DIAGNOSIS AND TESTING - COOLING SYSTEM
AERATION
Low coolant level in a cross flow radiator will
equalize in both tanks with engine off. With engine
at running and at operating temperature, the high
pressure inlet tank runs full and the low pressure
outlet tank drops, resulting in cooling system aera-
tion. Aeration will draw air into the water pump
resulting in the following:
²High reading shown on the temperature gauge.
²Loss of coolant flow through the heater core.
²Corrosion in the cooling system.
²Water pump seal may run dry, increasing the
risk of premature seal failure.
²Combustion gas leaks into the coolant can also
cause the above problems.
DIAGNOSIS AND TESTING - COOLING SYSTEM
DEAERATION
Air can only be removed from the system by gath-
ering under the pressure cap. On the next heat up it
will be pushed past the pressure cap into the coolant
recovery bottle by thermal expansion of the coolant.
It then escapes to the atmosphere in the coolant
recovery bottle and is replaced with coolant on cool
down.
To effectively deaerate the system, multiple ther-
mal cycles of the system may be required.
NOTE: Deaeration does not occur at engine idleÐ
higher engine speeds are required. Normal driving
will deaerate cooling system.
STANDARD PROCEDURE
STANDARD PROCEDURE - COOLING SYSTEM
DRAINING
WARNING: DO NOT REMOVE OR LOOSEN THE
COOLANT PRESSURE CAP, CYLINDER BLOCK
DRAIN PLUGS, OR THE DRAINCOCK WHEN THE
SYSTEM IS HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM THE COOLANT
CAN OCCUR.
(1)Without removing radiator pressure cap
and with system not under pressure, using a
screwdriver, open the draincock. The draincock is
located on the lower left side of radiator.
(2) After the coolant recovery/reserve container is
empty, then remove coolant pressure cap (Fig. 5).
(3) Remove the cylinder block drain plug(s).
STANDARD PROCEDURE - COOLING SYSTEM
FILLING
Remove radiator pressure cap (Fig. 5) and fill sys-
tem, using a 50/50 mix of MopartAntifreeze/Coolant,
5 Year/100,000 Mile Formula and distilled water.
Continue filling system until full.Be careful not
to spill coolant on drive belts or the generator.
For cooling system capacity, (Refer to LUBRICATION
& MAINTENANCE/FLUID CAPACITIES - SPECIFI-
CATIONS).
Fill coolant recovery/reserve container (Fig. 5) to at
least the MAX mark with 50/50 solution. It may be
necessary to add coolant to the recovery/reserve con-
tainer after three or four warm up/cool down cycles
to maintain coolant level between the MAX and MIN
mark. This will allow trapped air to be removed from
the system.
STANDARD PROCEDURE - ADDING
ADDITIONAL COOLANT
The radiator cap should not be removed.
When additional coolant is needed to maintain this
level, it should be added to the coolant recovery/re-
serve container (Fig. 5). Use only 50/50 mix of ethyl-
ene glycol type antifreeze and distilled water. For the
recommeded antifreeze/coolant type (Refer to LUBRI-
CATION & MAINTENANCE/FLUID TYPES -
DESCRIPTION).
CAUTION: Do not use well water, or suspect water
supply in cooling system. A 50/50 ethylene glycol
and distilled water mix is recommended. For the
recommeded antifreeze/coolant type (Refer to
LUBRICATION & MAINTENANCE/FLUID TYPES -
DESCRIPTION).
STANDARD PROCEDURE - COOLANT LEVEL
CHECK
NOTE: Do not remove radiator cap for routine cool-
ant level inspections.
The coolant reserve system provides a quick visual
method for determining the coolant level without
removing the radiator cap.With the engine cold
and not running,simply observe the level of the
coolant in the recovery/reserve container (Fig. 5). The
coolant level should be between the MIN and MAX
marks.
7 - 4 COOLINGRS
COOLING (Continued)
SPECIFICATIONS
ACCESSORY DRIVE BELT TENSION
ACCESSORY
DRIVE BELTTENSION
2.4L ENGINE
Air Conditioning
Compressor/
GeneratorDynamic Tensioner
Power
SteeringNew
Belt534 - 756 N
178 - 212 Hz
(120 - 170
lbs.)
Used
Belt*356 - 534 N
145 - 178 Hz
(80 - 120 lbs)
*Belt is considered used after 15 minutes of run-in
time
3.3/3.8L ENGINES
Air Conditioning
CompressorDynamic
Tensioner
Generator/Water
Pump/Power
Steering
TORQUE
DESCRIPTION N´m Ft.
Lbs.In.
Lbs.
Bolt, Accessory Drive Belt
Tensioner Assembly (3.3/3.8L)28 - 250
Engine Coolant Temperature
Sensor7-60
Bolt, Generator & A/C Compressor
Drive Belt Tensioner Assembly
(2.4L)54 40 -
Bolts, Coolant Outlet Connector/
Thermostat Housing28 - 250
Bolts, Water Pump 12 - 105
Bolts , Water Pump Inlet Tube
(2.4L)12 - 105
Bolts, Water Pump Inlet Tube
(3.3/3.8L)28 - 250
Bolts, Water Pump Pulley (3.3/3.8L) 28 - 250
Screws, Radiator to A/C Condenser 5 - 45
Screws, Radiator Fan 5 - 45
Nuts, Radiator Mounting (Upper
Bracket)12 - 105
Fig. 5 Cooling System Service Locations
1 - COOLANT RECOVERY CONTAINER 3 - ENGINE OIL LEVEL DIPSTICK
2 - ENGINE OIL FILL CAP 4 - RADIATOR PRESSURE CAP
RSCOOLING7-5
COOLING (Continued)
SPECIAL TOOLS
COOLING SYSTEM
Hose Clamp Pliers 6094
Hose Clamp Pliers 8495A
Cooling System Tester 7700
Coolant Refractometer 8286
Fig. 6 TOOL 8875A
DRB IIITwith PEP Module ± OT-CH6010A
Belt Tension Gauge Adapter 8371
Belt Tension Gauge 7198A
7 - 6 COOLINGRS
COOLING (Continued)
(3) Verify belt is properly routed and engaged on
all pulleys (Fig. 5).
(4) Install drive belt shield (Fig. 8) and lower vehi-
cle.
POWER STEERING PUMP
(1) Install belt over crankshaft and power steering
pump pulleys (Fig. 5) and (Fig. 6).
(2) Apply an initial snug torque to pivot bolt (3)
and front locking nut (2) (Fig. 4).
(3) Tighten adjusting bolt (4) until proper belt ten-
sion is obtained (Fig. 4). For belt tension check pro-
cedure, (Refer to 7 - COOLING/ACCESSORY DRIVE/
DRIVE BELTS - STANDARD PROCEDURE -
CHECKING POWER STEERING BELT TENSION).
(4) Tighten pivot bolt (3) and front locking nut (2)
to 54 N´m (40 ft. lbs.) (Fig. 4).
(5) Tighten rear locking nut (1) to 54 N´m (40 ft.
lbs.) (Fig. 4).
ADJUSTMENTS
Satisfactory performance of the belt driven accesso-
ries depends on proper belt tension. Belt tensioning
should be performed with the aid of Special Tool
7198. Because of space limitations in the engine com-
partment, the use of this gauge may be restricted.
Raise the vehicle on a hoist and the remove the
splash shield to gain access to the drive belts, if nec-
essary. Adjust belt tension for either aNeworUsed
belt. For specifications, (Refer to 7 - COOLING/AC-
CESSORY DRIVE - SPECIFICATIONS).
Fig. 5 Accessory Drive Belts - 2.4L
1 - POWER STEERING PUMP PULLEY
2 - BELT TENSIONER
3 - GENERATOR PULLEY
4 - BELT - A/C AND GENERATOR
5 - A/C COMPRESSOR PULLEY
6 - CRANKSHAFT PULLEY
7 - BELT - POWER STEERING
Fig. 6 Belt Routing - 2.4L
1 - GENERATOR PULLEY
2 - A/C COMPRESSOR PULLEY
3 - CRANKSHAFT PULLEY
4 - P/S PUMP PULLEY
5 - P/S PUMP BELT
6 - BELT TENSIONER
7 - 10 ACCESSORY DRIVERS
DRIVE BELTS - 2.4L (Continued)
BELT TENSIONER - 2.4L
REMOVAL
(1) Raise vehicle on hoist.
(2) Remove the drive belt shield.
(3) Remove the generator/A/C drive belt. (Refer to
7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
(4) Remove the belt tensioner (Fig. 7).
INSTALLATION
(1) Install belt tensioner and bolt (Fig. 7). Tighten
bolt to 54 N´m (40 ft. lbs.).
(2) Install generator/A/C compressor drive belt.
(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE
BELTS - INSTALLATION)
(3) Install splash shield.
(4) Lower the vehicle.
DRIVE BELTS - 3.3/3.8L
REMOVAL
(1) Raise vehicle on hoist.
(2) Remove the drive belt shield (Fig. 8).
WARNING: DO NOT ALLOW DRIVE BELT TEN-
SIONER TO SNAP BACK, AS DAMAGE TO TEN-
SIONER AND/OR PERSONAL INJURY COULD
RESULT.(3) Position a wrench on the belt tensioner lug
(Fig. 9).
(4) Release belt tension by rotating the tensioner
counterclockwise (Fig. 9).
(5) Remove the drive belt (Fig. 10).
(6) Carefully return tensioner to its relaxed posi-
tion.
Fig. 7 Belt Tensioner - 2.4L
1 - BELT TENSIONER
2 - GENERATOR BRACKET
3 - BOLT
Fig. 8 Accessory Drive Belt Shield
1 - ATTACHING SCREW
2 - ATTACHING SCREWS
3 - SPLASH SHIELD
Fig. 9 DRIVE BELT TENSION RELEASE
1 - BELT TENSIONER LUG
2 - WRENCH
RSACCESSORY DRIVE7-11
INSTALLATION
(1) Route and position the drive belt onto all pul-
leys, except for the crankshaft (Fig. 10).
(2) Rotate belt tensioner counterclockwise until
belt can be installed onto the crankshaft pulley (Fig.
9). Slowly release belt tensioner.
(3) Verify belt is properly routed and engaged on
all pulleys (Fig. 11).
(4) Install drive belt shield (Fig. 8) and lower vehi-
cle.
BELT TENSIONER - 3.3/3.8L
REMOVAL
(1) Raise vehicle on hoist.
(2) Remove the drive belt shield.
(3) Remove the drive belt. (Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS - REMOVAL)
(4) Remove the belt tensioner (Fig. 12).
INSTALLATION
(1) Install the belt tensioner and bolt (Fig. 12).
Tighten bolt to 28 N´m (250 in. lbs.).
(2) Install the drive belt. (Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION)
(3) Install the drive belt shield.
(4) Lower the vehicle.
Fig. 10 ACCESSORY DRIVE BELT
1 - DRIVE BELT
2 - POWER STEERING PUMP PULLEY
3 - BELT TENIONER PULLEY
4 - IDLER PULLEY
5 - GENERATOR PULLEY
6 - AIR CONDITIONING COMPRESSOR PULLEY
7 - CRANKSHAFT PULLEY
8 - WATER PUMP PULLEY
Fig. 11 3.3/3.8L Belt Routing
1 - GENERATOR PULLEY
2 - A/C COMPRESSOR PULLEY
3 - CRANKSHAFT PULLEY
4 - TENSIONER PULLEY
5 - WATER PUMP PULLEY
6 - P/S PUMP PULLEY
7 - IDLER PULLEY
Fig. 12 BELT TENSIONER - 3.3/3.8L
1 - BELT TENSIONER
2 - BOLT
7 - 12 ACCESSORY DRIVERS
DRIVE BELTS - 3.3/3.8L (Continued)
ENGINE
TABLE OF CONTENTS
page page
ENGINE
DIAGNOSIS AND TESTING - ENGINE
COOLING SYSTEM....................14
CLEANING............................18
INSPECTION..........................18
COOLANT
DESCRIPTION - ENGINE COOLANT.........19
DIAGNOSIS AND TESTING - COOLANT
CONCENTRATION TESTING.............19
STANDARD PROCEDURE - COOLANT
SERVICE............................19
COOLANT RECOVERY CONTAINER
DESCRIPTION.........................20
OPERATION...........................20
DIAGNOSIS AND TESTING - COOLANT
RECOVERY SYSTEM..................20
REMOVAL.............................20
INSTALLATION.........................20
ENGINE BLOCK HEATER
DESCRIPTION.........................20
OPERATION...........................20
DIAGNOSIS AND TESTING - ENGINE BLOCK
HEATER TESTING.....................21
REMOVAL.............................21
INSTALLATION.........................21
ENGINE COOLANT TEMPERATURE SENSOR -
2.4L
DESCRIPTION.........................21
REMOVAL.............................21
INSTALLATION.........................21
ENGINE COOLANT TEMPERATURE SENSOR -
3.3/3.8L
DESCRIPTION.........................21
REMOVAL.............................21
INSTALLATION.........................23
ENGINE COOLANT THERMOSTAT
DESCRIPTION.........................23
OPERATION...........................23
DIAGNOSIS AND TESTING - ENGINE
COOLANT THERMOSTAT...............23
ENGINE COOLANT THERMOSTAT - 2.4L
REMOVAL.............................24
INSTALLATION.........................24
ENGINE COOLANT THERMOSTAT - 3.3/3.8L
REMOVAL.............................24
INSTALLATION.........................25
RADIATOR
REMOVAL.............................26INSTALLATION.........................27
RADIATOR DRAINCOCK
REMOVAL.............................27
INSTALLATION.........................27
RADIATOR PRESSURE CAP
DESCRIPTION.........................27
OPERATION...........................27
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLING
SYSTEM PRESSURE CAP TESTING.......28
DIAGNOSIS AND TESTING - RADIATOR
CAP TO FILLER NECK SEAL.............28
CLEANING............................28
INSPECTION..........................29
RADIATOR FAN
DESCRIPTION.........................29
OPERATION...........................29
DIAGNOSIS AND TESTING - RADIATOR FAN
MOTOR .............................30
REMOVAL.............................30
INSTALLATION.........................30
RADIATOR FAN RELAY
DESCRIPTION.........................31
OPERATION...........................31
REMOVAL.............................31
INSTALLATION.........................31
WATER PUMP - 2.4L
DESCRIPTION.........................32
REMOVAL.............................32
CLEANING............................32
INSPECTION..........................32
INSTALLATION.........................32
WATER PUMP - 3.3/3.8L
DESCRIPTION.........................34
REMOVAL.............................34
CLEANING............................35
INSPECTION..........................35
INSTALLATION.........................35
WATER PUMP INLET TUBE - 2.4L
DESCRIPTION.........................36
REMOVAL.............................36
INSTALLATION.........................36
WATER PUMP INLET TUBE - 3.3/3.8L
REMOVAL.............................37
INSTALLATION.........................37
RSENGINE7-13
ENGINE
DIAGNOSIS AND TESTING - ENGINE COOLING
SYSTEM
Establish what driving condition caused the cooling
system complaint. The problem may be caused by an
abnormal load on the system such as the following:
prolonged idle, very high ambient temperature, slight
tail wind at idle, slow traffic speed, traffic jam, high
speed, steep grade.
DRIVING TECHNIQUES
To avoid overheating the cooling system:
(1) Idle with A/C off when temperature gauge is at
end of normal range.
(2) Do not increase engine speed for more air flow
and coolant flow because the electric motor fan sys-
tems are not responsive to engine RPM. The added
cooling from higher coolant flow rate is more than
offset by increased heat rejection (engine heat added
to coolant).
TRAILER TOWING
Consult the owner's manual under Trailer Towing
and do not exceed specified limits.
VISUAL INSPECTION
If the cooling system problem is not caused by a
driving condition, perform a visual inspection to
determine if there was a recent service or accident
repair, including the following:
²Loose/damaged water pump drive belt
²Incorrect cooling system refilling (trapped air or
low level)
²Brakes possibly dragging
²Damaged hoses
²Loose/damaged hose clamps
²Damaged/incorrect engine thermostat
²Damaged cooling fan motor, fan blade and fan
shroud
²Damaged head gasket
²Damaged water pump
²Damaged radiator
²Damaged coolant recovery system
²Damaged heater core
²Open/shorted electrical circuits
If the visual inspection reveals none of the above
as cause for a cooling system complaint, refer to the
following diagnostic charts.
COOLING SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
PRESSURE CAP IS BLOWING
OFF STEAM AND/OR COOLANT.
TEMPERATURE GAUGE READING
MAY BE ABOVE NORMAL BUT
NOT HIGH. COOLANT LEVEL MAY
BE HIGH IN COOLANT RESERVE/
OVERFLOW TANK.1. Pressure relief valve in radiator
cap is defective, or was not
properly seated.1. Check condition of radiator cap
and cap seal. (Refer to 7 -
COOLING/ENGINE/RADIATOR
PRESSURE CAP - DIAGNOSIS
AND TESTING) Replace cap as
necessary.
2. Incorrect cap was installed. 2. Replace cap as necessary.
3. Incorrect coolant mixture. 3. Check concentration level of the
coolant. (Refer to 7 - COOLING/
ENGINE/COOLANT - DIAGNOSIS
AND TESTING) Adjust the ethylene
glycol-to-water ratio as required.
COOLANT LOSS TO THE
GROUND WITHOUT PRESSURE
CAP BLOWOFF. GAUGE IS
READING HIGH OR HOT.1. 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)
7 - 14 ENGINERS