CONDITION POSSIBLE CAUSES CORRECTION
COOLANT LEVEL CHANGES IN
COOLANT BOTTLE.
TEMPERATURE GAUGE IS IN
NORMAL RANGE.1. Level changes are to be
expected as coolant volume
fluctuates with engine temperature.
The coolant level will also drop as
the system removes air from a
recent filling.1. A normal condition. No repair is
necessary.
TEMPERATURE GAUGE INDICATION DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
TEMPERATURE GAUGE READING
IS INCONSISTENT (FLUCTUATES,
CYCLES OR IS ERRATIC).1. Normal reaction to fan and/or
thermostat cycle 1, Examples B
and C. During cold weather
operation with the heater blower in
the high position, the gauge reading
may drop slightly 1, Example D.
Fluctuation is also influenced by
outside temperature and heavy
loads 1, Example E.1. A normal condition. No correction
is necessary.
2. Gauge reading rises when
vehicle is brought to a stop after
heavy use (engine still running) 1,
Example F.2. A normal condition. No correction
is necessary. Gauge reading should
return to normal range 1, Example
A, after vehicle is driven.
3. Gauge reading high after
restarting a warmed-up (hot)
engine.3. A normal condition. No correction
is necessary. The gauge should
return to normal range 1, Example
A, after a few minutes of engine
operation.
4. Temperature gauge or engine
coolant temperature sensor
defective or shorted. Also, corroded
or loose wiring in the electrical
circuit.4. Check operation of gauge or
engine coolant temperature sensor
and repair, if necessary.
CLEANING
Drain cooling system and refill with clean water.
Refer to procedures in this section. Run engine with
radiator cap installed until upper radiator hose is
hot. Stop engine and drain water from system. If
water is dirty; fill, run, and drain system again, until
water runs clear.
INSPECTION
After performing a cleaning/flush procedure,
inspect all hoses, clamps and connections for deterio-
ration and leaks. Inspect radiator and heater core for
leaks.
COOLANT
DIAGNOSIS AND TESTING - COOLANT
CONCENTRATION
Coolant concentration should be checked when any
additional coolant was added to system or after a cool-
ant drain, flush and refill. The coolant mixture offers
optimum engine cooling and protection against corrosion
when mixed to a freeze point of -37ÉC (-34ÉF) to -59ÉC
(-50ÉF). The use of a hydrometer or a refractometer can
be used to test coolant concentration.
A hydrometer will test the amount of glycol in a
mixture by measuring the specific gravity of the mix-
ture. The higher the concentration of ethylene glycol,
the larger the number of balls that will float, and
higher the freeze protection (up to a maximum of
60% by volume glycol).
RSENGINE7-17
ENGINE (Continued)
A refractometer will test the amount of glycol in a
coolant mixture by measuring the amount a beam of
light bends as it passes through the fluid.
Some coolant manufactures use other types of gly-
cols into their coolant formulations. Propylene glycol
is the most common new coolant. However, propylene
glycol based coolants do not provide the same freez-
ing protection and corrosion protection and is not rec-
ommended.
CAUTION: Do not mix types of coolantÐcorrosion
protection will be severely reduced.
STANDARD PROCEDURE - COOLANT SERVICE
For engine coolant recommended service schedule,
(Refer to LUBRICATION & MAINTENANCE/MAIN-
TENANCE SCHEDULES - DESCRIPTION).
COOLANT RECOVERY
CONTAINER
DESCRIPTION
The coolant recovery/reserve system container is
mounted in the engine compartment (Fig. 2). The
container is made of plastic.
OPERATION
The coolant recovery system works with the radia-
tor pressure cap to use thermal expansion and con-
traction of the coolant to keep the coolant free of
trapped air. Provides a convenient and safe method
for checking coolant level and adjusting level at
atmospheric pressure without removing the radiator
pressure cap. It also provides some reserve coolant to
cover deaeration, evaporation, or boiling losses.
Fig. 1 Temperature Gauge Indications
7 - 18 ENGINERS
COOLANT (Continued)
DIAGNOSIS AND TESTING - COOLANT
RECOVERY SYSTEM
The cooling system is closed and designed to main-
tain coolant level to the top of the radiator.
(1) With the engineoffand cooling systemnot
under pressure, drain several ounces of coolant from
the radiator draincock while observing the coolant
recovery container. Coolant level in the container
should drop.
(2) Remove the radiator pressure cap. The coolant
level should be full to the top radiator neck. If not,
and the coolant level in the container is at or above
the MIN mark, there is an air leak in the coolant
recovery system.
(3) Check hose and hose connections to the con-
tainer, radiator filler neck or the pressure cap seal to
the radiator filler neck for leaks.
REMOVAL
(1) Raise the vehicle on hoist.
(2) Remove the lower attaching screws (Fig. 2).
(3) Lower the vehicle.
(4) Remove the upper attaching screw (Fig. 2).
(5)
Disconnect recovery hose from container (Fig. 2).
(6) Remove the recovery container.
INSTALLATION
(1) Connect the recovery hose to container (Fig. 2).
(2) Position the recovery container on the frame
rail (Fig. 2).
(3) Install the upper attaching screw and tighten
to 7 N´m (60 in. lbs.) (Fig. 2).(4) Raise the vehicle on hoist.
(5) Install the lower attaching screws and tighten
to 8.5 N´m (75 in. lbs.) (Fig. 2).
(6) Lower the vehicle.
(7) Add coolant to container as necessary. (Refer to
7 - COOLING - STANDARD PROCEDURE)
ENGINE BLOCK HEATER
DESCRIPTION
The engine block heater is available as an optional
accessory on all models. The heater is operated by
ordinary house current (110 Volt A.C.) through a
power cord located behind the radiator grille. This
provides easier engine starting and faster warm-up
when vehicle is operated in areas having extremely
low temperatures. The heater is mounted in a core
hole (in place of a core hole plug) in the engine block,
with the heating element immersed in coolant.
OPERATION
The block heater element is submerged in the cool-
ing system's coolant. When electrical power (110 volt
A.C.) is applied to the element, it creates heat. This
heat is transferred to the engine coolant. This pro-
vides easier engine starting and faster warm-up
when vehicle is operated in areas having extremely
low temperatures.
DIAGNOSIS AND TESTING - ENGINE BLOCK
HEATER
If unit does not operate, trouble can be in either
the power cord or the heater element. Test power
cord for continuity with a 110-volt voltmeter or 110-
volt test light; test heater element continuity with an
ohmmeter or 12-volt test light.
REMOVAL
(1) Drain coolant from radiator and cylinder block.
(Refer to 7 - COOLING - STANDARD PROCEDURE)
(2) Disconnect the power cord plug from heater.
(3) Loosen screw in center of heater. Remove the
heater assembly.
INSTALLATION
(1) Clean block core hole and heater seat.
(2) Insert heater assembly with element loop posi-
tionedupward.
(3) With heater seated, tighten center screw
securely to assure a positive seal.
(4) Install power cord plug to heater.
(5) Fill cooling system with coolant to the proper
level. (Refer to 7 - COOLING - STANDARD PROCE-
DURE)
Fig. 2 COOLANT RECOVERY CONTAINER
1 - UPPER BOLT ATTACHING TO BATTERY TRAY
2 - COOLANT RECOVERY/RESERVE CONTAINER
3 - UPPER BOLT
4 - HOSE
5 - LOWER BOLT (QTY. 2)
6 - LEFT SIDE FRAME RAIL
RSENGINE7-19
COOLANT RECOVERY CONTAINER (Continued)
ENGINE COOLANT TEMP
SENSOR - 2.4L
DESCRIPTION
The engine coolant temperature sensor threads
into the top of the thermostat housing (Fig. 3). New
sensors have sealant applied to the threads.
REMOVAL
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
(1) Drain the cooling system below thermostat
level. (Refer to 7 - COOLING - STANDARD PROCE-
DURE)
(2) Disconnect coolant temperature sensor electri-
cal connector.
(3) Remove coolant temperature sensor (Fig. 3).
INSTALLATION
(1) Install coolant temperature sensor (Fig. 3).
Tighten sensor to 7 N´m (60 in. lbs.).
(2) Connect electrical connector to sensor.
(3) Fill cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
ENGINE COOLANT TEMP
SENSOR - 3.3/3.8L
DESCRIPTION
The engine coolant temperature sensor threads
into a coolant passage on lower intake manifold near
the thermostat (Fig. 6). New sensors have sealant
applied to the threads.
REMOVAL
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
(1) Drain cooling system below engine coolant tem-
perature sensor level. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(2) Remove power steering reservoir and relocate
(Fig. 4). Do not disconnect hoses.
Fig. 3 Engine Coolant Temperature Sensor - 2.4L
1 - MAP SENSOR
2 - COOLANT TEMPERATURE SENSORFig. 4 Power Steering Fluid Reservoir
1 - POWER STEERING RESERVOIR
2 - BOLT - RESERVOIR TO MANIFOLD
3 - NUT - RESERVOIR TO COIL BRACKET
7 - 20 ENGINERS
(3) Remove ignition coil and bracket (Fig. 5).
(4) Disconnect coolant sensor electrical connector
(Fig. 6).
(5) Remove coolant sensor (Fig. 6).
INSTALLATION
(1) Install engine coolant temperature sensor (Fig.
6). Tighten sensor to 7 N´m (60 in. lbs.).
(2) Connect electrical connector to sensor (Fig. 6).
(3) Install ignition coil bracket (Fig. 5).
(4) Install ignition coil (Fig. 5).
(5) Install power steering reservoir (Fig. 4).
(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 coolant
reaches a predetermined temperature, the wax
expands enough to overcome the closing spring and
water pump pressure, which forces the valve to open.
Fig. 5 Fuel Rail, Ignition Coil and Bracket
1 - FUEL RAIL
2 - BOLT - FUEL RAIL
3 - NUT - IGNITION COIL
4 - BOLT - IGNITION COIL
5 - IGNITION COIL
6 - BRACKET - IGNITION COIL
7 - STUD - IGNITION COIL
8 - SEPARATOR - SPARK PLUG CABLE
9 - BRACKET - SPARK PLUG CABLE SEPARATOR
10 - BOLT - SEPARATOR BRACKET
11 - BRACKET - SPARK PLUG CABLE SEPARATOR
Fig. 6 Engine Coolant Temperature Sensor
1 - ENGINE COOLANT TEMPERATURE SENSOR
2 - CONNECTOR - ENGINE COOLANT SENSOR
3 - FITTING - HEATER SUPPLY
RSENGINE7-21
ENGINE COOLANT TEMP SENSOR - 3.3/3.8L (Continued)
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.).
(4) Install the radiator upper hose to coolant outlet
housing (Fig. 7).
(5) Refill the cooling system. (Refer to 7 - COOL-
ING - STANDARD PROCEDURE)
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
7 - 22 ENGINERS
ENGINE COOLANT THERMOSTAT (Continued)
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.(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)
Fig. 9 RADIATOR HOSES TO ENGINE - 3.3/3.8L
1 - UPPER HOSE
2 - LOWER 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
RSENGINE7-23
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.
(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.
Fig. 12 Thermostat Position In Outlet Connector
1 - LOCATING NOTCH
2 - THERMOSTAT
3 - COOLANT OUTLET CONNECTOR
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
7 - 24 ENGINERS
ENGINE COOLANT THERMOSTAT - 3.3/3.8L (Continued)