2002 JEEP LIBERTY Workshop Manual

(3) Screw oil filter on until the gasket contacts
base. Tighten to 21 N´m (15 ft. lbs.).
OIL PAN
REMOVAL
(1) Remove air cleaner assembly.
(2) Raise vehicle on hoist and drain engine oil.
(3) Loosen the engine mount thru bolts.
(4) Disconnect exhaust pipe at manifold.
(5) Remove structural collar, if equipped.
(6) Remove front axle mounting bolts, and lower
axle as far possible, if equipped.
(7) Using suitable jack, raise engine as needed.
(8) Remove oil pan attaching bolts.
(9) Remove oil pan.
(10) Clean oil pan and all gasket surfaces.
INSTALLATION
(1) Install the oil pan gasket to the block.
(2) Apply a 3MM (1/8 inch) bead of MopartEngine
RTV at the oil pump to engine block parting line
(Fig. 80).
(3) Install pan and tighten the screws to 12 N´m
(105 in. lbs.).
(4) Lower engine, and remove jack.
(5) Tighten engine mount thru bolts.
(6) Raise the front axle into position, and reinstall
front axle mounting bolts. If equipped.
(7) Reconnect exhaust pipe to manifold.
(8) Install structural collar, if equipped.
(9) Lower vehicle.(10) Fill engine crankcase with proper oil to cor-
rect level.
(11) Reinstall air cleaner assembly.
OIL PRESSURE SENSOR/
SWITCH
DESCRIPTION
The 3±wire, electrical/mechanical engine oil pres-
sure sensor (sending unit) is located in an engine oil
pressure gallery.
OPERATION
The oil pressure sensor uses three circuits. They
are:
²A 5±volt power supply from the Powertrain Con-
trol Module (PCM)
²A sensor ground through the PCM's sensor
return
²A signal to the PCM relating to engine oil pres-
sure
The oil pressure sensor has a 3±wire electrical
function very much like the Manifold Absolute Pres-
sure (MAP) sensor. Meaning different pressures
relate to different output voltages.
A 5±volt supply is sent to the sensor from the PCM
to power up the sensor. The sensor returns a voltage
signal back to the PCM relating to engine oil pres-
sure. This signal is then transferred (bussed) to the
Fig. 79 2.4 OIL FILTERFig. 80 OIL PAN GASKET INSTALLATION
1 - SEALER LOCATION
9s - 48 ENGINEKJ
OIL FILTER (Continued)

instrument panel on either a CCD or PCI bus circuit
(depending on vehicle line) to operate the oil pressure
gauge and the check gauges lamp. Ground for the
sensor is provided by the PCM through a low-noise
sensor return.
OIL PUMP
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL)
(3) Remove timing belt rear cover. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL)
(4) Remove oil pan. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - REMOVAL)
(5) Remove crankshaft sprocket using Special
Tools 6793 and C-4685-C2 (Fig. 81).
(6) Remove crankshaft key (Fig. 82).
(7) Remove oil pick-up tube.
(8) Remove oil pump (Fig. 83) and front crankshaft
seal.
DISASSEMBLY
(1) To remove the relief valve, proceed as follows:
(a) Remove the threaded plug and gasket from
the oil pump.
(b) Remove spring and relief valve.
(2) Remove oil pump cover fasteners, and lift off
cover.
(3) Remove pump rotors.
(4) Wash all parts in a suitable solvent and
inspect carefully for damage or wear.
CLEANING
(1) Clean all parts thoroughly in a suitable sol-
vent.
Fig. 81 Crankshaft Sprocket - Removal
1 - SPECIAL TOOL 6793
2 - SPECIAL TOOL C-4685±C2
3 - CRANKSHAFT SPROCKET
Fig. 82 Crankshaft Key
1 - CRANKSHAFT KEY
Fig. 83 2.4L OIL PUMP
1 - BOLTS
2 - BOLTS
KJENGINE9s-49
OIL PRESSURE SENSOR/SWITCH (Continued)

INSPECTION
(1) Inspect the mating surface of the oil pump.
Surface should be smooth. Replace pump cover if
scratched or grooved.
(2) Lay a straightedge across the pump cover sur-
face (Fig. 84). If a 0.025 mm (0.001 in.) feeler gauge
can be inserted between cover and straight edge,
cover should be replaced.
(3) Measure thickness and diameter of outer rotor.
If outer rotor thickness measures 9.40 mm (0.370 in.)
or less (Fig. 85), or if the diameter is 79.95 mm
(3.148 in.) or less, replace outer rotor.
(4) If inner rotor measures 9.40 mm (0.370 in.) or
less replace inner rotor (Fig. 86).
ASSEMBLY
(1) Assemble pump, using new parts as required.
Install the inner rotor with chamfer facing the
cast iron oil pump cover.
(2) Prime oil pump before installation by filling
rotor cavity with engine oil.
(3) Install cover and tighten fasteners to 12 N´m
(105 in. lbs.).
CAUTION: Oil pump pressure relief valve must be
installed correctly or serious engine damage may
occur.
(4) Install relief valve, spring, gasket and cap.
Tighten cap to 41 N´m (30 ft. lbs.).
INSTALLATION
(1) Make sure all surfaces are clean and free of oil
and dirt.
(2) Apply MopartGasket Maker to oil pump as
shown in (Fig. 87). Install O-ring into oil pump body
discharge passage.
(3) Prime oil pump with engine oil before installa-
tion.
(4) Align oil pump rotor flats with flats on crank-
shaft. Install the oil pump to the block.
CAUTION: To align, the front crankshaft seal MUST
be out of pump, or damage may result.
(5) Install new front crankshaft seal using Special
Tool 6780 (Fig. 88).
(6) Install crankshaft key (Fig. 82).
CAUTION: The crankshaft sprocket is set to a pre-
determined depth from the factory for correct tim-
ing belt tracking. If removed, use of Special Tool
6792 is required to set the sprocket to original
installation depth. An incorrectly installed sprocket
will result in timing belt and engine damage.
Fig. 84 Checking Oil Pump Cover Flatness
1 - STRAIGHT EDGE
2 - FEELER GAUGE
3 - OIL PUMP COVER
Fig. 85 Measuring Outer Rotor Thickness
Fig. 86 Measuring Inner Rotor Thickness
9s - 50 ENGINEKJ
OIL PUMP (Continued)

(7) Install crankshaft sprocket using Special Tool
6792 (Fig. 89).
(8) Install oil pump pick-up tube.(9) Install oil pan. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - INSTALLATION)
(10) Install timing belt rear cover. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION)
(11) Install timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - INSTALLATION)
INTAKE MANIFOLD
DESCRIPTION
The intake manifold is a one piece composite mod-
ule that attaches to the cylinder head with fasteners.
The manifold is a long branch design to enhance low
and mid-range torque
OPERATION
The intake manifold delivers air to the combustion
chambers. This air allows the fuel delivered by the
fuel injectors to ignite when the spark plug fire.
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKS
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
Fig. 87 Oil Pump Sealing - Typical
1 - O-RING
2 - SEALER LOCATION
Fig. 88 Front Crankshaft Seal - Installation
1 - PROTECTOR
2 - SEAL
3 - SPECIAL TOOL 6780
Fig. 89 Crankshaft Sprocket - Installation
1 - SPECIAL TOOL 6792
2 - TIGHTEN NUT TO INSTALL
KJENGINE9s-51
OIL PUMP (Continued)

(2) Spray a small stream of water (Spray Bottle) at
the suspected leak area.
(3) If engine RPM'S change, the area of the sus-
pected leak has been found.
(4) Repair as required.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Disconnect connector from inlet air tempera-
ture sensor.
(3) Disconnect air intake tube at throttle body and
remove upper air cleaner housing.
(4) Disconnect connector from throttle position
sensor (TPS).
(5) Disconnect connector from idle air control (IAC)
motor.
(6) Disconnect connector from MAP sensor.
(7) Remove vacuum lines for purge solenoid and
PCV valve at intake manifold.
(8) Remove vacuum lines for power brake booster,
LDP, EGR transducer, and speed control vacuum res-
ervoir (if equipped) at intake manifold fittings.
(9) Disconnect throttle, speed control (if equipped),
and transaxle control (if equipped) and cables from
throttle lever and bracket. (Refer to 14 - FUEL SYS-
TEM/FUEL INJECTION/THROTTLE CONTROL
CABLE - REMOVAL)
(10) Perform fuel system pressure release proce-
durebefore attempting any repairs.(Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY - STANDARD
PROCEDURE)
(11) Disconnect fuel line. (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE)
(12) Disconnect coolant temperature sensor/fuel
injector wire harness connector.
(13) Disconnect fuel injector harness.
(14) Remove intake manifold to cylinder head fas-
teners.
(15) Remove the manifold from engine.
CAUTION: Cover intake manifold openings to pre-
vent foreign material from entering engine.
(16) Inspect the manifold. (Refer to 9 - ENGINE/
MANIFOLDS/INTAKE MANIFOLD - INSPECTION)
INSPECTION
(1) Check manifold surfaces for flatness with
straight edge. Surface must be flat within 0.15 mm
per 300 mm (0.006 in. per foot) of manifold length.
(2) Inspect manifold for cracks or distortion.
Replace manifold if necessary.
INSTALLATION
(1) Clean manifold sealing surfaces.
(2) Install new manifold to cylinder head seals.
(3) Install manifold to head.
(4) Install and tighten intake manifold fasteners to
28 N´m (250 in. lbs.) in the sequence shown (Fig. 90).
Repeat procedure until all bolts are at specified
torque.
(5) Install throttle cables in bracket.
(6) Connect throttle, speed control, (if equipped),
cables to throttle lever.
(7) Connect vacuum lines for power brake booster,
LDP, EGR transducer, and speed control vacuum res-
ervoir (if equipped) at upper intake manifold fittings.
(8) Connect vacuum lines for purge solenoid and
PCV valve.
(9) Connect electrical connectors for MAP sensor,
throttle position sensor (TPS), and idle air control
(IAC) motor.
(10) Connect the fuel line. (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE)
(11) Connect coolant temperature sensor/fuel injec-
tor wiring harness electrical connector.
(12) Install the air cleaner housing and air intake
tube to throttle body.
(13) Connect inlet air temperature sensor connec-
tor.
(14) Connect negative cable to battery.
Fig. 90 LOWER INTAKE MANIFOLD TIGHTENING
SEQUENCE
9s - 52 ENGINEKJ
INTAKE MANIFOLD (Continued)

EXHAUST MANIFOLD
DESCRIPTION
The exhaust manifold is made of Hi-Silicone Moly
nodular cast iron for strength and high tempera-
tures. The manifold attaches to the cylinder head.
OPERATION
The exhaust manifold collects the exhaust gasses
exiting the combustion chambers. Then it channels
the exhaust gasses to the exhaust pipe attached to
the manifold.
REMOVAL
(1) Raise vehicle and disconnect exhaust pipe from
the exhaust manifold.
(2) Lower the vehicle.
(3) Disconnect upstream oxygen sensor connector
at the rear of exhaust manifold.
(4) Remove the air cleaner bracket (Fig. 91).
(5) Remove the heat shield.
(6) Remove the bolts attaching the manifold to the
cylinder head.
(7) Remove exhaust manifold.
(8) Inspect the manifold. (Refer to 9 - ENGINE/
MANIFOLDS/EXHAUST MANIFOLD - INSPEC-
TION)
CLEANING
(1) Discard gasket (if equipped) and clean all sur-
faces of manifold and cylinder head.
INSPECTION
(1) Inspect manifold gasket surfaces for flatness
with straight edge. Surface must be flat within 0.15
mm per 300 mm (0.006 in. per foot) of manifold
length.
(2) Inspect manifolds for cracks or distortion.
Replace manifold as necessary.
INSTALLATION
(1) Clean the manifold mating surfaces.
(2) Install exhaust manifold with a new gasket.
Tighten attaching nuts to 20 N´m (175 in. lbs.).
(3) Attach exhaust pipe to exhaust manifold and
tighten fasteners to 37 N´m (27 ft. lbs.).
(4) Install and connect the oxygen sensor. (Refer to
14 - FUEL SYSTEM/FUEL INJECTION/O2 SENSOR
- COMPONENT LOCATION)
(5) Install the heat shield.
(6) Install the air cleaner bracket.
TIMING BELT COVER(S)
REMOVAL
FRONT COVER
(1) Remove crankshaft vibration damper. (Refer to
9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL)
(2) Remove generator drive belt tensioner assem-
bly. (Refer to 7 - COOLING/ACCESSORY DRIVE/
BELT TENSIONERS - REMOVAL)
(3) Remove timing belt front cover bolts, and
remove covers.
REAR COVER
(1) Remove front covers.
(2) Remove timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - REMOVAL)
(3) Hold camshaft sprocket with Special Tool 6847
while removing center bolt.
(4) Remove timing belt idler pulley.
(5) Remove rear cover fasteners and remove cover
from engine.
INSTALLATION
REAR COVER
(1) Install timing belt rear cover and bolts (Fig.
92). Torque bolts to 12 N´m (105 in. lbs).
Fig. 91 AIR CLEANER BRACKET
1 - AIR CLEANER BRACKET
2 - BOLT (2)
KJENGINE9s-53

CAUTION: Do not use an impact wrench for tighten-
ing camshaft sprocket bolt. Damage to the timing
locating pin can occur. Hand tighten using a
wrench ONLY.
(2) Install camshaft sprockets, and camshaft target
ring. Hold sprockets with Special Tool 6848 and
tighten center bolt to 101 N´m (75 ft. lbs.).
(3) Install timing belt idler pulley and tighten
mounting bolt to 61 N´m (45 ft. lbs.).
(4) Install timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKETS - INSTALLATION)
(5) Install accessory drive bracket (Fig. 93).
(6) Install front covers.
FRONT COVER
(1) Install timing belt front covers (Fig. 94).
Tighten fasteners to 7 N´m (60 in. lbs.).
(2) Install generator drive belt tensioner. (Refer to
7 - COOLING/ACCESSORY DRIVE/BELT TEN-
SIONERS - INSTALLATION)
(3) Install crankshaft vibration damper. (Refer to 9
- ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION)
Fig. 92 TIMING BELT REAR COVER FASTENERS
1 - OUTER COVER TO REAR COVER FASTENERS (3)
2 - REAR COVER TO CYLINDER HEAD FASTENERS
3 - OUTER COVER TO REAR COVER FASTENERS (3)
4 - INNER COVER TO BLOCK FASTENERS
Fig. 93 ACCESSORY DRIVE BRACKET
1- UPPER TIMING BELT COVER
2- LOWER TIMING BELT COVER
3- BELT TENSIONER
4- ACCESSORY DRIVE BRACKET
Fig. 94 TIMING BELT COVERS
1- UPPER TIMING BELT COVER
2- REAR TIMING BELT COVER
3- LOWER TIMING BELT COVER
4- ACCESSORY DRIVE BRACKET NOT SHOWN
9s - 54 ENGINEKJ
TIMING BELT COVER(S) (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