2002 JEEP LIBERTY Crank sensor

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

NOTE: Plastigage is available in a variety of clear-
ance ranges. Use the most appropriate range for
the specifications you are checking.
(4) Install the proper crankshaft bearings to
achieve the specified bearing clearances. (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT MAIN
BEARINGS - STANDARD PROCEDURE) (Refer to 9
- ENGINE/ENGINE BLOCK/CONNECTING ROD
BEARINGS - STANDARD PROCEDURE)
REMOVAL - ENGINE ASSEMBLY
(1) Disconnect the battery negative cable.
(2) Remove hood. Mark hood hinge location for
reinstallation.
(3) Remove air cleaner assembly.
(4) Remove radiator core support bracket.
(5) Remove fan shroud with electric fan assembly.
(6) Remove drive belt.
NOTE: It is NOT necessary to discharge the A/C
system to remove the engine.
(7) Remove A/C compressor and secure away from
engine with lines attached.
(8) Remove generator and secure away from
engine.
NOTE: Do NOT remove the phenolic pulley from the
P/S pump. It is not required for P/S pump removal.
(9) Remove power steering pump with lines
attached and secure away from engine.
(10) Drain cooling system.
(11) Remove coolant bottle.
(12) Disconnect the heater hoses from the engine.
(13) Disconnect heater hoses from heater core and
remove hose assembly.
(14) Disconnect throttle and speed control cables.
(15) Remove upper radiator hose from engine.
(16) Remove lower radiator hose from engine.
(17) Disconnect the engine to body ground straps
at the left side of cowl.
(18) Disconnect the engine wiring harness at the
following points:
²Intake air temperature (IAT) sensor
²Fuel Injectors
²Throttle Position (TPS) Switch
²Idle Air Control (IAC) Motor
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold Absolute Pressure MAP) Sensor
²Camshaft Position (CMP) Sensor
²Coil Over Plugs
²Crankshaft Position Sensor
(19) Remove coil over plugs.
(20) Release fuel rail pressure.(21) Remove fuel rail and secure away from
engine.
(22) Remove the PCV hose.
(23) Remove the breather hoses.
(24) Remove the vacuum hose for the power brake
booster.
(25) Disconnect knock sensors.
(26) Secure the left and right engine wiring har-
nesses away from engine.
(27) Raise vehicle.
(28) Disconnect oxygen sensor wiring.
(29) Disconnect crankshaft postion sensor.
(30) Disconnect the engine block heater power
cable, if equipped.
(31) Disconnect the front propshaft at the front
differential and secure out of way.
(32) Remove the starter.
(33) Remove the ground straps from the engine
(34) Disconnect the exhaust pipes at the manifold.
(35) Remove the structural cover, if equipped.
(36) Remove torque convertor bolts, and mark
location for reassembly.
(37) Remove transmission bellhousing to engine
bolts.
(38) Loosen left and right engine mount thru bolts.
NOTE: It is not necessary to completely remove
engine mount thru bolts, for engine removal.
(39) Lower the vehicle.
(40) Support the transmission with a suitable jack.
(41) Connect a suitable engine hoist to the engine.
CAUTION: The 2.4L engine with manual transmis-
sions, can be removed without removing the man-
ual transmission. Use caution when attempting this
procedure as the clearance is tight.
(42) Remove engine from vehicle.
INSTALLATION - ENGINE ASSEMBLY
(1) Position the engine in the vehicle.
CAUTION: Use caution when installing 2.4L engine
into vehicle equipped with manual transmission, as
clearance is tight.
(2) Install both left and right side engine mounts
into the frame mounts.
(3) Raise the vehicle.
(4) Install the transmission bellhousing to engine
mounting bolts. Tighten the bolts to 41 N´m (30ft.
lbs.).
(5) Tighten the engine mount thru bolts.
(6) Install the torque convertor bolts.
(7) Connect the ground straps on the left and right
side of the engine.
9s - 12 ENGINEKJ
ENGINE - 2.4L (Continued)

(8) Install the starter.
(9) Connect the crankshaft position sensor.
(10) Install the engine block heater power cable, if
equipped.
CAUTION: The structural cover requires a specific
torque sequence. Failure to follow this sequence
may cause severe damage to the cover.
(11) Install the structural cover.
(12) Install the exhaust pipe.
(13) Connect the oxygen sensors.
(14) Lower vehicle.
(15) Connect the knock sensors.
(16) Connect the engine to body ground straps.
(17) Install the power brake booster vacuum hose.
(18) Install the breather hoses.
(19) Install the PCV hose.
(20) Install the fuel rail.
(21) Install the coil over plugs.
(22) Reconnect the engine wiring harness at the
following points:
²Intake air temperature (IAT) sensor
²Fuel Injectors
²Throttle Position (TPS) Switch
²Idle Air Control (IAC) Motor
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold Absolute Pressure MAP) Sensor
²Camshaft Position (CMP) Sensor
²Coil Over Plugs
²Crankshaft Position Sensor
(23) Connect lower radiator hose.
(24) Connect upper radiator hose.
(25) Connect throttle and speed control cables.
(26) Install the heater hose assembly.
(27) Install coolant recovery bottle.
(28) Install the power steering pump.
(29) Install the generator.
(30) Install the A/C compressor.
(31) Install the drive belt.
(32) Install the fan shroud with the electric fan
assembly.
(33) Install the radiator core support bracket.
(34) Install the air cleaner assembly.
(35) Refill the engine cooling system.
(36) Install the hood.
(37) Check and fill engine oil.
(38) Connect the battery negative cable.
(39) Start the engine and check for leaks.SPECIFICATIONS
SPECIFICATIONS - 2.4L ENGINE
DESCRIPTION SPECIFICATION
General Specification
Type In-Line OHV, DOHC
Number of Cylinders 4
Displacement 2.4 Liters
(148 cu. in.)
Bore 87.5 mm
(3.445 in.)
Stroke 101.0 mm
(3.976 in.)
Compression Ratio 9.4:1
Firing Order 1-3-4-2
Compression Pressure 690 kPa (Minimum)
(100 psi Minimum)
Max. Variation Between
Cylinders25%
Cylinder Block
Cylinder Bore Diameter 87.4924±87.5076 mm
(3.4446±3.4452 in.)
Out-of-Round (Max.) 0.051 mm
(0.002 in.)
Taper (Max.) 0.051 mm
(0.002 in.)
Pistons
Piston Diameter 87.463±87.481 mm
(3.4434±3.4441 in.)
Clearance @ 14 mm
(9/16 in.) from bottom of
skirt0.024±0.057 mm
(0.0009±0.0022 in.)
Weight 346±356 grams
(12.20±12.56 oz.)
Land Clearance
(Diametrical)0.614±0.664 mm
(0.024±0.026 in.)
Piston Length 66.25 mm
(2.608 in.)
Piston Ring Groove
Depth No. 14.640±4.784 mm
(0.182±0.188 in.)
Piston Ring Groove
Depth No. 24.575±4.719 mm
(0.180±0.185 in.)
KJENGINE9s-13
ENGINE - 2.4L (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)

LUBRICATION
DESCRIPTION
The lubrication system is a full-flow filtration,
pressure feed type. The oil pump is mounted in the
front engine cover and driven by the crankshaft.
OPERATION
Engine oil drawn up through the pickup tube and
is pressurized by the oil pump and routed through
the full-flow filter to the main oil gallery running the
length of the cylinder block. A diagonal hole in each
bulkhead feeds oil to each main bearing. Drilled pas-
sages within the crankshaft route oil from main bear-
ing journals to connecting rod journals. Balance shaft
lubrication is provided through an oil passage from
the number one main bearing cap through the bal-
ance shaft carrier support leg. This passage directly
supplies oil to the front bearings and internal
machined passages in the shafts that routes oil from
front to the rear shaft bearing journals. A vertical
hole at the number five bulkhead routes pressurized
oil through a restrictor (integral to the cylinder head
gasket) up past a cylinder head bolt to an oil gallery
running the length of the cylinder head. The cam-
shaft journals are partially slotted to allow a prede-
termined amount of pressurized oil to pass into the
bearing cap cavities. Lubrication of the camshaft
lobes are provided by small holes in the camshaft
bearing caps that are directed towards each lobe. Oil
returning to the pan from pressurized components
supplies lubrication to the valve stems. Cylinder
bores and wrist pins are splash lubricated from
directed slots on the connecting rod thrust collars.
DIAGNOSIS AND TESTING - ENGINE OIL
PRESSURE CHECKING
(1) Disconnect and remove oil pressure switch.
(Refer to 9 - ENGINE/LUBRICATION/OIL PRES-
SURE SENSOR/SWITCH - REMOVAL)
(2) Install Special Tools C-3292 Gauge with 8406
Adaptor fitting.
(3) Start engine and record oil pressure. Refer to
Specifications for correct oil pressure requirements.
(Refer to 9 - ENGINE - SPECIFICATIONS)
CAUTION: If oil pressure is 0 at idle, do not perform
the 3000 RPM test
(4) If oil pressure is 0 at idle. Shut off engine,
check for pressure relief valve stuck open, a clogged
oil pick-up screen or a damaged oil pick-up tube
O-ring.
(5) After test is complete, remove test gauge and
fitting.
Fig. 76 TRANSMISSION MOUNT 3.7L 2WD AUTO
TRANS
1 - BOLT
2 - MOUNT
Fig. 77 TRANSMISSION MOUNT 3.7L 4WD AUTO
TRANS
1 - MOUNT
2 - BOLT
9s - 46 ENGINEKJ
LUBRICATION (Continued)

(6) Install oil pressure switch and connector. (Refer
to 9 - ENGINE/LUBRICATION/OIL PRESSURE
SENSOR/SWITCH - INSTALLATION)
OIL
STANDARD PROCEDURE
ENGINE OIL LEVEL CHECK
The best time to check engine oil level is after it
has sat overnight, or if the engine has been running,
allow the engine to be shut off for at least 5 minutes
before checking oil level.
Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil level
reading. Remove dipstick and observe oil level. Add
oil only when the level is at or below the ADD mark
(Fig. 78).
STANDARD PROCEDURE - ENGINE OIL AND
FILTER CHANGE
Change engine oil at mileage and time intervals
described in the Maintenance Schedule. (Refer to
LUBRICATION & MAINTENANCE/MAINTE-
NANCE SCHEDULES - DESCRIPTION)
WARNING: NEW OR USED ENGINE OIL CAN BE
IRRITATING TO THE SKIN. AVOID PROLONGED OR
REPEATED SKIN CONTACT WITH ENGINE OIL.
CONTAMINANTS IN USED ENGINE OIL, CAUSED BY
INTERNAL COMBUSTION, CAN BE HAZARDOUS TO
YOUR HEALTH. THOROUGHLY WASH EXPOSED
SKIN WITH SOAP AND WATER. DO NOT WASH
SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR
SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO
NOT POLLUTE, DISPOSE OF USED ENGINE OIL
PROPERLY. CONTACT YOUR DEALER OR GOVERN-
MENT AGENCY FOR LOCATION OF COLLECTION
CENTER IN YOUR AREA.
Run engine until achieving normal operating tem-
perature.
(1) Position the vehicle on a level surface and turn
engine off.(2) Hoist and support vehicle on safety stands.
Refer to Hoisting and Jacking Recommendations.
(Refer to LUBRICATION & MAINTENANCE/HOIST-
ING - STANDARD PROCEDURE)
(3) Remove oil fill cap.
(4) Place a suitable drain pan under crankcase
drain.
(5) Remove drain plug from crankcase and allow
oil to drain into pan. Inspect drain plug threads for
stretching or other damage. Replace drain plug and
gasket if damaged.
(6) Remove oil filter. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL FILTER - REMOVAL)
(7) Install and tighten drain plug in crankcase.
(8) Install new oil filter. (Refer to 9 - ENGINE/LU-
BRICATION/OIL FILTER - INSTALLATION)
(9) Lower vehicle and fill crankcase with specified
type and amount of engine oil. (Refer to LUBRICA-
TION & MAINTENANCE/FLUID TYPES -
DESCRIPTION)
(10) Install oil fill cap.
(11) Start engine and inspect for leaks.
(12) Stop engine and inspect oil level.
NOTE: Care should be exercised when disposing
used engine oil after it has been drained from a
vehicle engine. Refer to the WARNING listed above.
OIL FILTER
DESCRIPTION
The engine oil filter is a high quality full-flow, dis-
posable type. Replace the oil filter with a Mopartor
the equivalent.
REMOVAL
(1) Raise vehicle on hoist.
(2) Position an oil collecting container under oil fil-
ter location.
CAUTION: When servicing the oil filter avoid
deforming the filter can by installing the remove/in-
stall tool band strap against the can to base lock
seam. The lock seam joining the can to the base is
reinforced by the base plate.
(3) Using a suitable filter wrench, turn oil filter
counterclockwise to remove (Fig. 79).
INSTALLATION
(1) Clean and check filter mounting surface. The
surface must be smooth, flat and free of debris or
pieces of gasket.
(2) Lubricate new oil filter gasket with clean
engine oil.
Fig. 78 Oil Level
1 - ENGINE OIL LEVEL DIPSTICK
KJENGINE9s-47
LUBRICATION (Continued)

(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)