Jeep Grand Cherokee WJ. Manual - part 717

DIAGNOSIS AND TESTING - RADIATOR FLOW
TEST

There is coolant flow through the coolant recovery

container (bottle) before and after the thermostat
opens. If engine is cold, idle engine until normal
operating temperature is reached. Then feel the
upper radiator hose. If the hose is hot, the thermo-
stat is open and water is circulating through the
cooling system.

CAUTION: Do not remove the vent valve to insert a
temperature gauge thought the opening , coolant
will spill out of the system and the engine will not
be filled with coolant up to the heads. Major dam-

age could happen if you run the engine in this con-
dition.

SPECIFICATIONS

SPECIFICATIONS - COOLING SYSTEM

SPECIFICATIONS

DESCRIPTION

SPECIFICATION

3.1L Diesel Engine

9.8 Liters (10.4 qts.)

Thermostat Starts to
Open

80°C (176°F)

TORQUE SPECIFICATIONS

DESCRIPTION

N·m

Ft. Lbs.

In. Lbs.

Automatic Belt Tensioner-to-mounting

Bracket Bolt (1)

Automatic Belt Tensioner to Block Bolts (2)

120

Fan Shroud-to-Radiator Mounting Bolts

Fan Blade-to-Thermal Viscous Fan Drive

Bolts

Hose Clamps

Radiator-to-A/C Condensor Isolator Nuts

Thermal Viscous Fan Drive-to-Fan Hub

Bolts

Thermostat Housing Bolts

Water Pump Mounting Bolts

Water Pump Pulley Bolts

ENGINE 3.1L DIESEL

7s - 13

ENGINE 3.1L DIESEL (Continued)

2001 JEEP GRAND CHEROKEE

COOLANT LEVEL SENSOR

DESCRIPTION

The low coolant level sensor checks for low coolant

level in the coolant tank. A signal will be sent from
this sensor to the powertrain control module (PCM).
When the PCM determines low coolant level, the
instrument panel mounted low coolant level warning
lamp will be illuminated. The sensor is located on the
top of the coolant tank (Fig. 2). For information, refer
to Instrument Cluster.

OPERATION

When the coolant level gets low a signal will be

sent from this sensor to the powertrain control mod-
ule (PCM). When the PCM determines low coolant
level, the instrument panel mounted low coolant level
warning lamp is illuminated. The sensor is located
on the front of the coolant tank (Fig. 2). For informa-
tion, refer to Group 8J, Instrument Cluster.

If this lamp is illuminated, it indicates the need for

service.

REMOVAL

(1) Disconnect the negative battery cable.
(2) Partially drain the cooling system.
(3) Disconnect the coolant level sensor electrical

connector.

(4) Twist and remove the sensor from the coolant

tank.

INSTALLATION

(1) Install coolant level sensor in coolant tank.

(2) Connect the coolant level sensor electrical con-

nector.

(3) Refill cooling system.
(4) Connect the negative battery cable.

Fig. 2 COOLANT LEVEL SENSOR LOCATION

1 - LOW COOLANT LEVEL SENSOR
2 - COOLANT RECOVERY HOSE
3 - PRESSURIZED COOLANT RESERVE/OVERFLOW TANK
4 - OVERFLOW HOSE

7s - 14

ENGINE 3.1L DIESEL

2001 JEEP GRAND CHEROKEE

ENGINE 4.0L

TABLE OF CONTENTS

page

RADIATOR FAN - 4.0L

DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . 16

RADIATOR - 4.0L

DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . 18

COOLANT LEVEL SENSOR

REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . 19

ENGINE COOLANT TEMP SENSOR

DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
OPERATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . 20

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. 1).

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. 2). Threads on vis-
cous fan drive are RIGHT 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.

Fig. 1 Radiator Cooling Fan

1 - RADIATOR
2 - ELECTRIC COOLING FAN CONNECTOR
3 - FAN SHROUD
4 - ELECTRIC COOLING FAN

Fig. 2 Fan and Viscous Fan Drive

1 - FAN AND FAN DRIVE
2 - WATER PUMP PULLEY

ENGINE 4.0L

7s - 15

2001 JEEP GRAND CHEROKEE

(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 not place 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:

NOT

ATTEMPT

BEND

STRAIGHTEN FAN BLADES IF FAN IS NOT WITHIN
SPECIFICATIONS.

CAUTION:

fan

blade

assembly

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.

RADIATOR - 4.0L

DESCRIPTION

All vehicles are equipped with a cross flow type

radiator with plastic side tanks (Fig. 3).

Plastic tanks, while stronger than brass, are sub-

ject to damage by impact, such as from tools or
wrenches. Handle radiator with care.

REMOVAL

WARNING:

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. 4). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS.
ALWAYS WEAR SAFETY GLASSES WHEN SERVIC-
ING CONSTANT TENSION CLAMPS.

Fig. 3 Cross Flow Radiator—Typical

1 - RADIATOR

7s - 16

ENGINE 4.0L

RADIATOR FAN - 4.0L (Continued)

2001 JEEP GRAND CHEROKEE

Content .. 715 716 717 718 ..