2002 JEEP LIBERTY vent

(Mopar Radiator Kleen or equivalent) before flushing.
This will soften scale and other deposits and aid the
flushing operation.
CAUTION: Be sure instructions on the container are
followed.
REVERSE FLUSHING RADIATOR
Disconnect the radiator hoses from the radiator fit-
tings. Attach a section of radiator hose to the radia-
tor bottom outlet fitting and insert the flushing gun.
Connect a water supply hose and air supply hose to
the flushing gun.
CAUTION: The cooling system normally operates at
97-to-110 kPa (14- to-16 psi) pressure. Exceeding
this pressure may damage the radiator or hoses.
Allow the radiator to fill with water. When radiator
is filled, apply air in short blasts allowing radiator to
refill between blasts. Continue this reverse flushing
until clean water flows out through rear of radiator
cooling tube passages. For more information, refer to
operating instructions supplied with flushing equip-
ment. Have radiator cleaned more extensively by a
radiator repair shop.
REVERSE FLUSHING ENGINE
Drain the cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE). Remove the thermostat
housing and thermostat. Install the thermostat hous-
ing. Disconnect the radiator upper hose from the
radiator and attach the flushing gun to the hose. Dis-
connect the radiator lower hose from the water
pump. Attach a lead away hose to the water pump
inlet fitting.
CAUTION: Be sure that the heater control valve is
closed (heat off). This is done to prevent coolant
flow with scale and other deposits from entering
the heater core.
Connect the water supply hose and air supply hose
to the flushing gun. Allow the engine to fill with
water. When the engine is filled, apply air in short
blasts, allowing the system to fill between air blasts.
Continue until clean water flows through the lead
away hose. For more information, refer to operating
instructions supplied with flushing equipment.
Remove the lead away hose, flushing gun, water
supply hose and air supply hose. Remove the thermo-
stat housing (Refer to 7 - COOLING/ENGINE/EN-
GINE COOLANT THERMOSTAT - REMOVAL).
Install the thermostat and housing with a replace-
ment gasket (Refer to 7 - COOLING/ENGINE/EN-
GINE COOLANT THERMOSTAT -INSTALLATION). Connect the radiator hoses. Refill
the cooling system with the correct antifreeze/water
mixture (Refer to 7 - COOLING - STANDARD PRO-
CEDURE).
SPECIFICATIONS
TORQUE
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Automatic Belt Tensioner to
Mounting
BracketÐBolt
2.4L - Ð -
4.7L 41 30 Ð
Automatic Belt Tensioner
PulleyÐ
Bolt
(3.7L) 61 45 Ð
Block HeaterÐBolt
2.4L - Ð -
3.7L 2 Ð 17
Condenser to Radiator Bolts 8 70
Coolant Overflow Bottle to
Plenum mounting bolts - 2.4L
only8.5 75
Coolant Pressure Bottle to
Plenum mounting bolts -3.7L
only8.5 75
Electric Fan to Fan Shroud
bolts5.5 50
Fan Blade Assy. to Viscous
Drive
Bolts 3.7L 23 Ð 210
Fan Shroud to Radiator
Mounting Bolts8Ð70
Radiator Upper Isolator to
Crossmember - Bolts 9.5 Ð 85
Thermostat HousingÐBolts
2.4L - - Ð
4.7L 13 Ð 115
Water PumpÐBolts
2.4L Ð Ð Ð
4.7L 54 40 Ð
KJCOOLING 7 - 13
COOLING (Continued)

REMOVAL
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM COOLANT
CAN OCCUR. REFER TO COOLING SYSTEM DRAIN-
ING.
Do not waste reusable coolant. If the solution is
clean, drain the coolant into a clean container for
reuse.
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 (NUMBER
6094) (Fig. 6). 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 (Fig. 7). If
replacement is necessary, use only an original
equipment clamp with matching number or letter.
CAUTION: When removing the radiator or A/C con-
denser for any reason, note the location of all radi-
ator-to-body and radiator-to-A/C condenser rubber
air seals (Fig. 8). These are used at the top, bottom
and sides of the radiator and A/C condenser. To
prevent overheating, these seals must be installed
to their original positions.(1) Disconnect the negative battery cable at bat-
tery.
(2) Drain coolant from radiator (Refer to 7 -
COOLING - STANDARD PROCEDURE).
Fig. 6 Hose Clamp Tool - Typical
1 - HOSE CLAMP TOOL 6094
2 - HOSE CLAMP
Fig. 7 Clamp Number/Letter Location - Typical
1 - TYPICAL CONSTANT TENSION HOSE CLAMP
2 - CLAMP NUMBER/LETTER LOCATION
3 - TYPICAL HOSE
Fig. 8 Air Seals - Typical
1 - AIR DAM
2 - RADIATOR
3 - AIR DAM
4 - A/C CONDENSER
5 - AIR SEAL
KJENGINE 7 - 23
RADIATOR (Continued)

(3) Remove the front grill (Refer to 23 - BODY/EX-
TERIOR/GRILLE - REMOVAL).
(4) Remove the cooling fan from the engine, if
equipped.
(5) Remove the two radiator mounting bolts.
(6) Disconnect both transmission cooler lines from
radiator.
(7) Disconnect the connector for the electric fan.
(8) Disconnect the power steering cooler line from
cooler.
(9) Disconnect the radiator upper and lower hoses.
(10) Disconnect the overflow hose from radiator.
(11) The lower part of radiator is equipped with
two alignment dowel pins (Fig. 9). They are located
on the bottom of radiator tank and fit into rubber
grommets. These rubber grommets are pressed into
the radiator lower crossmember.
WARNING: THE AIR CONDITIONING SYSTEM (IF
EQUIPPED) IS UNDER A CONSTANT PRESSURE
EVEN WITH THE ENGINE OFF. REFER TO REFRIG-
ERANT WARNINGS IN, HEATING AND AIR CONDI-
TIONING BEFORE HANDLING ANY AIR
CONDITIONING COMPONENT.
NOTE: The radiator and radiator cooling fan can be
removed as an assembly. It is not necessary toremove the cooling fan before removing or install-
ing the radiator.
(12) Gently lift up and remove radiator from vehi-
cle. Be careful not to scrape the radiator fins against
any other component. Also be careful not to disturb
the air conditioning condenser (if equipped).
CLEANING
Clean radiator fins With the engine cold, apply cold
water and compressed air to the back (engine side) of
the radiator to flush the radiator and/or A/C con-
denser of debris.
INSPECTION
The radiator cooling fins should be checked for
damage or deterioration. Inspect cooling fins to make
sure they are not bent or crushed, these areas result
in reduced heat exchange causing the cooling system
to operate at higher temperatures. Inspect the plastic
end tanks for cracks, damage or leaks.
Inspect the radiator neck for damage or distortion.
INSTALLATION
CAUTION: Before installing the radiator or A/C con-
denser, be sure the radiator-to-body and radiator-to-
A/C condenser rubber air seals are properly
fastened to their original positions. These are used
at the top, bottom and sides of the radiator and A/C
condenser. To prevent overheating, these seals
must be installed to their original positions.
(1) Gently lower the radiator and fan shroud into
the vehicle. Guide the two radiator alignment dowels
into the rubber grommets located in lower radiator
crossmember.
(2) Connect the radiator upper and lower hoses
and hose clamps to radiator.
CAUTION: The tangs on the hose clamps must be
positioned straight down.
(3) Install coolant reserve/overflow tank hose at
radiator.
(4) Connect both transmission cooler lines at the
radiator.
(5) Install both radiator mounting bolts.
(6) Reconnect the electric cooling fan.
(7) Install the grill (Refer to 23 - BODY/EXTERI-
OR/GRILLE - INSTALLATION).
(8) Reinstall the cooling fan to the engine.
(9) Rotate the fan blades (by hand) and check for
interference at fan shroud.
(10) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(11) Connect battery cable at battery.
(12) Start and warm engine. Check for leaks.
Fig. 9 Radiator Alignment Dowels - Typical
1 - RADIATOR
2 - ALIGNMENT DOWEL
3 - RADIATOR LOWER ISOLATOR
4 - RADIATOR LOWER CROSSMEMBER
7 - 24 ENGINEKJ
RADIATOR (Continued)

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

CAUTION: Do not remove water pump pulley-to-wa-
ter pump bolts. This pulley is under belt tension.
(8) Remove four bolts securing fan blade assembly
to viscous fan drive.
CLEANING
Clean the fan blades using a mild soap and water.
Do not use an abrasive to clean the blades.
INSPECTION
WARNING: DO NOT ATTEMPT TO BEND OR
STRAIGHTEN FAN BLADES IF FAN IS NOT WITHIN
SPECIFICATIONS.
CAUTION: If fan blade assembly is replaced
because of mechanical damage, water pump and
viscous fan drive should also be inspected. These
components could have been damaged due to
excessive vibration.
(1) Remove fan blade assembly from viscous fan
drive unit (four bolts).
(2) Lay fan on a flat surface with leading edge fac-
ing down. With tip of blade touching flat surface,
replace fan if clearance between opposite blade and
surface is greater than 2.0 mm (.090 inch). Rocking
motion of opposite blades should not exceed 2.0 mm
(.090 inch). Test all blades in this manner.
(3) Inspect fan assembly for cracks, bends, loose
rivets or broken welds. Replace fan if any damage is
found.
INSTALLATION
(1) Assemble fan blade to viscous fan drive.
Tighten mounting bolts to 27 N´m (20 ft. lbs.) torque.
NOTE: The vicous fan and fan shroud must be
installed as an assembly.
(2) Gently lay vicous fan into fan shroud.
(3) Install the fan shroud to radiator mounting
bolts, torque bolts to (5.5N´M or 50 in´lbs).
(4) Thread the fan and fan drive onto the water
pump pulley, and tighten nut using special tool 6958
spanner wrench and 8346 adapters.
(5) Connect the electrical connector for the electric
fan.
CAUTION: When installing a serpentine accessory
drive belt, the belt MUST be routed correctly. If not,
the engine may overheat due to the water pump
rotating in the wrong direction. (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL)
for correct belt routing.
WATER PUMP
DESCRIPTION
DESCRIPTION - WATER PUMP
A centrifugal water pump circulates coolant
through the water jackets, passages, intake manifold,
radiator core, cooling system hoses and heater core.
The pump is driven from the engine crankshaft by a
single serpentine drive belt.
The water pump impeller is pressed onto the rear
of a shaft that rotates in bearings pressed into the
housing. The housing has two small holes to allow
seepage to escape. The water pump seals are lubri-
cated by the antifreeze in the coolant mixture. No
additional lubrication is necessary.
Both heater hoses are connected to fittings on the
timing chain front cover. The water pump is also
mounted directly to the timing chain cover and is
equipped with a non serviceable integral pulley (Fig.
17).
DESCRIPTION
The 3.7L engine uses an internal water/coolant
bypass system. The design uses galleries in the tim-
ing chain cover to circulate coolant during engine
warm-up preventing the coolant from flowing
Fig. 17 Water Pump and Timing Chain Cover
1 - INTEGRAL WATER PUMP PULLEY
2 - TIMING CHAIN COVER
3 - THERMOSTAT HOUSING
4 - HEATER HOSE FITTINGS
5 - WATER PUMP
KJENGINE 7 - 29
RADIATOR - FAN - VISCOUS (Continued)

OPERATION
OPERATION - COOLING SYSTEM
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
OPERATION - HOSE CLAMPS
The spring type hose clamp applies constant ten-
sion on a hose connection. To remove a spring type
hose clamp, only use constant tension clamp pliers
designed to compress the hose clamp.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ON-BOARD
DIAGNOSTICS (OBD)
COOLING SYSTEM RELATED DIAGNOSTICS
The powertrain control module (PCM) has been
programmed to monitor certain cooling system com-
ponents:
²If the engine has remained cool for too long a
period, such as with a stuck open thermostat, a Diag-
nostic Trouble Code (DTC) can be set.
²If an open or shorted condition has developed in
the relay circuit controlling the electric radiator fan,
a Diagnostic Trouble Code (DTC) can be set.
If the problem is sensed in a monitored circuit
often enough to indicated an actual problem, a DTC
is stored. The DTC will be stored in the PCM mem-
ory for eventual display to the service technician.
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
ACCESSING DIAGNOSTIC TROUBLE CODES
To read DTC's and to obtain cooling system data,
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
ERASING TROUBLE CODES
After the problem has been repaired, use the DRB
scan tool to erase a DTC. Refer to the appropriate
Powertrain Diagnostic Procedures service informa-
tion for operation of the DRB scan tool.
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS
ENGINE COOLING SYSTEM OVERHEATING
Establish what driving conditions caused the com-
plaint. Abnormal loads on the cooling system such as
the following may be the cause:
²PROLONGED IDLE
²VERY HIGH AMBIENT TEMPERATURE
²SLIGHT TAIL WIND AT IDLE
²SLOW TRAFFIC
²TRAFFIC JAMS
²HIGH SPEED
²STEEP GRADES
Driving techniques that avoid overheating are:
²Idle with A/C off when temperature gauge is at
end of normal range.
(1) TRAILER TOWING:
Consult Trailer Towing section of owners manual.
Do not exceed limits.
(2) RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been per-
formed on vehicle that may effect cooling system.
This may be:
²Engine adjustments (incorrect timing)
²Slipping engine accessory drive belt(s)
²Brakes (possibly dragging)
²Changed parts. Incorrect water pump, or pump
rotating in wrong direction due to belt not correctly
routed
²Reconditioned radiator or cooling system refill-
ing (possibly under filled or air trapped in system).
NOTE: If investigation reveals none of the previous
items as a cause for an engine overheating com-
plaint, refer to following Cooling System Diagnosis
charts.
These charts are to be used as a quick-reference
only. Refer to the group text for information.
DIAGNOSIS AND TESTING - COOLING SYSTEM
LEAKS
ULTRAVIOLET LIGHT METHOD
A leak detection additive is available through the
parts department that can be added to cooling sys-
tem. The additive is highly visible under ultraviolet
light (black light). Pour one ounce of additive into
cooling system. Place heater control unit in HEAT
position. Start and operate engine until radiator
upper hose is warm to touch. Aim the commercially
available black light tool at components to be
checked. If leaks are present, black light will cause
additive to glow a bright green color.
7s - 2 COOLING - 2.4LKJ
COOLING - 2.4L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
TEMPERATURE GAUGE READS
HIGH OR THE COOLANT
WARNING LAMP ILLUMINATES.
COOLANT MAY OR MAY NOT BE
LOST OR LEAKING FROM THE
COOLING SYSTEM.1. Trailer is being towed, a steep
hill is being climbed, vehicle is
operated in slow moving traffic, or
engine is being idled with very high
ambient (outside) temperatures and
the air conditioning is on. Higher
altitudes could aggravate these
conditions.1. This may be a temporary
condition and repair is not
necessary. Turn off the air
conditioning and attempt to drive the
vehicle without any of the previous
conditions. Observe the temperature
gauge. The gauge should return to
the normal range. If the gauge does
not return to the normal range,
determine the cause for overheating
and repair.
2. Is the temperature gauge reading
correctly?2. Check gauge. (Refer to Group 8J
- INSTRUMENT CLUSTER). Repair
as necessary.
3. Is the temperature warning
illuminating unnecessarily?3. Check warning lamp operation.
(Refer to Group 8J - INSTRUMENT
CLUSTER).Repair as necessary.
4. Coolant low in coolant pressure
bottle and radiator?4. Check for coolant leaks and
repair as necessary. (Refer to 7 -
COOLING - DIAGNOSIS AND
TESTING).
5. Pressure cap not installed tightly.
If cap is loose, boiling point of
coolant will be lowered. Also refer
to the following Step 6.5. Tighten cap
6. Poor seals at the radiator cap. 6. (a) Check condition of cap and
cap seals. (Refer to 7 - COOLING/
ENGINE/RADIATOR PRESSURE
CAP - DIAGNOSIS AND TESTING).
(b) Check condition of radiator filler
neck. If neck is bent or damaged,
replace radiator.
7. Coolant not flowing through
system.7. (a) Check condition of pressure
bottle cap and cap seals. (Refer to
7 - COOLING/ENGINE/RADIATOR
PRESSURE CAP - DIAGNOSIS
AND TESTING).
(b) Check condition of radiator vent
nipple. If neck is damaged, replace
radiator.
(c) Check condition of the hose from
the radiator to the coolant tank. It
should fit tight at both ends without
any kinks or tears. Replace hose if
necessary.
(d) Check pressure bottle/overflow
tank and tanks hoses for blockage.
Repair as necessary.
7s - 6 COOLING - 2.4LKJ
COOLING - 2.4L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
COOLANT LOSS TO THE
GROUND WITHOUT PRESSURE
CAP BLOWOFF. GAUGE READING
HIGH OR HOT1. Coolant leaks in radiator, cooling
system hoses, water pump or
engine.1. Pressure test and repair as
necessary. (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
DETONATION OR PRE-IGNITION
(NOT CAUSED BY IGNITION
SYSTEM). GAUGE MAY OR MAY
NOT BE READING HIGH1. Engine overheating. 1. Check reason for overheating
and repair as necessary.
2. Freeze point of coolant not
correct. Mixture is too rich or too
lean.2. Check coolant concentration.
(Refer to 7 - COOLING/ENGINE/
COOLANT - DESCRIPTION) and
adjust ratio as required.
HOSE OR HOSES COLLAPSE
WHILE ENGINE IS RUNNING1. Vacuum created in cooling
system on engine cool-down is not
being relieved through coolant
reserve/overflow system.1. (a) Radiator cap relief valve
stuck. (Refer to 7 - COOLING/
ENGINE/RADIATOR PRESSURE
CAP - DIAGNOSIS AND TESTING).
Replace if necessary
(b) Hose between coolant
reserve/overflow tank and radiator is
kinked. Repair as necessary.
(c) Vent at coolant reserve/overflow
tank is plugged. Clean vent and
repair as necessary.
(d) Reserve/overflow tank is
internally blocked or plugged. Check
for blockage and repair as
necessary.
NOISY VISCOUS FAN/DRIVE 1. Fan blades loose. 1. Replace fan blade assembly.
(Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - REMOVAL)
2. Fan blades striking a surrounding
object.2. Locate point of fan blade contact
and repair as necessary.
3. Air obstructions at radiator or air
conditioning condenser.3. Remove obstructions and/or
clean debris or insects from radiator
or A/C condenser.
4. Thermal viscous fan drive has
defective bearing.4. Replace fan drive. Bearing is not
serviceable. (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN -
REMOVAL).
KJCOOLING - 2.4L7s-9
COOLING - 2.4L (Continued)