLATION.........................43
STRUCTURAL COLLAR
REMOVAL.............................44
INSTALLATION.........................44
ENGINE MOUNTING
DESCRIPTION.........................44
FRONT MOUNT
REMOVAL.............................44
INSTALLATION.........................44
REAR MOUNT
REMOVAL.............................45
INSTALLATION.........................45
LUBRICATION
DESCRIPTION.........................46
OPERATION...........................46
DIAGNOSIS AND TESTING - ENGINE OIL
PRESSURE CHECKING.................46
OIL
STANDARD PROCEDURE
ENGINE OIL LEVEL CHECK.............47
STANDARD PROCEDURE - ENGINE OIL
AND FILTER CHANGE..................47
OIL FILTER
DESCRIPTION.........................47
REMOVAL.............................47
INSTALLATION.........................47
OIL PAN
REMOVAL.............................48INSTALLATION.........................48
OIL PRESSURE SENSOR/SWITCH
DESCRIPTION.........................48
OPERATION...........................48
OIL PUMP
REMOVAL.............................49
DISASSEMBLY.........................49
CLEANING............................49
INSPECTION..........................50
ASSEMBLY............................50
INSTALLATION.........................50
INTAKE MANIFOLD
DESCRIPTION.........................51
OPERATION...........................51
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKS.....................51
REMOVAL.............................52
INSPECTION..........................52
INSTALLATION.........................52
EXHAUST MANIFOLD
DESCRIPTION.........................53
OPERATION...........................53
REMOVAL.............................53
CLEANING............................53
INSPECTION..........................53
INSTALLATION.........................53
TIMING BELT COVER(S)
REMOVAL.............................53
INSTALLATION.........................53
TIMING BELT AND SPROCKET(S)
REMOVAL
REMOVAL - TIMING BELT...............55
REMOVAL - CRANKSHAFT SPROCKET....55
CLEANING............................55
INSTALLATION
INSTALLATION - CRANKSHAFT SPROCKET . 56
INSTALLATION - TIMING BELT...........56
TIMING BELT TENSIONER & PULLEY
REMOVAL.............................59
INSTALLATION.........................59
BALANCE SHAFT
DESCRIPTION.........................59
OPERATION...........................59
REMOVAL.............................60
INSTALLATION
BALANCE SHAFT TIMING...............61
BALANCE SHAFT CARRIER
REMOVAL.............................64
INSTALLATION.........................64
BALANCE SHAFT CHAIN
REMOVAL.............................64
INSTALLATION.........................64
9s - 2 ENGINEKJ

(7) Crank engine until maximum pressure is
reached on gage. Record this pressure as #1 cylinder
pressure.
(8) Repeat the previous step for all remaining cyl-
inders.
(9) Compression should not be less than 689 kPa
(100 psi) and not vary more than 25 percent from cyl-
inder to cylinder.
(10) If one or more cylinders have abnormally low
compression pressures, repeat the compression test.
(11) If the same cylinder or cylinders repeat an
abnormally low reading on the second compression
test, it could indicate the existence of a problem in
the cylinder in question.The recommended com-
pression pressures are to be used only as a
guide to diagnosing engine problems. An engine
should not be disassembled to determine the
cause of low compression unless some malfunc-
tion is present.
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
INSPECTION
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair as necessary.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.
(5)If the oil leak source is not positively
identified at this time, proceed with the air leak
detection test method as follows:
²Disconnect the fresh air hose (make-up air) at
the cylinder head cover and plug or cap the nipple on
the cover.
²Remove the PCV valve hose from the cylinder
head cover. Cap or plug the PCV valve nipple on the
cover.
²Attach an air hose with pressure gauge and reg-
ulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.²Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provides the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
²If the leakage occurs at the crankshaft rear oil
seal area, refer to the section, Inspection for Rear
Seal Area Leak.
(6) If no leaks are detected, turn off the air supply.
Remove the air hose, all plugs, and caps. Install the
PCV valve and fresh air hose (make-up air). Proceed
to next step.
(7) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
NOTE: If oil leakage is observed at the dipstick tube
to block location; remove the tube, clean and reseal
using MoparTStud & Bearing Mount (press fit tube
applications only), and for O-ring style tubes,
remove tube and replace the O-ring seal.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak. If a leak is
present in this area, remove transmission for further
inspection.
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, oil gallery cup
plug, bedplate to cylinder block mating surfaces
and seal bore. See proper repair procedures for
these items.
(4) If no leaks are detected, pressurize the crank-
case as previously described.
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is
detected between the crankshaft and seal while
slowly turning the crankshaft, it is possible the
9s - 4 ENGINEKJ
ENGINE - 2.4L (Continued)

DIAGNOSIS AND TESTING - ENGINE MECHANICAL
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES 1. High or low oil level in
crankcase.1. Check and correct engine oil
level.
2. Thin or diluted oil. 2. Change oil to correct viscosity.
3. Thick oil 3. (a) Change engine oil and filter.
(b) Run engine to operating
temperature.
(c) Change engine oil and filter
again.
4. Low oil pressure. 4. Check and correct engine oil
level.
5. Dirt in tappets/lash adjusters. 5. Replace rocker arm/hydraulic
lash adjuster assembly.
6. Worn rocker arms. 6. Inspect oil supply to rocker arms.
7. Worn tappets/lash adjusters. 7. Install new rocker arm/hydraulic
lash adjuster assembly.
8. Worn valve guides. 8. Replace cylinder head assembly.
9. Excessive runout of valve seats
on valve faces.9. Grind valve seats and valves.
10. Missing adjuster pivot. 10. Replace rocker arm/hydraulic
lash adjuster assembly.
CONNECTING ROD NOISE 1. Insufficient oil supply. 1. Check engine oil level.
2. Low oil pressure. 2. Check engine oil level. Inspect oil
pump relief valve and spring.
3. Thin or diluted oil. 3. Change oil to correct viscosity.
4. Thick oil 4. (a) Change engine oil and filter.
(b) Run engine to operating
temperature.
(c) Change engine oil and filter
again.
5. Excessive bearing clearance. 5. Measure bearings for correct
clearance. Repair as necessary.
6. Connecting rod journal
out-of-round.6. Replace crankshaft or grind
surface.
7. Misaligned connecting rods. 7. Replace bent connecting rods.
KJENGINE9s-7
ENGINE - 2.4L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
OIL CONSUMPTION OR SPARK
PLUGS FOULED1. PCV system malfunction. 1. Check system and repair as
necessary. (Refer to 25 -
EMISSIONS CONTROL/
EVAPORATIVE EMISSIONS/PCV
VALVE - DIAGNOSIS AND
TESTING)
2. Worn, scuffed or broken rings. 2. Hone cylinder bores. Install new
rings.
3. Carbon in oil ring slots. 3. Install new rings.
4. Rings fitted too tightly in grooves. 4. Remove rings and check
grooves. If groove is not proper
width, replace piston.
5. Worn valve guide(s). 5. Replace cylinder head assembly.
6. Valve stem seal(s) worn or
damaged.6. Replace seal(s).
STANDARD PROCEDURE
STANDARD PROCEDURE - ENGINE CORE AND
OIL GALLERY PLUGS
Using a blunt tool such as a drift and a hammer,
strike the bottom edge of the cup plug. With the cup
plug rotated, grasp firmly with pliers or other suit-
able tool and remove plug (Fig. 2).
CAUTION: Do not drive cup plug into the casting as
restricted cooling can result and cause serious
engine problems.Thoroughly clean inside of cup plug hole in cylin-
der block or head. Be sure to remove old sealer.
Lightly coat inside of cup plug hole with Mopart
Stud and Bearing Mount. Make certain the new plug
is cleaned of all oil or grease. Using proper drive
plug, drive plug into hole so that the sharp edge of
the plug is at least 0.5 mm (0.020 in.) inside the
lead-in chamfer.
It is not necessary to wait for curing of the sealant.
The cooling system can be refilled and the vehicle
placed in service immediately.
STANDARD PROCEDURE - REPAIR OF
DAMAGED OR WORN THREADS
Damaged or worn threads (excluding spark plug
and camshaft bearing cap attaching threads) can be
repaired. Essentially, this repair consists of drilling
out worn or damaged threads, tapping the hole with
a special Heli-Coil Tap, (or equivalent) and installing
an insert into the tapped hole. This brings the hole
back to its original thread size.
CAUTION: Be sure that the tapped holes maintain
the original center line.
Heli-Coil tools and inserts are readily available
from automotive parts jobbers.
STANDARD PROCEDURE - HYDROSTATIC
LOCKED ENGINE
When an engine is suspected to be hydrostatically
locked, regardless of what caused the problem, the
following steps should be used.
CAUTION: DO NOT use starter motor to rotate the
engine, severe damage may occur.
Fig. 2 Core Hole Plug Removal
1 - CYLINDER BLOCK
2 - REMOVE PLUG WITH PLIERS
3 - STRIKE HERE WITH HAMMER
4 - DRIFT PUNCH
5 - CUP PLUG
KJENGINE9s-9
ENGINE - 2.4L (Continued)