2002 JEEP LIBERTY light

NOTE: It will be necessary to slightly rotate cam-
shafts for sprocket installation.
(11) Align left camshaft sprocket ªLº dot to plated
link on chain.
(12) Align right camshaft sprocket ªRº dot to
plated link on chain.
CAUTION: Remove excess oil from the camshaft
sprocket bolt. Failure to do so can result in over-
torque of bolt resulting in bolt failure.
(13) Remove Special Tool 8429, then attach both
sprockets to camshafts. Remove excess oil from bolts,
then Install sprocket bolts, but do not tighten at this
time.
(14) Verify that all plated links are aligned with
the marks on all sprockets and the ªV6º marks on
camshaft sprockets are at the 12 o'clock position.
CAUTION: Ensure the plate between the left sec-
ondary chain tensioner and block is correctly
installed.
(15) Install both secondary chain tensioners.
Tighten bolts to 28 N´m (250 in. lbs.).
NOTE: Left and right secondary chain tensioners
are not common.(16) Remove all locking pins (3) from tensioners.
CAUTION: After pulling locking pins out of each
tensioner, DO NOT manually extend the tensioner(s)
ratchet. Doing so will over tension the chains,
resulting in noise and/or high timing chain loads.
(17) Using Special Tool 6958, Spanner with Adap-
tor Pins 8346, tighten left (Fig. 110) and right (Fig.
111). camshaft sprocket bolts to 122 N´m (90 ft. lbs.).
(18) Rotate engine two full revolutions. Verify tim-
ing marks are at the follow locations:
²primary chain idler sprocket dot is at 12 o'clock
²primary chain crankshaft sprocket dot is at 6
o'clock
²secondary chain camshaft sprockets ªV6º marks
are at 12 o'clock
²counterbalancer shaft drive gear dot is aligned
to the idler sprocket gear dot
(19) Lubricate all three chains with engine oil.
Fig. 109 COUNTERBALANCE SHAFT ALIGNMENT
MARKS
1 - COUNTERBALANCE SHAFT
2 - TIMING MARKS
3 - IDLER SPROCKET
Fig. 110 Tightening Left Side Camshaft Sprocket
Bolt
1 - TORQUE WRENCH
2 - CAMSHAFT SPROCKET
3 - LEFT CYLINDER HEAD
4 - SPECIAL TOOL 6958 SPANNER WITH ADAPTER PINS 8346
KJENGINE - 3.7L 9 - 81
TIMING BELT/CHAIN AND SPROCKET(S (Continued)

(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)

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)

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)

shown in (Fig. 34). Refer to for Engine Specifications
(Refer to 9 - ENGINE - SPECIFICATIONS). Correct
piston to bore clearance must be established in order
to assure quiet and economical operation.
NOTE: Pistons and cylinder bores should be mea-
sured at normal room temperature, 21ÉC (70ÉF).
STANDARD PROCEDURE - CYLINDER BORE
HONING
(1) Used carefully, the cylinder bore resizing hone,
recommended tool C-823 or equivalent, equipped
with 220 grit stones, is the best tool for this honing
procedure. In addition to deglazing, it will reduce
taper and out-of-round as well as removing light
scuffing, scoring or scratches. Usually a few strokes
will clean up a bore and maintain the required lim-
its.
(2) Deglazing of the cylinder walls may be done
using a cylinder surfacing hone, recommended toolC-3501 or equivalent, equipped with 280 grit stones,
if the cylinder bore is straight and round. 20±60
strokes depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Use a light
honing oil.Do not use engine or transmission oil,
mineral spirits or kerosene.Inspect cylinder walls
after each 20 strokes.
(3) Honing should be done by moving the hone up
and down fast enough to get a cross-hatch pattern.
When hone marksintersectat 40-60 degrees, the
cross hatch angle is most satisfactory for proper seat-
ing of rings (Fig. 36).
(4) A controlled hone motor speed between
200±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 40±60
degree angle. Faster up and down strokes increase
the cross-hatch angle.
(5) After honing, it is necessary that the block be
cleaned again to remove all traces of abrasive.
CAUTION: Ensure all abrasives are removed from
engine parts after honing. It is recommended that a
solution of soap and hot water be used with a
brush and the parts then thoroughly dried. The bore
can be considered clean when it can be wiped
clean with a white cloth and cloth remains clean.
Oil the bores after cleaning to prevent rusting.
CLEANING
Clean cylinder block thoroughly using a suitable
cleaning solvent.
Fig. 34 Checking Cylinder Bore -Typical
Fig. 35 Piston Measurement - Typical
Fig. 36 Cylinder Bore Cross-Hatch Pattern
1 - CROSS-HATCH PATTERN
2 - 40ɱ60É
KJENGINE9s-31
ENGINE BLOCK (Continued)

TIMING BELT AND
SPROCKET(S)
REMOVAL
REMOVAL - TIMING BELT
(1) Remove air cleaner upper cover, housing, and
clean air tube.
(2) Raise vehicle on hoist.
(3) Remove accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/BELT TENSION-
ERS - REMOVAL)
(4) Remove crankshaft vibration damper. (Refer to
9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL)
(5) Remove air conditioner/generator belt tensioner
and pulley assembly. (Refer to 7 - COOLING/ACCES-
SORY DRIVE/BELT TENSIONERS - REMOVAL)
(6) Remove timing belt lower front cover bolts and
remove cover. (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT / CHAIN COVER(S) - REMOVAL)
(7) Lower vehicle.
(8) Remove bolts attaching timing belt upper front
cover and remove cover. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT / CHAIN COVER(S)
- REMOVAL)
CAUTION: When aligning crankshaft and camshaft
timing marks always rotate engine from crankshaft.
Camshaft should not be rotated after timing belt is
removed. Damage to valve components may occur.
Always align timing marks before removing timing
belt.
(9) Before the removal of the timing belt, rotate
crankshaft until the TDC mark on oil pump housing
aligns with the TDC mark on crankshaft sprocket
(trailing edge of sprocket tooth) (Fig. 95).
NOTE: The crankshaft sprocket TDC mark is
located on the trailing edge of the sprocket tooth.
Failure to align trailing edge of sprocket tooth to
TDC mark on oil pump housing will cause the cam-
shaft timing marks to be misaligned.
(10) Install 6 mm Allen wrench into belt tensioner.
Before rotating the tensioner, insert the long end of a
1/8º or 3 mm Allen wrench into the pin hole on the
front of the tensioner (Fig. 96). While rotating the
tensioner counterclockwise, push in lightly on the
1/8º or 3 mm Allen wrench, until it slides into the
locking hole.
(11) Remove timing belt.
REMOVAL - CRANKSHAFT SPROCKET
(1) Disconnect negative battery cable.
(2) Remove timing belt (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL).
(3) Remove crankshaft sprocket using Special
Tools 6793 and insert C-4685-C2 (Fig. 97).
CLEANING
Do Not attempt to clean a timing belt. If contami-
nation from oil, grease, or coolants have occurred, the
timing belt should be replaced.
Clean all sprockets using a suitable solvent. Clean
all sprocket grooves of any debris.
Fig. 95 Crankshaft and Camshaft Timing
1 - CAMSHAFT TIMING MARKS
2 - CRANKSHAFT TDC MARKS
3 - TRAILING EDGE OF SPROCKET TOOTH
KJENGINE9s-55

(9) With balance shaft keyways pointing up (12
o'clock) slide the balance shaft sprocket onto the nose
of the balance shaft. The balance shaft may have to
be pushed in slightly to allow for clearance.
NOTE: THE TIMING MARK ON THE SPROCKET, THE
(LOWER) NICKEL PLATED LINK, AND THE ARROW
ON THE SIDE OF THE GEAR COVER SHOULD LINE
UP WHEN THE BALANCE SHAFTS ARE TIMED
CORRECTLY.
(10) If the sprockets are timed correctly, install the
balance shaft bolts and tighten to 28 N´m (250 in.
lbs.). A wood block placed between crankcase and
crankshaft counterbalance will prevent crankshaft
and gear rotation.(11)CHAIN TENSIONING:
(a) Install chain tensioner loosely assembled.
(b) Position guide on double ended stud making
sure tab on the guide fits into slot on the gear
cover. Install and tighten nut/washer assembly to
12 N´m (105 in. lbs.).
(c) Place a shim 1 mm (0.039 in.) thick x 70 mm
(2.75 in.) long or between tensioner and chain.
Push tensioner and shim up against the chain.
Apply firm pressure 2.5±3 Kg (5.5±6.6 lbs.)
directly behind the adjustment slot to take up
all slack.Chain must have shoe radius contact as
shown in (Fig. 115).
(d) With the load applied, tighten top tensioner
bolt first, then bottom pivot bolt. Tighten bolts to
12 N´m (105 in. lbs.). Remove shim.
(e) Install carrier covers and tighten screws to
12 N´m (105 in. lbs.).
(12) Install pick-up tube and oil pan.
(13) Fill engine crankcase with proper oil to cor-
rect level.
Fig. 114 Balance Shaft Timing
1 - MARK ON SPROCKET
2 - KEYWAYS UP
3 - ALIGN MARKS
4 - PLATED LINK
5 - PARTING LINE (BEDPLATE TO BLOCK)
6 - PLATED LINK
Fig. 115 Chain Tension Adjustment
1 - 1MM (0.039 IN.) SHIM
2 - TENSIONER (ADJUSTER) BOLT
3 - PIVOT BOLT
KJENGINE9s-63
BALANCE SHAFT (Continued)

EXHAUST SYSTEM
TABLE OF CONTENTS
page page
EXHAUST SYSTEM
DESCRIPTION..........................1
DIAGNOSIS AND TESTING - EXHAUST
SYSTEM.............................2
CATALYTIC CONVERTER
DESCRIPTION - CATALYTIC CONVERTER.....2
REMOVAL.............................2
INSPECTION...........................3
INSTALLATION..........................3CROSS-OVER PIPE
REMOVAL.............................3
INSTALLATION..........................3
HEAT SHIELDS
DESCRIPTION..........................4
MUFFLER
DESCRIPTION..........................4
REMOVAL.............................5
INSTALLATION..........................5
EXHAUST SYSTEM
DESCRIPTION
The basic exhaust system consists of an engine
exhaust manifold, exhaust down pipe, exhaust pipe,
exhaust heat shield(s), muffler and exhaust tailpipe
The exhaust system uses a single muffler.
The exhaust system must be properly aligned to
prevent stress, leakage and body contact. If the sys-
tem contacts any body panel, it will transfer objec-
tionable noises originating from the engine to the
body.
When inspecting an exhaust system, critically
inspect for cracked or loose joints, stripped screw or
bolt threads, corrosion damage and worn, cracked orbroken hangers. Replace all components that are
badly corroded or damaged. DO NOT attempt to
repair.
When replacement is required, use original equip-
ment parts (or equivalent). This will assure proper
alignment and provide acceptable exhaust noise lev-
els.
CAUTION: Avoid application of rust prevention com-
pounds or undercoating materials to exhaust sys-
tem floor pan exhaust heat shields. Light overspray
near the edges is permitted. Application of coating
will result in excessive floor pan temperatures and
objectionable fumes.
KJEXHAUST SYSTEM 11 - 1