Engine JEEP GRAND CHEROKEE 2002 WJ / 2.G Repair Manual

INSPECTION..........................52
INSTALLATION.........................52
RADIATOR PRESSURE CAP
DESCRIPTION.........................53
OPERATION...........................53
DIAGNOSIS AND TESTINGÐRADIATOR
PRESSURE CAP......................53CLEANING............................53
INSPECTION..........................54
WATER PUMP INLET TUBE
REMOVAL.............................54
INSTALLATION.........................54
COOLANT
DESCRIPTION
DESCRIPTION - ENGINE COOLANT
ETHYLENE-GLYCOL MIXTURES
CAUTION: Richer antifreeze mixtures cannot be
measured with normal field equipment and can
cause problems associated with 100 percent ethyl-
ene-glycol.
The required ethylene-glycol (antifreeze) and water
mixture depends upon the climate and vehicle oper-
ating conditions. The recommended mixture of 50/50
ethylene-glycol and water will provide protection
against freezing to -37 deg. C (-35 deg. F). The anti-
freeze concentrationmust alwaysbe a minimum of
44 percent, year-round in all climates.If percentage
is lower than 44 percent, engine parts may be
eroded by cavitation, and cooling system com-
ponents may be severely damaged by corrosion.
Maximum protection against freezing is provided
with a 68 percent antifreeze concentration, which
prevents freezing down to -67.7 deg. C (-90 deg. F). A
higher percentage will freeze at a warmer tempera-
ture. Also, a higher percentage of antifreeze can
cause the engine to overheat because the specific
heat of antifreeze is lower than that of water.
Use of 100 percent ethylene-glycol will cause for-
mation of additive deposits in the system, as the cor-
rosion inhibitive additives in ethylene-glycol require
the presence of water to dissolve. The deposits act as
insulation, causing temperatures to rise to as high as
149 deg. C (300) deg. F). This temperature is hot
enough to melt plastic and soften solder. The
increased temperature can result in engine detona-
tion. In addition, 100 percent ethylene-glycol freezes
at 22 deg. C (-8 deg. F ).
PROPYLENE-GLYCOL MIXTURES
It's overall effective temperature range is smaller
than that of ethylene-glycol. The freeze point of 50/50
propylene-glycol and water is -32 deg. C (-26 deg. F).
5 deg. C higher than ethylene-glycol's freeze point.
The boiling point (protection against summer boil-
over) of propylene-glycol is 125 deg. C (257 deg. F )at 96.5 kPa (14 psi), compared to 128 deg. C (263
deg. F) for ethylene-glycol. Use of propylene-glycol
can result in boil-over or freeze-up on a cooling sys-
tem designed for ethylene-glycol. Propylene glycol
also has poorer heat transfer characteristics than
ethylene glycol. This can increase cylinder head tem-
peratures under certain conditions.
Propylene-glycol/ethylene-glycol Mixtures can
cause the destabilization of various corrosion inhibi-
tors, causing damage to the various cooling system
components. Also, once ethylene-glycol and propy-
lene-glycol based coolants are mixed in the vehicle,
conventional methods of determining freeze point will
not be accurate. Both the refractive index and spe-
cific gravity differ between ethylene glycol and propy-
lene glycol.
DESCRIPTION - HOAT COOLANT
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL
BASE COOLANT AND IS HARMFUL IF SWAL-
LOWED OR INHALED. IF SWALLOWED, DRINK
TWO GLASSES OF WATER AND INDUCE VOMIT-
ING. IF INHALED, MOVE TO FRESH AIR AREA.
SEEK MEDICAL ATTENTION IMMEDIATELY. DO NOT
STORE IN OPEN OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY AFTER
COMING IN CONTACT WITH ETHYLENE GLYCOL.
KEEP OUT OF REACH OF CHILDREN. DISPOSE OF
GLYCOL BASE COOLANT PROPERLY, CONTACT
YOUR DEALER OR GOVERNMENT AGENCY FOR
LOCATION OF COLLECTION CENTER IN YOUR
AREA. DO NOT OPEN A COOLING SYSTEM WHEN
THE ENGINE IS AT OPERATING TEMPERATURE OR
HOT UNDER PRESSURE, PERSONAL INJURY CAN
RESULT. AVOID RADIATOR COOLING FAN WHEN
ENGINE COMPARTMENT RELATED SERVICE IS
PERFORMED, PERSONAL INJURY CAN RESULT.
CAUTION: Use of Propylene Glycol based coolants
is not recommended, as they provide less freeze
protection and less corrosion protection.
The cooling system is designed around the coolant.
The coolant must accept heat from engine metal, in
the cylinder head area near the exhaust valves and
engine block. Then coolant carries the heat to the
radiator where the tube/fin radiator can transfer the
heat to the air.
WJENGINE 7 - 25

The use of aluminum cylinder blocks, cylinder
heads, and water pumps requires special corrosion
protection. MopartAntifreeze/Coolant, 5
Year/100,000 Mile Formula (MS-9769), or the equiva-
lent ethylene glycol base coolant with organic corro-
sion inhibitors (called HOAT, for Hybrid Organic
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% Ethylene Glycol and 50% distilled
water to obtain a freeze point of -37ÉC (-35ÉF). If it
loses color or becomes contaminated, drain, flush,
and replace with fresh properly mixed coolant solu-
tion.
CAUTION: MoparTAntifreeze/Coolant, 5
Year/100,000 Mile Formula (MS-9769) may not be
mixed with any other type of antifreeze. Mixing of
coolants other than specified (non-HOAT or other
HOAT), may result in engine damage that may not
be covered under the new vehicle warranty, and
decreased corrosion protection.
COOLANT PERFORMANCE
The required ethylene-glycol (antifreeze) and water
mixture depends upon climate and vehicle operating
conditions. The coolant performance of various mix-
tures follows:
Pure Water-Water can absorb more heat than a
mixture of water and ethylene-glycol. This is for pur-
pose of heat transfer only. Water also freezes at a
higher temperature and allows corrosion.
100 percent Ethylene-Glycol-The corrosion
inhibiting additives in ethylene-glycol need the pres-
ence of water to dissolve. Without water, additives
form deposits in system. These act as insulation
causing temperature to rise to as high as 149ÉC
(300ÉF). This temperature is hot enough to melt plas-
tic and soften solder. The increased temperature can
result in engine detonation. In addition, 100 percent
ethylene-glycol freezes at -22ÉC (-8ÉF).
50/50 Ethylene-Glycol and Water-Is the recom-
mended mixture, it provides protection against freez-
ing to -37ÉC (-34ÉF). The antifreeze concentration
must alwaysbe a minimum of 44 percent, year-
round in all climates. If percentage is lower, engine
parts may be eroded by cavitation. Maximum protec-
tion against freezing is provided with a 68 percent
antifreeze concentration, which prevents freezing
down to -67.7ÉC (-90ÉF). A higher percentage will
freeze at a warmer temperature. Also, a higher per-
centage of antifreeze can cause the engine to over-
heat because specific heat of antifreeze is lower than
that of water.CAUTION: Richer antifreeze mixtures cannot be
measured with normal field equipment and can
cause problems associated with 100 percent ethyl-
ene-glycol.
COOLANT SELECTION AND ADDITIVES
The use of aluminum cylinder blocks, cylinder
heads and water pumps requires special corrosion
protection. Only MopartAntifreeze/Coolant, 5
Year/100,000 Mile Formula (glycol base coolant with
corrosion inhibitors called HOAT, for Hybrid Organic
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% distilled water to obtain to obtain a
freeze point of -37ÉC (-35ÉF). If it loses color or
becomes contaminated, drain, flush, and replace with
fresh properly mixed coolant solution.
CAUTION: Do not use coolant additives that are
claimed to improve engine cooling.
OPERATION
Coolant flows through the engine block absorbing
the heat from the engine, then flows to the radiator
where the cooling fins in the radiator transfers the
heat from the coolant to the atmosphere. During cold
weather the ethylene-glycol coolant prevents water
present in the cooling system from freezing within
temperatures indicated by mixture ratio of coolant to
water.
COOLANT LEVEL SENSOR
REMOVAL
(1) Open Hood.
(2) Disconnect electrical connector from coolant
level sensor.
(3) Pull coolant level sensor out of coolant recovery
pressure container.
INSTALLATION
NOTE: Make sure the coolant level sensor fully
seats into the rubber grommet. Failure to do so
may cause inaccurate coolant level readings and
leaks.
7 - 26 ENGINEWJ
COOLANT (Continued)

(1) Position sensor into the coolant recovery pres-
sure container (Fig. 1).
(2) Connect the coolant level sensor electrical con-
nector (Fig. 2).
(3) Close hood.
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 (Fig. 3)
mounted to the right inner fender.
RADIATOR FAN - 4.7L
DESCRIPTION
The hydraulic fan (Fig. 4) used on vehicles
equipped the 4.7L engine, replaces both the electric
fan and the engine driven mechanical fan. The
hydraulic cooling fan is integral to the fan shroud
and is located between the radiator and the engine.
The power steering pump supplies the hydraulic
fluid and pressure to rotate the cooling fan blade,
while the electrical part of the fan is controlled by
the JTEC.
The hydraulic fan drive (motor) consists of the
three major following components:
²Steering flow control valve
Fig. 1 COOLANT LEVEL SENSOR ELECTRICAL
CONNECTOR
Fig. 2 COOLANT LEVEL SENSOR REMOVAL/
INSTALLATION
Fig. 3 Coolant Reservoir / Overflow Tank
1 - COOLANT OVERFLOW HOSE
2 - COOLANT RESERVOIR/OVERFLOW TANK
3 - COOLANT LEVEL SENSOR
4 - BOLT
WJENGINE 7 - 27
COOLANT LEVEL SENSOR (Continued)

²Fan control valve
²Two stage G-rotor hydraulic drive
The hydraulic fan and drive is not serviceable.
Therefore any failure of the fan blade, hydraulic fan
drive or fan shroud requires replacement of the fan
module because the fan blade and hydraulic fan drive
are matched and balanced as a system and servicing
either separately would disrupt this balance.
For hydraulic fluid routing information refer to
(Fig. 5).
CAUTION: Do not attempt to service the hydraulic
cooling fan or fan drive separately replace the cooling
module as an assembly. Failure to do so may cause
severe damage to the hydraulic cooling fan assembly.
OPERATION
The hydraulic radiator cooling fan used on the
Grand Cherokee with the 4.7L engine replaces both
the electric fan and the engine driven mechanical
fan. The use of this hydraulic fan provides the 4.7L
equipped Grand Cherokee with heavy trailer tow
capability while at the same time reducing unneces-
sary power drain on both the engine and the vehicles
electrical system.
HYDRAULIC FAN STRATEGY
The hydraulic radiator cooling fan is controlled by
the JTEC. A PWM (Pulse With Modulated) signal
from the JTEC controls the fan from 0 to 100% of the
available fan speed. There are four inputs to the
JTEC that determine what speed percentage of fan is
required by the vehicle. These inputs are:
²Engine Coolant Temperature
²Transmission Oil Temperature
²Battery Temperature
²A/C System Pressure
By monitoring these four parameters, the JTEC
can determine if cooling airflow is required. If airflow
is required, the JTEC will slowly ramp up (speed up)
the fan speed until the parameter(s) are under con-
trol. Once the temperature or pressure is reduced to
within operating parameters the fan will ramp up,
ramp down, or hold its speed to maintain the temper-
ature / pressure requirements.
NOTE: Even if the JTEC is not requesting fan on
operation the fan blade will usually spin between
100 and 500 RPM when the vehicle is at idle. This is
due to a controlled minimum oil flow requirement
through the fan drive motor.
ACTIVATING THE HYDRAULIC FAN WITH THE DRB
Under the Engine Systems test heading, there is a
subheading. ªHydraulic fan solenoid testº, that has
the selections, on /off. Activating the fan with the
DRB will run the fan at 100% duty cycle, which will
help troubleshoot any system problems, and also help
with the deaeration procedure.
NOTE: Engine must be running to activate the fan
with the DRB.
RADIATOR COOLING FAN HYDRAULIC FLUID PATH
Hydraulic fluid is pumped through the power
steering pump, from the pump the fluid travels
though a high pressure delivery line to the fan drive
motor. As fluid is diverted through the G-rotors, rota-
tional motion is created as fluid moves from the high-
pressure (inlet) side of the motor to the low-pressure
(outlet) side. Fluid exiting the drive motor is divided
into two paths. Path one continues through a high
pressure delivery line to the vehicles steering gear to
provide steering assist. and path two sends fluid
back to the power steering pump through a low pres-
sure line. Fluid exits the steering gear under low
pressure and travels through a low pressure line to
the power steering fluid cooler to be cooled before
being returned back the the power steering fluid res-
ervoir (Fig. 5).
Fig. 4 HYDRAULIC RADIATOR COOLING FAN AND
FAN DRIVE
1 - POWER STEERING FLUID COOLER
2 - RADIATOR
3 - HIGH PRESSURE LINE FROM STEERING GEAR PUMP TO
HYDRAULIC FAN MOTOR
4 - HYDRAULIC FAN MOTOR
5 - HIGH PRESSURE LINE FROM HYDRAULIC FAN MOTOR TO
STEERING GEAR
6 - FAN SHROUD
7 - 28 ENGINEWJ
RADIATOR FAN - 4.7L (Continued)

NOTE: There is a steering flow control valve located
in the fan drive motor. This valve operates like the
flow control valve found in the typical power steer-
ing pump. Because of the design of the valve steer-
ing assist can not be effected by the radiator
cooling fan even during fan drive failure.
REMOVAL
(1) Raise vehicle on hoist.
(2) Drain cooling system.(Refer to 7 - COOLING -
STANDARD PROCEDURE)
NOTE: The hydraulic fan drive is driven by the
power steering pump. When removing lines or
hoses from fan drive assembly use a drain pan to
catch any power steering fluid that may exit the fan
drive or the lines and hoses.NOTE: When ever the high pressure line fittings are
removed from the hydraulic fan drive the O-rings
must be replaced.
(3) Disconnect two high pressure lines at hydraulic
fan drive (Fig. 6). Remove and discard o-rings from
line fittings.
(4) Disconnect low pressure return hose at hydrau-
lic fan drive (Fig. 6).
NOTE: The lower mounting bolts can only be
accessed from under vehicle.
(5) Remove two lower mounting bolts from the
shroud (Fig. 8).
(6) Lower vehicle.
(7) Disconnect the electrical connector for the fan
control solenoid.
(8) Disconnect the radiator upper hose at the radi-
ator and position out of the way.
(9) Disconnect the power steering gear outlet hose
and fluid return hose at the cooler (Fig. 7).
Fig. 5 HYDRAULIC FAN FLUID FLOW CIRCUIT
1 - POWER STEERING RESERVOIR
2 - POWER STEERING PUMP
3 - HYDRAULIC FAN DRIVE ASSEMBLY
4 - FAN BLADE5 - HYDRAULIC FAN CONTROL SOLENOID
6 - POWER STEERING OIL COOLER
7 - STEERING GEAR
WJENGINE 7 - 29
RADIATOR FAN - 4.7L (Continued)

(10) Remove two upper mounting bolts from the
shroud (Fig. 8).
(11) Remove the shroud and fan drive from vehi-
cle.
CLEANING
Clean the fan blades using a mild soap and water.
Do not use an abrasive to clean the blades.
INSTALLATION
CAUTION: There is an external ground wire con-
nected to the hydraulic fan drive located at the elec-
trical connector on the fan assembly. This ground
MUST remain connected at all times. Failure to
ensure ground wire is connected when engine is
operating can cause severe damage to the JTEC
module.
(1) Position fan drive and shroud in vehicle.
(2) Install fan shroud upper mounting bolts. Do
not tighten at this time.
(3) Install radiator upper hose onto radiator.
(4) Connect power steering cooler hoses.
(5) Raise vehicle on hoist.
(6) Install fan shroud lower mounting bolts.
Tighten to 6 N´m (50 in. lbs.).
Fig. 6 HYDRAULIC LINES/HOSES AND ELECTRICAL
CONNECTOR
1 - LOW PRESSURE RETURN HOSE
2 - HIGH PRESSURE LINE (OUTLET)
3 - HIGH PRESSURE LINE (INLET)
4 - HYDRAULIC FAN DRIVE
Fig. 7 POWER STEERING GEAR OUTLET AND
RETURN HOSES
1 - POWER STEERING COOLER RETURN HOSE
2 - POWER STEERING COOLER SUPPLY HOSE
Fig. 8 FAN SHROUD MOUNTING BOLT LOCATIONS
1 - FAN SHROUD UPPER MOUNTING BOLT LOCATIONS
2 - FAN SHROUD LOWER MOUNTING BOLT LOCATIONS
7 - 30 ENGINEWJ
RADIATOR FAN - 4.7L (Continued)

NOTE: When ever the high pressure line fittings are
removed from the hydraulic fan drive the o-rings
located on the fittings must be replaced.
(7) Lubricate the o-rings on the fittings with power
steering fluid then connect inlet and outlet high pres-
sure lines to fan drive (Fig. 9). Tighten inlet line to
49 N´m (36 ft. lbs.) tighten outlet line to 29 N´m (21.5
ft. lbs.).
(8) Connect low pressure return hose to fan drive
(Fig. 9).
(9) Lower vehicle.
(10) Install radiator upper hose.
(11) Connect electrical connector for hydraulic fan
control solenoid.
(12) Tighten fan shroud upper mounting bolts to 6
N´m (50 in. lbs.).
(13) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
CAUTION: Do not run engine with power steering
fluid below the full mark in the reservoir. Sever
damage to the hydraulic cooling fan or the engine
can occur.(14) Refill power steering fluid reservoir and bleed
air from steering system (Refer to 19 - STEERING/
PUMP - STANDARD PROCEDURE).
(15) Run engine and check for leaks.
RADIATOR FAN - 4.0L
DESCRIPTION
The radiator cooling fan used on the 4.0L engine is
an hybrid fan design. The hybrid fan system consist
of a low speed viscous driven mechanical fan and a
electrical fan (Fig. 10).
REMOVAL
(1) Disconnect negative battery cable from battery.
(2) The thermal viscous fan drive/fan blade assem-
bly is attached (threaded) to water pump hub shaft.
Remove fan blade/viscous fan drive assembly from
water pump by turning mounting nut counterclock-
wise as viewed from front (Fig. 11). Threads on vis-
cous 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-upper crossmember nuts.
(6) Remove fan shroud and fan blade/viscous fan
drive assembly as a complete unit from vehicle.
Fig. 9 HYDRAULIC LINES/HOSES AND ELECTRICAL
CONNECTOR
1 - LOW PRESSURE RETURN HOSE
2 - HIGH PRESSURE LINE (OUTLET)
3 - HIGH PRESSURE LINE (INLET)
4 - HYDRAULIC FAN DRIVEFig. 10 Radiator Cooling Fan
1 - RADIATOR
2 - ELECTRIC COOLING FAN CONNECTOR
3 - FAN SHROUD
4 - ELECTRIC COOLING FAN
WJENGINE 7 - 31
RADIATOR FAN - 4.7L (Continued)

(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.
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.
(2) Thread the fan and fan drive onto the water
pump pulley.
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.
ENGINE BLOCK HEATER
DESCRIPTION
DESCRIPTIONÐ4.7L ENGINE
WARNING: DO NOT OPERATE ENGINE UNLESS
BLOCK HEATER CORD HAS BEEN DISCONNECTED
FROM POWER SOURCE AND SECURED IN PLACE.
THE POWER CORD MUST BE SECURED IN ITS
RETAINING CLIPS AND ROUTED AWAY FROM
EXHAUST MANIFOLDS AND MOVING PARTS.
An optional engine block heater (Fig. 12) is avail-
able with all models. The heater is equipped with a
power cord. The cord is attached to an engine com-
partment component with tie-straps. The heater
warms the engine providing easier engine starting
and faster warm-up in low temperatures. The heater
is mounted in a core hole of the engine cylinder block
in place of a freeze plug with the heating element
immersed in engine coolant.
DESCRIPTIONÐ4.0L ENGINE
WARNING: DO NOT OPERATE ENGINE UNLESS
BLOCK HEATER CORD HAS BEEN DISCONNECTED
FROM POWER SOURCE AND SECURED IN PLACE.
THE POWER CORD MUST BE SECURED IN ITS
RETAINING CLIPS AND ROUTED AWAY FROM
EXHAUST MANIFOLDS AND MOVING PARTS.
Fig. 11 Fan and Viscous Fan Drive
1 - FAN AND FAN DRIVE
2 - WATER PUMP PULLEY
7 - 32 ENGINEWJ
RADIATOR FAN - 4.0L (Continued)

An optional engine block heater (Fig. 13) is avail-
able with all models. The heater is equipped with a
power cord. The cord is attached to an engine com-
partment component with tie-straps. The heater
warms the engine providing easier engine starting
and faster warm-up in low temperatures. The heater
is mounted in a core hole of the engine cylinder block
in place of a freeze plug with the heating element
immersed in engine coolant.
OPERATION
Connecting the power cord to a grounded 110-120
volt AC electrical outlet with a grounded, three wire
extension cord activates the heating element warm-
ing the engine coolant.
DIAGNOSIS AND TESTINGÐENGINE BLOCK
HEATER
If the unit does not operate (Fig. 14) (Fig. 15), pos-
sible causes can be either the power cord or the
heater element. Test the power cord for continuity
with a 110-volt voltmeter or 110-volt test light. Test
heater element continuity with an ohmmeter or a
12-volt test light.
CAUTION: To prevent damage, the power cord must
be secured in it's retainer clips and away from any
components that may cause abrasion or damage,
such as linkages, exhaust components, etc.
REMOVAL
REMOVALÐ4.7L ENGINE
(1) Disconnect negative battery cable from battery.
(2) Drain coolant from radiator (Refer to 7 -
COOLING - STANDARD PROCEDURE).
Fig. 12 Engine Block HeaterÐ4.7L
1 - ENGINE BLOCK HEATER
Fig. 13 Block Heater
1 - ENGINE BLOCK HEATER
Fig. 14 Engine Block Heater 4.0L Engine
1 - ENGINE BLOCK HEATER
WJENGINE 7 - 33
ENGINE BLOCK HEATER (Continued)

(3) Raise vehicle.
(4) Remove engine cylinder block drain plug(s)
located on the sides of cylinder block above the oil
pan rail (Fig. 16).
(5) Remove power cord from block heater.(6) Loosen screw at center of block heater. Remove
heater assembly (Fig. 17).
REMOVALÐ4.0L ENGINE
(1) Disconnect negative battery cable from battery.
(2) Drain coolant from radiator (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(3) Raise vehicle.
(4) Remove engine cylinder block drain plug(s)
located on the sides of cylinder block above the oil
pan rail (Fig. 18).
(5) Remove power cord from block heater.
(6) Loosen screw at center of block heater. Remove
heater assembly (Fig. 19).
INSTALLATION
INSTALLATIONÐ4.7L ENGINE
(1) Thoroughly clean cylinder block core hole and
block heater seat.
(2) Insert block heater assembly with element loop
pointing at twelve o'clock (Fig. 17).
(3) With block heater fully seated, tighten center
screw to 2 N´m (17 in. lbs.) torque.
(4) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(5) Start and warm the engine. Check for leaks.
INSTALLATIONÐ4.0L ENGINE
(1) Thoroughly clean cylinder block core hole and
block heater seat.
Fig. 15 Engine Block Heater 4.7L Engine
1 - ENGINE BLOCK HEATER
Fig. 16 Drain Plug - 4.7L Engine
1 - CYLINDER BLOCK DRAIN PLUG
2 - EXHAUST MANIFOLD AND HEAT SHIELD
Fig. 17 Engine Block Heater - 4.7L
1 - ENGINE BLOCK HEATER
7 - 34 ENGINEWJ
ENGINE BLOCK HEATER (Continued)