2002 JEEP LIBERTY oil

ENGINE
TABLE OF CONTENTS
page page
COOLANT RECOVERY PRESS CONTAINER
DESCRIPTION.........................19
OPERATION...........................19
ENGINE COOLANT TEMPERATURE SENSOR
DESCRIPTION.........................19
OPERATION...........................20
REMOVAL.............................20
INSTALLATION.........................21
ENGINE COOLANT THERMOSTAT
DESCRIPTION - 3.7L ENGINE.............21
OPERATION...........................21
DIAGNOSIS AND TESTING - THERMOSTAT . . . 21
REMOVAL - 3.7L ENGINE.................21
INSTALLATION - 3.7L ENGINE.............22
RADIATOR
DESCRIPTION.........................22
REMOVAL.............................23
CLEANING............................24
INSPECTION..........................24
INSTALLATION.........................24
RADIATOR PRESSURE CAP
DESCRIPTION.........................25
OPERATION...........................25
DIAGNOSIS AND TESTING - RADIATOR
PRESSURE CAP......................25CLEANING............................25
INSPECTION..........................25
RADIATOR FAN - ELECTRIC
DESCRIPTION.........................26
OPERATION...........................26
REMOVAL.............................26
INSTALLATION.........................27
RADIATOR - FAN - VISCOUS
DESCRIPTION.........................27
OPERATION...........................27
DIAGNOSIS AND TESTING - VISCOUS FAN
DRIVE..............................28
REMOVAL.............................28
CLEANING............................29
INSPECTION..........................29
INSTALLATION.........................29
WATER PUMP
DESCRIPTION
DESCRIPTION - WATER PUMP...........29
DESCRIPTION........................29
OPERATION - WATER PUMP..............30
REMOVAL.............................30
CLEANING............................31
INSPECTION..........................31
INSTALLATION.........................31
COOLANT RECOVERY PRESS
CONTAINER
DESCRIPTION
This system works along with the radiator pres-
sure cap. This is done by using thermal expansion
and contraction of the coolant to keep the coolant
free of trapped air. It provides:
²A volume for coolant expansion and contraction.
²A convenient and safe method for checking/ad-
justing coolant level at atmospheric pressure. This is
done without removing the radiator pressure cap.
²Some reserve coolant to the radiator to cover
minor leaks and evaporation or boiling losses.
As the engine cools, a vacuum is formed in the
cooling system of both the radiator and engine. Cool-
ant will then be drawn from the coolant tank and
returned to a proper level in the radiator.
The coolant reservoir/overflow system has a radia-
tor mounted pressurized cap, an overflow tube, and a
plastic coolant reservoir/overflow tank, mounted to
the right side of the cowl. It is mounted to the cowlwith two nuts on top, and a slide bracket on the bot-
tom.
OPERATION
The pressure chamber keeps the coolant free of
trapped air, provides a volume for expansion and con-
traction, and provides a convenient and safe method
for checking and adjusting coolant level at atmo-
spheric pressure. It also provides some reserve cool-
ant to cover minor leaks, evaporation or boiling
losses. The overflow chamber allows coolant recovery
in case of an overheat.
ENGINE COOLANT
TEMPERATURE SENSOR
DESCRIPTION
The Engine Coolant Temperature (ECT) sensor is
used to sense engine coolant temperature. The sensor
protrudes into an engine water jacket.
KJENGINE 7 - 19

RADIATOR PRESSURE CAP
DESCRIPTION
The cooling system cap is located on the coolant
pressure bottle. The cap construction includes; stain-
less steel swivel top, rubber seals and retainer, main
spring, and a spring loaded valve (Fig. 10).
OPERATION
The pressure cap allows the cooling system to oper-
ate at higher than atmospheric pressure which raises
the coolant boiling point, thus allowing increased
radiator cooling capacity. The pressure cap releases
pressure at some point within a range of 110 kPa  
14 kPa (16 psi   2 psi).
A spring-loaded vent valve in the center of the cap
allows the system to pressurize and depressurize
without creating a vacuum. If the valve is stuck
open, coolant will escape to the overflow hose. There
is also a gasket in the cap to seal to the top of the
filler neck.
CAUTION: Use only the pressure cap specified for
this vehicle. Use of other pressure caps can lead to
coolant loss and overheating.
DIAGNOSIS AND TESTING - RADIATOR
PRESSURE CAP
Remove cap from radiator. Be sure that sealing
surfaces are clean. Moisten rubber gasket with water
and install the cap on pressure tester (tool 7700 or
an equivalent) (Fig. 11).Operate the tester pump and observe the gauge
pointer at its highest point. The cap release pressure
should be 124 to 145 kPa (18 to 21 psi). The cap is
satisfactory when the pressure holds steady. It is also
good if it holds pressure within the 124 to 145 kPa
(18 to 21 psi) range for 30 seconds or more. If the
pointer drops quickly, replace the cap.
CAUTION: Radiator pressure testing tools are very
sensitive to small air leaks, which will not cause
cooling system problems. A pressure cap that does
not have a history of coolant loss should not be
replaced just because it leaks slowly when tested
with this tool. Add water to tool. Turn tool upside
down and recheck pressure cap to confirm that cap
needs replacement.
CLEANING
Clean the radiator pressure cap using a mild soap
and water only.
INSPECTION
Visually inspect the pressure valve gasket on the
cap. Replace cap if the gasket is swollen, torn or
worn. Inspect the area around radiator filler neck for
white deposits that indicate a leaking cap.
Fig. 10 PRESSURE CAP
1 - MAIN SPRING
2 - GASKET RETAINER
3 - STAINLESS STEEL SWIVEL TOP
4 - RUBBER SEALS
5 - SPRING LOADED VALVE
6 - COOLANT PRESSURE BOTTLE
7 - FILLER NECK
8 - OVERFLOW NIPPLEFig. 11 Pressure Testing Radiator Pressure Cap -
Typical
1 - PRESSURE CAP
2 - TYPICAL COOLING SYSTEM PRESSURE TESTER
KJENGINE 7 - 25

(5) Remove the two fan shroud mounting bolts con-
necting the fan shroud to the radiator (Fig. 14).
(6) Remove the shroud and fan from the vehicle.
INSTALLATION
NOTE: For 3.7L Heavy Duty/Max Cool/Trailer Tow
cooling package, the vicous fan cannot be installed
seperate from the shroud. Both fan and shroud
must be installed together.
(1) Gently lay vicous fan into shroud.
(2) Install fan shroud assembly into the vehicle.
Tighten fan shroud to radiator bolts to (5.5 N´m (50
in. lbs.).
(3) Using special tool 6958 spanner wrench and
8346 adapters, install the vicous fan on the water
pump.
(4) Connect fan motor wire connector to harness
connector, and attach connector to shroud.
(5) Connect battery negative cable.
(6) Start engine and check fan operation.
RADIATOR - FAN - VISCOUS
DESCRIPTION
CAUTION: If the viscous fan drive is replaced
because of mechanical damage, the cooling fan
blades should also be inspected. Inspect for fatigue
cracks, loose blades, or loose rivets that could
have resulted from excessive vibration. Replace fan
blade assembly if any of these conditions are
found. Also inspect water pump bearing and shaft
assembly for any related damage due to a viscous
fan drive malfunction.
The thermal viscous fan drive (Fig. 15) is a sili-
cone-fluid-filled coupling used to connect the fan
blades to the water pump shaft. The coupling allows
the fan to be driven in a normal manner. This is
done at low engine speeds while limiting the top
speed of the fan to a predetermined maximum level
at higher engine speeds.
On the 3.7L engine, an electric fan is standard and
the viscous fan is added on for trailer tow packages
only.
OPERATION
A thermostatic bimetallic spring coil is located on
the front face of the viscous fan drive unit. This
spring coil reacts to the temperature of the radiator
discharge air. It engages the viscous fan drive for
higher fan speed if the air temperature from the
radiator rises above a certain point. Until additional
engine cooling is necessary,the fan will remain at
a reduced rpm regardless of engine speed. Nor-
mally less than three hundred (300) rpm.
Fig. 14 Radiator Cooling Fan - Typical
1 - RADIATOR
2 - ELECTRIC COOLING FAN CONNECTOR
3 - FAN SHROUD
4 - ELECTRIC COOLING FAN
Fig. 15 Viscous Fan Drive - Typical
1 - VISCOUS FAN DRIVE
2 - THERMOSTATIC SPRING
3 - MOUNTING NUT TO WATER PUMP HUB
KJENGINE 7 - 27
RADIATOR FAN - ELECTRIC (Continued)

Only when sufficient heat is present, will the vis-
cous fan drive engage. This is when the air flowing
through the radiator core causes a reaction to the
bimetallic coil. It then increases fan speed to provide
the necessary additional engine cooling.
Once the engine has cooled, the radiator discharge
temperature will drop. The bimetallic coil again
reacts and the fan speed is reduced to the previous
disengaged speed.
DIAGNOSIS AND TESTING - VISCOUS FAN
DRIVE
If the fan assembly free-wheels without drag (the
fan blades will revolve more than five turns when
spun by hand), replace the fan drive. This spin test
must be performed when the engine is cool.
For the following test, the cooling system must be
in good condition. It also will ensure against exces-
sively high coolant temperature.
WARNING: BE SURE THAT THERE IS ADEQUATE
FAN BLADE CLEARANCE BEFORE DRILLING.
(1) Drill a 3.18-mm (1/8-in) diameter hole in the
top center of the fan shroud.
(2) Obtain a dial thermometer with an 8 inch stem
(or equivalent). It should have a range of -18É to
105ÉC (0É to 220É F). Insert thermometer through the
hole in the shroud. Be sure that there is adequate
clearance from the fan blades.
(3) Connect a tachometer and an engine ignition
timing light (timing light is to be used as a strobe
light).
(4) Block the air flow through the radiator. Secure
a sheet of plastic in front of the radiator (or air con-
ditioner condenser). Use tape at the top to secure the
plastic and be sure that the air flow is blocked.
(5) Be sure that the air conditioner (if equipped) is
turned off.
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 FAN. DO
NOT WEAR LOOSE CLOTHING.
(6) Start the engine and operate at 2400 rpm.
Within ten minutes the air temperature (indicated on
the dial thermometer) should be up to 93É C (200É F).
Fan driveengagementshould have started to occur
at between 91É to 96É C (195É to 205É F). Engage-
ment is distinguishable by a definiteincreasein fan
flow noise (roaring). The timing light also will indi-
cate an increase in the speed of the fan.
(7) When the air temperature reaches 93É C (200É
F), remove the plastic sheet. Fan drivedisengage-
mentshould have started to occur at between 62É to85É C (145É to 185É F). A definitedecreaseof fan
flow noise (roaring) should be noticed. If not, replace
the defective viscous fan drive unit.
REMOVAL
(1) Disconnect negative battery cable from battery.
NOTE: The thermal viscous fan drive/fan blade
assembly is attached (threaded) to water pump hub
shaft.
(2) Remove fan blade/viscous fan drive assembly
from water pump using special tool 6958 spanner
wrench and 8346 adapters, by turning mounting nut
counterclockwise as viewed from front (Fig. 16).
Threads on viscous fan drive areRIGHT HAND.
(3) Do not attempt to remove fan/viscous fan drive
assembly from vehicle at this time.
(4) Do not unbolt fan blade assembly from viscous
fan drive at this time.
(5) Remove fan shroud to radiator bolts.
(6) Remove fan shroud and fan blade/viscous fan
drive assembly as a complete unit from vehicle.
(7) After removing fan blade/viscous fan drive
assembly,do notplace viscous fan drive in horizon-
tal position. If stored horizontally, silicone fluid in
the viscous fan drive could drain into its bearing
assembly and contaminate lubricant.
Fig. 16 Viscous Fan and Fan Drive 3.7L
1 - SPECIAL TOOL 6958 SPANNER WRENCH WITH ADAPTER
PINS 8346
2-FAN
7 - 28 ENGINEKJ
RADIATOR - FAN - VISCOUS (Continued)

TRANSMISSION
TABLE OF CONTENTS
page
TRANS COOLER
DESCRIPTION.........................32
TRANS COOLER
DESCRIPTION
An internal high capacity/high efficiency cooler is
used on all vehicles, these coolers are an oil-to-cool-ant type, which consists of plates mounted in the
radiator outlet tank.Because the internal oil cooler is
so efficient, no auxiliary oil cooler is offered. The
cooler is not serviceable separately from the radiator.
7 - 32 TRANSMISSIONKJ

COOLING - 2.4L
TABLE OF CONTENTS
page page
COOLING - 2.4L
DESCRIPTION
DESCRIPTION - COOLING SYSTEM 2.4L
ENGINE..............................1
DESCRIPTION - HOSE CLAMPS...........1
OPERATION
OPERATION - COOLING SYSTEM.........2
OPERATION - HOSE CLAMPS............2
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ON-BOARD
DIAGNOSTICS (OBD)...................2
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS.............................2
DIAGNOSIS AND TESTING - COOLING
SYSTEM LEAKS.......................2
DIAGNOSIS AND TESTING - COOLING
SYSTEM DIAGNOSIS CHART.............5STANDARD PROCEDURE
STANDARD PROCEDURE - DRAINING
COOLING SYSTEM....................11
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM....................11
STANDARD PROCEDURE - COOLING
SYSTEM - REVERSE FLUSHING..........12
SPECIFICATIONS
TORQUE............................13
SPECIAL TOOLS
COOLING...........................13
ACCESSORY DRIVE......................14
ENGINE...............................18
TRANSMISSION.........................30
COOLING - 2.4L
DESCRIPTION
DESCRIPTION - COOLING SYSTEM 2.4L
ENGINE
The cooling system consists of the following items:
²Electric cooling fan - Standard.
²Radiator
²Hot bottle pressure cap
²Thermostat
²Coolant reserve/overflow system
²Radiator in-tank transmission oil cooler (if
equipped with an automatic transmission)
²Coolant
²Water pump
²Hoses and hose clamps
DESCRIPTION - HOSE CLAMPS
The cooling system utilizes spring type hose
clamps. If a spring type clamp replacement is neces-
sary, replace with the original Mopartequipment
spring type clamp.
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER6094) (Fig. 1). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS.
ALWAYS WEAR SAFETY GLASSES WHEN SERVIC-
ING CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps. If replacement
is necessary, use only a original equipment clamp
with matching number or letter (Fig. 1).
Fig. 1 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
KJCOOLING - 2.4L 7s - 1

The black light can be used in conjunction with a
pressure tester to determine if any external leaks
exist (Fig. 2).
PRESSURE TESTER METHOD
The engine should be at normal operating temper-
ature. Recheck the system cold if cause of coolant
loss is not located during the warm engine examina-
tion.
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING.
Carefully remove radiator pressure cap from pres-
sure bottle and check coolant level. Push down on
cap to disengage it from stop tabs. Wipe inside of
filler neck and examine lower inside sealing seat for
nicks, cracks, paint, and dirt. Inspect radiator-to-
reserve/overflow tank hose for internal obstructions.
Insert a wire through the hose to be sure it is not
obstructed.
Inspect cams on outside of filler neck. If cams are
damaged, seating of pressure cap valve and tester
seal will be affected.
Attach pressure tester (7700 or an equivalent) to
radiator filler neck (Fig. 3).
Operate tester pump to apply 110 kPa (16 psi)
pressure to system. If hoses enlarge excessively or
bulges while testing, replace as necessary. Observe
gauge pointer and determine condition of cooling sys-
tem according to following criteria:Holds Steady:If pointer remains steady for two
minutes, serious coolant leaks are not present in sys-
tem. However, there could be an internal leak that
does not appear with normal system test pressure. If
it is certain that coolant is being lost and leaks can-
not be detected, inspect for interior leakage or per-
form Internal Leakage Test.
Drops Slowly:Indicates a small leak or seepage
is occurring. Examine all connections for seepage or
slight leakage with a flashlight. Inspect radiator,
hoses, gasket edges and heater. Seal small leak holes
with a Sealer Lubricant (or equivalent). Repair leak
holes and inspect system again with pressure
applied.
Drops Quickly:Indicates that serious leakage is
occurring. Examine system for external leakage. If
leaks are not visible, inspect for internal leakage.
Large radiator leak holes should be repaired by a
reputable radiator repair shop.
INTERNAL LEAKAGE INSPECTION
Remove engine oil pan drain plug and drain a
small amount of engine oil. If coolant is present in
the pan, it will drain first because it is heavier than
oil. An alternative method is to operate engine for a
short period to churn the oil. After this is done,
remove engine dipstick and inspect for water glob-
ules. Also inspect transmission dipstick for water
globules and transmission fluid cooler for leakage.
Fig. 2 Leak Detection Using Black Light - Typical
1 - TYPICAL BLACK LIGHT TOOL
Fig. 3 Pressure Testing Cooling System - Typical
1 - TYPICAL COOLING SYSTEM PRESSURE TESTER
KJCOOLING - 2.4L7s-3
COOLING - 2.4L (Continued)

WARNING: WITH RADIATOR PRESSURE TESTER
TOOL INSTALLED ON RADIATOR, DO NOT ALLOW
PRESSURE TO EXCEED 124 KPA (18 PSI). PRES-
SURE WILL BUILD UP QUICKLY IF A COMBUSTION
LEAK IS PRESENT. TO RELEASE PRESSURE,
ROCK TESTER FROM SIDE TO SIDE. WHEN
REMOVING TESTER, DO NOT TURN TESTER MORE
THAN 1/2 TURN IF SYSTEM IS UNDER PRESSURE.
Operate engine without pressure cap on radiator
until thermostat opens. Attach a Pressure Tester to
filler neck. If pressure builds up quickly it indicates a
combustion leak exists. This is usually the result of a
cylinder head gasket leak or crack in engine. Repair
as necessary.
If there is not an immediate pressure increase,
pump the Pressure Tester. Do this until indicated
pressure is within system range of 110 kPa (16 psi).
Fluctuation of gauge pointer indicates compression or
combustion leakage into cooling system.
Because the vehicle is equipped with a catalytic
converter,do notremove spark plug cables or short
out cylinders to isolate compression leak.
If the needle on dial of pressure tester does not
fluctuate, race engine a few times to check for an
abnormal amount of coolant or steam. This would be
emitting from exhaust pipe. Coolant or steam from
exhaust pipe may indicate a faulty cylinder head gas-
ket, cracked engine cylinder block or cylinder head.
A convenient check for exhaust gas leakage into
cooling system is provided by a commercially avail-able Block Leak Check tool. Follow manufacturers
instructions when using this product.
COMBUSTION LEAKAGE TEST - WITHOUT
PRESSURE TESTER
DO NOT WASTE reusable coolant. If solution is
clean, drain coolant into a clean container for reuse.
WARNING: DO NOT REMOVE CYLINDER BLOCK
DRAIN PLUGS OR LOOSEN RADIATOR DRAIN-
COCK WITH SYSTEM HOT AND UNDER PRESSURE.
SERIOUS BURNS FROM COOLANT CAN OCCUR.
Drain sufficient coolant to allow thermostat
removal. (Refer to 7 - COOLING/ENGINE/ENGINE
COOLANT THERMOSTAT - REMOVAL). Remove
accessory drive belt (Refer to 7 - COOLING/ACCES-
SORY DRIVE/DRIVE BELTS - REMOVAL).
Add coolant to radiator to bring level to within 6.3
mm (1/4 in) of top of thermostat housing.
CAUTION: Avoid overheating. Do not operate
engine for an excessive period of time. Open drain-
cock immediately after test to eliminate boil over.
Start engine and accelerate rapidly three times, to
approximately 3000 rpm while observing coolant. If
internal engine combustion gases are leaking into
cooling system, bubbles will appear in coolant. If bub-
bles do not appear, internal combustion gas leakage
is not present.
7s - 4 COOLING - 2.4LKJ
COOLING - 2.4L (Continued)