(6) Fill cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
ENGINE COOLANT
THERMOSTAT
DESCRIPTION
The engine cooling thermostats are a wax pellet
driven, reverse poppet choke type. The thermostat is
mounted in a housing on the coolant outlet of the
engine (Fig. 8) or (Fig. 10).
OPERATION
The engine cooling thermostat is a wax pellet
driven, reverse poppet choke type. The thermostat is
designed to provide the fastest warm up possible by
preventing leakage through it and to guarantee a
minimum engine operating temperature of 88 to
93ÉC (192 to 199ÉF). The thermostat also will auto-
matically reach wide open so it will not restrict flow
to the radiator as temperature of the coolant rises in
hot weather to around 104ÉC (220ÉF). Above this
temperature the coolant temperature is controlled by
the radiator, fan, and ambient temperature, not the
thermostat.
The thermostat is operated by a wax filled con-
tainer (pellet) which is sealed. When heated coolantreaches a predetermined temperature, the wax
expands enough to overcome the closing spring and
water pump pressure, which forces the valve to open.
DIAGNOSIS AND TESTING - ENGINE COOLANT
THERMOSTAT
The thermostat is operated by a wax filled cham-
ber (pellet) which is sealed. When heated coolant
reaches a predetermined temperature the wax pellet
expands enough to overcome the closing spring and
water pump pressure, which forces the valve to open.
Coolant leakage into the pellet will cause a thermo-
stat to fail open. Do not attempt to free up a thermo-
stat with a screwdriver.
Thermostat diagnostics is included in powertrain
control module's (PCM) programing for on-board
diagnosis. The malfunction indicator light (MIL) will
illuminate and a diagnostic trouble code (DTC) will
be set when an ªopen too soonº condition occurs. Do
not change a thermostat for lack of heater perfor-
mance or temperature gauge position, unless a DTC
is present. For other probable causes, (Refer to 7 -
COOLING/ENGINE - DIAGNOSIS AND TESTING).
Thermostat failing shut is the normal long term
mode of failure, and normally, only on high mileage
vehicles. The temperature gauge will indicate this
(Refer to 7 - COOLING/ENGINE - DIAGNOSIS AND
TESTING).
ENGINE COOLANT
THERMOSTAT - 2.4L
REMOVAL
(1) Drain cooling system below the thermostat
level. (Refer to 7 - COOLING - STANDARD PROCE-
DURE)
(2) Remove radiator upper hose from the coolant
outlet housing (Fig. 7).
(3) Remove coolant outlet housing bolts and hous-
ing (Fig. 8).
(4) Remove thermostat. Discard gasket and clean
both gasket sealing surfaces.
INSTALLATION
(1) Place a new gasket (dipped in clean water) on
the coolant outlet connector surface. Position thermo-
stat with air bleed at the 12 o'clock position in ther-
mostat housing (Fig. 8).
(2) Position the coolant outlet connector and gas-
ket over the thermostat, making sure thermostat is
seated in the thermostat housing.
(3) Position outlet connector to thermostat housing
and install bolts (Fig. 8). Tighten bolts to 28 N´m
(250 in. lbs.).
Fig. 6 Engine Coolant Temperature Sensor
1 - ENGINE COOLANT TEMPERATURE SENSOR
2 - CONNECTOR - ENGINE COOLANT SENSOR
3 - FITTING - HEATER SUPPLY
RSENGINE7-23
ENGINE COOLANT TEMPERATURE SENSOR - 3.3/3.8L (Continued)
ProCarManuals.com
(4) Install the radiator upper hose to coolant outlet
housing (Fig. 7).
(5) Refill the cooling system. (Refer to 7 - COOL-
ING - STANDARD PROCEDURE)
ENGINE COOLANT
THERMOSTAT - 3.3/3.8L
REMOVAL
(1) Drain cooling system down below the thermo-
stat level. (Refer to 7 - COOLING - STANDARD
PROCEDURE)
(2) Remove radiator upper hose from coolant outlet
connector (Fig. 9).
(3) Remove coolant outlet connector bolts and con-
nector (Fig. 10).
(4) Remove thermostat from outlet connector.
(5) Discard gasket and clean both gasket sealing
surfaces.
INSTALLATION
(1) To ensure proper seating of replacement ther-
mostat, carefully remove the bulged metal from the
wall of the outlet connector recess that was created
during the staking procedure that held the OEM
thermostat in place (Fig. 11). It is not necessary to
restake the replacement thermostat into the connec-
tor.
(2) Position thermostat to coolant outlet connector.
Align the two locating notches on thermostat to the
connector (Fig. 12). This position will ensure proper
location of the thermostat air bleed.
Fig. 7 RADIATOR HOSES TO ENGINE - 2.4L
1 - UPPER HOSE
2 - LOWER HOSE
Fig. 8 Thermostat and Outlet Connector - 2.4L
Engine
1 - THERMOSTAT
2 - GASKET
3 - COOLANT OUTLET CONNECTOR
4 - BOLT
Fig. 9 RADIATOR HOSES TO ENGINE - 3.3/3.8L
1 - UPPER HOSE
2 - LOWER HOSE
7 - 24 ENGINERS
ENGINE COOLANT THERMOSTAT - 2.4L (Continued)
ProCarManuals.com
(3) Position a new gasket over the thermostat and
connector making sure thermostat is in proper posi-
tion and in the recess provided.
(4) Install thermostat and connector assembly to
the intake manifold (Fig. 10). Tighten bolts to 28
N´m (250 in. lbs.).
(5) Install the radiator upper hose to coolant outlet
connector (Fig. 9).
(6) Refill the cooling system to the proper level.
(Refer to 7 - COOLING - STANDARD PROCEDURE)
RADIATOR
DESCRIPTION
The radiator is a cross-flow type (horizontal tubes)
with design features that provide greater strength
along with sufficient heat transfer capabilities to
keep the engine satisfactorily cooled. The radiator
has plastic side tanks and aluminum cooling tubes.
OPERATION
The radiator functions as a heat exchanger, using
air flow across the exterior of the radiator tubes. This
heat is then transferred from the coolant and into
the passing air.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove radiator upper crossmember support.
(Refer to 23 - BODY/EXTERIOR/GRILLE OPENING
REINFORCEMENT - REMOVAL)
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK PLUG OR THE RADIATOR DRAINCOCK
WITH THE SYSTEM HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM COOLANT CAN
OCCUR.
(3) Drain the cooling system. (Refer to 7 - COOL-
ING - STANDARD PROCEDURE)
(4) Remove the radiator fans. (Refer to 7 - COOL-
ING/ENGINE/RADIATOR FAN - REMOVAL)
(5) Disconnect coolant reserve/recovery hose.
Fig. 10 THERMOSTAT - 3.3/3.8L ENGINE
1 - COOLANT OUTLET CONNECTOR
2 - BOLT
3 - THERMOSTAT
4 - GASKET
Fig. 11 Connector Staking Material Removal
1-STAKE
2 - OUTLET CONNECTOR
Fig. 12 Thermostat Position In Outlet Connector
1 - LOCATING NOTCH
2 - THERMOSTAT
3 - COOLANT OUTLET CONNECTOR
RSENGINE7-25
ENGINE COOLANT THERMOSTAT - 3.3/3.8L (Continued)
ProCarManuals.com
(6) Remove vapor purge solenoid from mounting
bracket.
(7) Disconnect upper and lower hoses from the
radiator (Fig. 13) or (Fig. 14).
(8) Remove the A/C condenser side brackets to
radiator attaching screws (Fig. 15). Separate the con-
denser from the radiator by lifting upward to disen-
gage from lower mounts (Fig. 15). Allow the
condenser to rest in front of radiator.
(9) Radiator can now be lifted free from engine
compartment.Care should be taken not to dam-
age radiator cooling fins or water tubes during
removal.
INSTALLATION
(1)Be sure the air seal is in position before
radiator is installed.Slide radiator down into posi-
tion. Seat the radiator with the rubber isolators into
the mounting holes provided, with a 10 lbs. force.
(2) Position air conditioning condenser onto the
radiator lower mounts and install upper screws (Fig.
15). Tighten fasteners to 5 N´m (45 in. lbs.).
(3) Install the radiator upper and lower hoses (Fig.
13) or (Fig. 14).
(4) Connect the coolant reserve/recovery hose.
(5) Connect the vapor purge solenoid to the mount-
ing bracket.
(6) Install the radiator fans. (Refer to 7 - COOL-
ING/ENGINE/RADIATOR FAN - INSTALLATION)
(7) Install the radiator upper crossmember sup-
port. (Refer to 23 - BODY/EXTERIOR/GRILLE
OPENING REINFORCEMENT - INSTALLATION)
(8) Fill the cooling system. (Refer to 7 - COOLING
- STANDARD PROCEDURE)
(9) Connect negative cable to battery.
Fig. 13 Radiator Hoses to Radiator - 2.4L
1 - UPPER HOSE
2 - LOWER HOSE
3 - HOSE SUPPORT CLIP
Fig. 14 Radiator Hoses to Radiator - 3.3/3.8L
1 - UPPER HOSE
2 - LOWER HOSE
Fig. 15 Radiator to A/C Condenser Mounting (left
mount shown, right similar)
1 - SCREW - A/C CONDENSER SIDE BRACKET TO RADIATOR
2 - LOWER MOUNT
3 - A/C CONDENSER
7 - 26 ENGINERS
RADIATOR (Continued)
ProCarManuals.com
RADIATOR DRAINCOCK
REMOVAL
CAUTION: Use of pliers on draincock is not recom-
mended. Damage may occur to radiator or drain-
cock.
NOTE: It is not necessary to remove draincock dur-
ing a routine coolant drain.
(1) Drain the cooling system. (Refer to 7 - COOL-
ING - STANDARD PROCEDURE)
(2) Open the draincock by turning it counterclock-
wise until it stops.
(3) Turn the draincock back (clockwise) 1/8 turn.
(4) Pull the draincock (Fig. 16) from the radiator
tank.
INSTALLATION
(1) Align draincock stem to radiator tank opening.
(2) Push draincock into the radiator tank opening.
(3) Tighten the draincock by turning clockwise
until it stops.
(4) Fill the cooling system. (Refer to 7 - COOLING
- STANDARD PROCEDURE)
RADIATOR PRESSURE CAP
DESCRIPTION
The cooling system pressure cap is located on the
radiator. The cap construction includes; stainless
steel swivel top, rubber seals, and retainer, main
spring, and a spring loaded valve (Fig. 17).
OPERATION
The cooling system is equipped with a pressure cap
that releases excessive pressure; maintaining a range
of 97-124 kPa (14-18 psi).
The cooling system will operate at higher than
atmospheric pressure. The higher pressure raises the
coolant boiling point thus, allowing increased radia-
tor cooling capacity.
There is also a vent valve in the center of the cap.
This valve also opens when coolant is cooling and
contracting, allowing the coolant to return to cooling
system from coolant reserve system tank by vacuum
through a connecting hose.If valve is stuck shut,
or the coolant recovery hose is pinched, the
radiator hoses will be collapsed on cool down.
Clean the vent valve (Fig. 17) and inspect cool-
ant recovery hose routing, to ensure proper
sealing when boiling point is reached.
The gasket in the cap seals the filler neck, so that
vacuum can be maintained, allowing coolant to be
drawn back into the radiator from the reserve tank.
If the gasket is dirty or damaged, a vacuum
may not be achieved, resulting is loss of coolant
and eventual overheating due to low coolant
level in radiator and engine.
Fig. 16 Draincock
1 - RADIATOR TANK
2 - DRAINCOCK
Fig. 17 Cooling System Pressure Cap Filler Neck
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - RADIATOR
8 - FILLER NECK
RSENGINE7-27
ProCarManuals.com
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLING SYSTEM
PRESSURE CAP TESTING
Dip the pressure cap in water. Clean any deposits
off the vent valve or its seat and apply cap to end of
the Pressure Cap Test Adaptor that is included with
the Cooling System Tester 7700 (Fig. 18). Working
the plunger, bring the pressure to 104 kPa (15 psi) on
the gauge. If the pressure cap fails to hold pressure
of at least 97 kPa (14 psi), replace the pressure cap.
CAUTION: The Cooling System Tester Tool is very
sensitive to small air leaks that will not cause cool-
ing 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 the tool. Turn tool
upside down and recheck pressure cap to confirm
that cap is bad.
If the pressure cap tests properly while positioned
on Cooling System Tester (Fig. 18), but will not hold
pressure or vacuum when positioned on the filler
neck. Inspect the filler neck and cap top gasket for
irregularities that may prevent the cap from sealing
properly.
DIAGNOSIS AND TESTING - RADIATOR CAP
TO FILLER NECK SEAL
The pressure cap upper gasket (seal) pressure
relief can be checked by removing the overflow hose
at the radiator filler neck nipple (Fig. 19). Attach the
Radiator Pressure Tool to the filler neck nipple and
pump air into the radiator. Pressure cap upper gas-ket should relieve at 69-124 kPa (10-18 psi) and hold
pressure at 55 kPa (8 psi) minimum.
WARNING: THE WARNING WORDS ªDO NOT OPEN
HOTº ON THE RADIATOR PRESSURE CAP IS A
SAFETY PRECAUTION. WHEN HOT, PRESSURE
BUILDS UP IN COOLING SYSTEM. TO PREVENT
SCALDING OR INJURY, THE RADIATOR CAP
SHOULD NOT BE REMOVED WHILE THE SYSTEM
IS HOT OR UNDER PRESSURE.
There is no need to remove the radiator cap at any
timeexceptfor the following purposes:
(1) Check and adjust coolant freeze point.
(2) Refill system with new coolant.
(3) Conducting service procedures.
(4) Checking for vacuum leaks.
WARNING: IF VEHICLE HAS BEEN RUN RECENTLY,
WAIT 15 MINUTES BEFORE REMOVING CAP. THEN
PLACE A SHOP TOWEL OVER THE CAP AND WITH-
OUT PUSHING DOWN ROTATE COUNTERCLOCK-
WISE TO THE FIRST STOP. ALLOW FLUIDS TO
ESCAPE THROUGH THE OVERFLOW TUBE AND
WHEN THE SYSTEM STOPS PUSHING COOLANT
AND STEAM INTO THE CRS TANK AND PRESSURE
DROPS PUSH DOWN AND REMOVE THE CAP COM-
PLETELY. SQUEEZING THE RADIATOR INLET HOSE
WITH A SHOP TOWEL (TO CHECK PRESSURE)
BEFORE AND AFTER TURNING TO THE FIRST
STOP IS RECOMMENDED.
Fig. 18 Testing Cooling System Pressure Cap
1 - PRESSURE CAP
2 - PRESSURE TESTER
Fig. 19 Radiator Pressure Cap Filler Neck
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - RADIATOR
8 - FILLER NECK
7 - 28 ENGINERS
RADIATOR PRESSURE CAP (Continued)
ProCarManuals.com
CLEANING
Use only a mild soap to clean the pressure cap.
INSPECTION
Hold the cap in your hand,top side up(Fig. 20).
The vent valve at the bottom of the cap should open.
If the rubber gasket has swollen, preventing the
valve from opening, replace the cap.
Hold the cleaned cap in your hand,upside down.
If any light can be seen between vent valve and the
rubber gasket, replace the cap.Do not use a
replacement cap that has a spring to hold the
vent shut.
A replacement cap must be of the type designed for
coolant reserve systems. This design ensures coolant
return to the radiator.
RADIATOR FAN
DESCRIPTION
The dual radiator fans are mounted to the back
side of the radiator (Fig. 21). The radiator fan consist
of the fan blade, electric motor and a support shroud
which are all serviced as an assembly.
OPERATION
RADIATOR FAN OPERATION CHART
COOLANT TEMPERATURE A/C PRESSURE TRANSAXLE OIL
TEMPERATURE
Fan
Operation
Speeds:Initial Max Initial Max Initial Max
Fan On: 104ÉC
(220ÉF)110ÉC
(230ÉF) Fan
Speed
Duty-Cycles
(Ramps-up)
from 30% to
99%1,724 Kpa
(250 psi)2,068 Kpa
(300 psi) Fan
Speed
Duty-Cycles
(Ramps-up)
from 30% to
99%96ÉC (204ÉF) 111ÉC (232ÉF)
Fan Speed
Duty Cycles
(Ramps-up)
from 30% to
99%
Fan Off: 101ÉC
(214ÉF)Fan Speed
Duty-Cycles
(Ramps-
down) from
99% to 30%1,710 Kpa
(248 psi)Fan Speed
Duty-Cycles
(Ramps-
down) from
99% to 30%89ÉC (192ÉF) Fan Speed
Duty Cycles
(Ramps-down)
from 99% to
30%
Fig. 20 Cooling System Pressure Cap
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - RADIATOR
8 - FILLER NECK
RSENGINE7-29
RADIATOR PRESSURE CAP (Continued)
ProCarManuals.com
DIAGNOSIS AND TESTING - RADIATOR FAN
MOTOR
RADIATOR FAN DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
NOISY RADIATOR FAN 1. Fan blade loose. 1. Replace fan assembly. (Refer to
7 - COOLING/ENGINE/RADIATOR
FAN - REMOVAL)
2. Fan blade striking a surrounding
object.2. Locate point of fan blade contact
and repair as necessary.
3. Air obstructions at radiator or A/C
condenser.3. Remove obstructions and/or
clean debris.
4. Electric fan motor defective. 4. Replace fan assembly. (Refer to
7 - COOLING/ENGINE/RADIATOR
FAN - REMOVAL)
ELECTRIC FAN MOTOR DOES
NOT OPERATE1. Fan relay, powertrain control
module (PCM), coolant temperature
sensor, or wiring defective.1. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
2. Defective A/C pressure
transducer.2. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
ELECTRIC RADIATOR FAN
OPERATES ALL THE TIME1. Fan relay, powertrain control
module (PCM), coolant temperature
sensor or wiring defective.1. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
2. Check for low coolant level. 2. Add coolant as necessary.
3. Defective A/C pressure
transducer.3. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
REMOVAL
There are no repairs to be made to the fan or
shroud assembly. If the fan is warped, cracked, or
otherwise damaged, it must be replaced as an assem-
bly (Fig. 21).
(1) Remove the radiator upper crossmember. (Refer
to 23 - BODY/EXTERIOR/GRILLE OPENING REIN-
FORCEMENT - REMOVAL)
(2) Disconnect the radiator fan electrical connec-
tors.
(3) Remove radiator fan(s) retaining screw (Fig.
21).
(4) Remove the radiator fan(s) by lifting upward to
release from mounts.
INSTALLATION
(1) Install the radiator fan(s) into mounts and
attaching clips on the radiator.
(2) Install radiator fan(s) attaching screws (Fig.
21). Tighten to 5 N´m (45 in. lbs.).
(3) Connect the radiator fan(s) electrical connec-
tors.
Fig. 21 Radiator Fans
1 - SCREWS - RADIATOR FAN ATTACHING
2 - RADIATOR FAN - RIGHT
3 - MOUNT - RIGHT RADIATOR FAN
4 - CLIPS - RADIATOR FAN LOWER
5 - MOUNT - LEFT RADIATOR FAN
6 - RADIATOR FAN - LEFT
7 - 30 ENGINERS
RADIATOR FAN (Continued)
ProCarManuals.com