2002 JEEP LIBERTY Engine

(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)

DESCRIPTION SPECIFICATION
Piston Ring Groove
Depth No. 34.097±4.236 mm
(0.161±0.166 in.)
Piston Pins
Clearance in Piston 0.005±0.018 mm
(0.0002±0.0008 in.)
Clearance in Connecting
RodInterference
Diameter 21.998±22.003 mm
(0.8660±0.8662 in.)
End Play None
Length 72.75±73.25 mm
(2.864±2.883 in.)
Piston Rings
Ring GapÐTop
Compression Ring0.25±0.51 mm
(0.0098±0.020 in.)
Wear Limit 0.8 mm
(0.031 in.)
Ring GapÐ2nd
Compression Ring0.23±0.48 mm
(0.009±0.018 in.)
Wear Limit 0.8 mm
(0.031 in.)
Ring GapÐOil Control
Steel Rails0.25±0.64 mm
(0.0098±0.025 in.)
Wear Limit 1.00 mm
(0.039 in.)
Ring Side ClearanceÐ
Compression Rings0.030±0.080 mm
(0.0011±0.0031 in.)
Wear Limit 0.10 mm
(0.004 in.)
Ring Side ClearanceÐOil
Ring Pack0.012±0.178 mm
(0.0004±0.0070 in.)
Ring WidthÐ
Compression Rings1.47±1.50 mm
(0.057±0.059 in.)
Ring WidthÐOil Ring
Pack2.72±2.88 mm
(0.107±0.1133 in.)
Connecting Rod
Bearing Clearance 0.025±0.071 mm
(0.0009±0.0027 in.)
Wear Limit 0.075 mm
(0.003 in.)
Bore DiameterÐPiston
Pin20.96±20.98 mm
(0.8252±0.8260 in.)DESCRIPTION SPECIFICATION
Bore DiameterÐ
Crankshaft End53.007±52.993 mm
(2.0868±2.0863 in.)
Side Clearance 0.13±0.38 mm
(0.005±0.015 in.)
Wear Limit 0.40 mm
(0.016 in.)
WeightÐTotal (Less
Bearing)565.8 grams
(19.96 oz.)
Crankshaft
Connecting Rod Journal
Diameter49.984±50.000 mm
(1.968±1.9685 in.)
Main Bearing Journal
Diameter59.992±60.008 mm
(2.362±2.3625 in.)
Journal Out-of-Round
(Max.)0.0035 mm
(0.0003 in.)
Journal Taper (Max.) 0.007 mm
(0.0001 in.)
End Play 0.09±0.24 mm
(0.0035±0.0094 in.)
Wear Limit 0.38 mm
(0.015 in.)
Main Bearing Diametrical
Clearance0.018±0.062 mm
(0.0007±0.0024 in.)
Hydraulic Lash Adjuster
Body Diameter 15.901±15.913 mm
(0.626±0.6264 in.)
Plunger Travel Minimum
(Dry)3.0 mm
(0.118 in.)
Cylinder Head Camshaft Bearing Bore Diameter
Journals No.1±6 26.020±26.041 mm
(1.024±1.025 in.)
Camshaft
Journal Diameter No. 1±6 25.951±25.970 mm
(1.021±1.022 in.)
Bearing ClearanceÐ
Diametrical0.069±0.071 mm
(0.0027±0.003 in.)
End Play 0.05±0.17 mm
(0.0019±0.0066 in.)
Lift (Zero Lash)
Intake 8.25 mm
(0.324 in.)
9s - 14 ENGINEKJ
ENGINE - 2.4L (Continued)

DESCRIPTION SPECIFICATION
Exhaust 6.60 mm
(0.259 t>
Intake Valve Timing*
Closes (ABDC) 51É
Opens (BTDC) 1É
Duration 232É
Exhaust Valve Timing*
Closes (ATDC) 7É
Opens (BBDC) 47É
Duration 234É
Valve Overlap 8É
*All readings in crankshaft degrees. Timing points @
4É from top of Ramps.
Cylinder Head
Material Cast Aluminum
Gasket Thickness
(Compressed)0.71 mm
(0.028 in.)
Valve Seat
Angle 44.5±45É
Seat DiameterÐIntake 34.37±34.63 mm
(1.353±1.363 in.)
Seat DiameterÐExhaust 27.06±27.32 mm
(1.065±1.075 in.)
Runout (Max.) 0.05 mm
(0.002 in.)
Valve Seat WidthÐIntake
and Exhaust0.9±1.3 mm
(0.035±0.051 in.)
Service LimitÐIntake 2.0 mm
(0.079 in.)
Service LimitÐExhaust 2.5 mm
(0.098 in.)
Valve Guide
Diameter I.D. 5.975±6.000 mm
(0.235±0.236 in.)
Guide Bore Diameter 11.0±11.02 mm
(0.4330±0.4338 in.)
Guide Height (spring seat
to guide tip)13.25±13.75 mm
(0.521±0.541 in.)
Valves
Face AngleÐIntake and
Exhaust44.5Ð45ÉDESCRIPTION SPECIFICATION
Head DiameterÐIntake 34.67±34.93 mm
1.364±1.375 in.)
Head DiameterÐExhaust 28.32±28.52 mm
(1.114±1.122 in.)
Valve Length (Overall)
ÐIntake 112.76±113.32 mm
(4.439±4.461 in.)
ÐExhaust 110.89±111.69 mm
(4.365±4.397 in.)
Valve Stem Diameter
ÐIntake 5.934±5.952 mm
(0.2337±0.2344 in.)
ÐExhaust 5.906±5.924 mm
(0.2326±0.2333 in.)
Valve Margin
Intake 1.2±1.7 mm
(0.047±0.066 in.)
Service Limit 0.95 mm
(1/32 in.)
Exhaust 0.985±1.315 mm
(0.038±0.051 in.)
Service Limit 1.05 mm
(3/64 in.)
Valve Stem Tip
Intake 48.04 mm
(1.891 in.)
Exhaust 47.99 mm
(1.889 in.)
Valve Stem to Guide Clearance
Intake 0.048±0.066 mm
(0.0018±0.0025 in.)
Max. Allowable 0.076 mm
(0.003 in.)
Service Limit 0.25 mm
(0.010 in.)
Exhaust 0.0736±0.094 mm
(0.0029±0.0037 in.)
Max. Allowable 0.101 mm
(0.004 in.)
Service Limit 0.25 mm
(0.010 in.)
KJENGINE9s-15
ENGINE - 2.4L (Continued)

DESCRIPTION SPECIFICATION
Valve Springs
Free Length (Approx.) 48.4 mm
(1.905 in.)
Nominal Force (Valve
Closed)338 N @ 38.0 mm
(75.98 lbs. @ 1.496 in.)
Nominal Force (Valve
Open)607 N @ 29.75 mm
(136 lbs. @ 1.172 in.)
Installed Height 38.00 mm
(1.496 in.)
Number of Coils 7.82
Wire Diameter 3.86 mm
(1.496 in.)
Oil Pump
Clearance Over Rotors
(Max.)0.10 mm
(0.004 in.)
Cover Out-of-Flat (Max.) 0.025 mm
(0.001 in.)
Inner Rotor Thickness
(Min.)9.40 mm
(0.370 in.)
Outer Rotor Thickness
(Min.)9.40 mm
(0.370 in.)
Outer Rotor Clearance
(Max.)0.039 mm
(0.015 in.)
Outer Rotor Diameter
(Min.)79.95 mm
(3.148 in.)
Tip Clearance Between
Rotors (Max.)0.20 mm
(0.008 in.)
Oil Pressure
At Curb Idle Speed* 25 kPa
(4 psi)
At 3000 rpm 170±550 kPa
(25±80 psi)
CAUTION:
*If pressure is ZERO at curb idle, DO NOT run engine
at 3000 rpm.SPECIFICATIONS - TORQUE
DESCRIPTION N´mFt.
Lbs.In.
Lbs.
Balance Shaft Carrier to
BlockÐBolts54 40 Ð
Balance Shaft Gear
CoverÐDouble Ended
Fastener12 Ð 105
Balance Shaft SprocketÐ
Bolt28 Ð 250
Balance Shaft Chain
TensionerÐBolts12 Ð 105
Balance Shaft Carrier
CoverÐBolts12 Ð 105
Camshaft SprocketÐBolt 101 75 Ð
Connecting Rod
CapÐBolts54 +
1¤4
turn40
+1¤4
turnÐ
Crankshaft Main Bearing
Cap/Bedplate
ÐM8 Bolts 34 250
ÐM11 Bolts 41 +
1¤4
Turn30
+1¤4
TurnÐ
Crankshaft Damper 136 100 Ð
Cylinder HeadÐBolts (Refer to 9 - ENGINE/
CYLINDER HEAD -
INSTALLATION)
Cylinder Head CoverÐ
Bolts12 Ð 105
Flex Plate to Crankshaft 95 70 Ð
Flywheel Mounting Bolts 81 60 Ð
Engine Mount Bracket
RightÐBolts61 45 Ð
Engine MountingÐBolts (Refer to 9 ENGINE/
ENGINE MOUNTING)
Exhaust Manifold to
Cylinder HeadÐBolts23 Ð 200
Exhaust Manifold Heat
ShieldÐBolts12 Ð 105
Intake Manifold - Lower
ÐBolts28 Ð 250
Oil Filter 20 15 Ð
Oil PanÐBolts 12 Ð 105
Oil Pan DrainÐPlug 27 20 Ð
Oil Pump to BlockÐBolts 28 Ð 250
9s - 16 ENGINEKJ
ENGINE - 2.4L (Continued)

DESCRIPTION N´mFt.
Lbs.In.
Lbs.
Oil Pump Cover
PlateÐBolts12 Ð 105
Oil Pump Pick-up
TubeÐBolt28 20 Ð
Oil Pump Relief
ValveÐCap41 30
Spark Plugs 28 Ð
Timing Belt Covers
- Front Covers to Rear
CoverÐBolts12 Ð 105
- Rear CoverÐBolts 12 Ð 105
Timing Belt Tensioner
AssemblyÐBolts61 45 Ð
SPECIAL TOOLS
2.4L ENGINE
Puller 1026
Crankshaft Damper Removal Insert 6827-A
Camshaft Sprocket Holder 6847
Camshaft Seal Remover C-4679-A
Camshaft Seal Installer MD-998306
Crankshaft Damper Installer 6792
Valve Spring Compressor 8215
Adaptor 8436
KJENGINE9s-17
ENGINE - 2.4L (Continued)

Valve Spring Compressor MD-998772-A
Valve Spring Compressor Adapter 6779
Cylinder Bore Gage C-119
Crankshaft Sprocket Remover 6793
Crankshaft Sprocket Remover Insert C-4685-C2
Crankshaft Seal Remover 6771
Oil Pressure Gage C-3292
Rear Crankshaft Seal Guide and Installer 6926-1 and
6926-2
Balance Shaft Sprocket Installer 6052
Front Crankshaft Oil Seal Installer 6780
9s - 18 ENGINEKJ
ENGINE - 2.4L (Continued)

AIR CLEANER ELEMENT
REMOVAL - 2.4L
Housing removal is not necessary for element (fil-
ter) replacement.
(1) Disconnect air intake duct at side of element
cover.
(2) Pry up 2 spring clips from front of housing
cover (spring clips retain cover to housing).
(3) Release housing cover from locating tabs
located on rear of housing, and remove cover.
(4) Remove air cleaner element (filter) from hous-
ing.
(5) Clean inside of housing before replacing ele-
ment.
INSTALLATION - 2.4L
(1) Install element into housing.
(2) Position housing cover into housing locating
tabs.
(3) Pry up spring clips and lock cover to housing.
(4) Connect air intake duct.
If any air filter, air resonator, air intake tubes or
air filter housing clamps had been loosened or
removed, tighten them to 5 N´m (40 in. lbs.) torque.
CYLINDER HEAD
DESCRIPTION
The cross flow designed, aluminum cylinder head
contains dual over-head camshafts with four valves
per cylinder (Fig. 5). The valves are arrange in two
in-line banks. The intake valves face toward the left
side of the vehicle. The exhaust valves face the right
side. The cylinder head incorporates powdered metalvalve guides and seats. The cylinder head is sealed to
the block using a multi-layer steel head gasket and
retaining bolts.
Integral oil galleries providing lubrication passages
to the hydraulic lash adjusters, camshafts, and valve
mechanisms.
OPERATION
The cylinder head closes the combustion chamber,
allowing the pistons to compress the fuel/air mixture
for ignition. The valves are actuated by the lobe pro-
files on the camshaft to open and close at specified
duration to either allow clean air in the combustion
chamber or the exhaust gases out; depending on the
stroke of the engine.
DIAGNOSIS AND TESTING - CYLINDER HEAD
GASKET
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
Combustion Leak Tester C-3685-A
Cylinder Compression Pressure Adaptor 8116
Fig. 5 Cylinder Head and Camshafts
CAM PLUG - NOT SHOWN
1 - CAMSHAFT BEARING CAPS
2 - PLUG
3 - CAMSHAFT
4 - CYLINDER HEAD
5 - CAMSHAFT OIL SEAL
KJENGINE9s-19
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)