engine cooling CHRYSLER VOYAGER 2001 Owner's Manual

CLEANING
Clean all foreign debris from belt pulley grooves.
The belt pulleys must be free of oil, grease, and cool-
ants before installing the drive belt.
INSPECTION
Belt replacement under any or all of the following
conditions is required:
²Excessive wear
²Frayed cords
²Severe glazing
Poly-V Belt system may develop minor cracks
across the ribbed side (due to reverse bending). These
minor cracks are considered normal and acceptable.
Parallel cracks are not (Fig. 5).
NOTE: Do not use any type of belt dressing or
restorer on Poly-V Belts.
INSTALLATION
GENERATOR AND AIR CONDITIONING BELT
(1) Install belt onto all pulleys except for the
crankshaft (Fig. 6).
(2) Rotate belt tensioner clockwise until belt can
be installed onto the crankshaft pulley (Fig. 3).
Slowly release belt tensioner.
(3) Verify belt is properly routed and engaged on
all pulleys (Fig. 6).
(4) Install drive belt shield (Fig. 7) and lower vehi-
cle.
POWER STEERING PUMP
(1) Install belt over crankshaft and power steering
pump pulleys (Fig. 6).
(2) Apply an initial snug torque to fasteners (D),
(E), and (F) (Fig. 4).
(3) Tighten adjusting bolt (G) until the proper ten-
sion obtained (Fig. 4). Refer to Belt Tension Specifi-
cations (Refer to 7 - COOLING/ACCESSORY DRIVE
- SPECIFICATIONS).
(4) Tighten locking nuts (D) and (F) to 54 N´m (40
ft. lbs.) (Fig. 4).
(5) Tighten pivot bolt (E) 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 Drive Belt Wear Pattern
1 - NORMAL CRACKS - BELT OK
2 - NOT NORMAL CRACKS - REPLACE BELT
Fig. 6 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
7 - 10 ACCESSORY DRIVERS
DRIVE BELTS - 2.4L (Continued)

ENGINE
TABLE OF CONTENTS
page page
ENGINE
DIAGNOSIS AND TESTING.................14
COOLING SYSTEM DIAGNOSIS...........14
CLEANING..............................17
INSPECTION............................17
COOLANT
DIAGNOSIS AND TESTING.................17
COOLANT CONCENTRATION TESTING......17
STANDARD PROCEDURE..................18
COOLANT SERVICE.....................18
COOLANT RECOVERY CONTAINER
DESCRIPTION...........................18
OPERATION.............................18
DIAGNOSIS AND TESTING.................19
COOLANT RECOVERY SYSTEM CHECK.....19
REMOVAL..............................19
INSTALLATION...........................19
ENGINE BLOCK HEATER
DESCRIPTION...........................19
OPERATION.............................19
DIAGNOSIS AND TESTING.................19
ENGINE BLOCK HEATER TESTING.........19
REMOVAL..............................19
INSTALLATION...........................19
ENGINE COOLANT TEMP SENSOR - 2.4L
DESCRIPTION...........................20
REMOVAL..............................20
INSTALLATION...........................20
ENGINE COOLANT TEMP SENSOR - 3.3/3.8L
DESCRIPTION...........................20
REMOVAL..............................20
INSTALLATION...........................21
ENGINE COOLANT THERMOSTAT
DESCRIPTION...........................21
OPERATION.............................21
DIAGNOSIS AND TESTING.................22
THERMOSTAT.........................22
ENGINE COOLANT THERMOSTAT - 2.4L
REMOVAL..............................22
INSTALLATION...........................22
ENGINE COOLANT THERMOSTAT - 3.3/3.8L
REMOVAL..............................23
INSTALLATION...........................23
RADIATOR
DESCRIPTION...........................24
OPERATION.............................24
REMOVAL..............................24INSTALLATION...........................25
RADIATOR DRAINCOCK
REMOVAL..............................25
INSTALLATION...........................25
RADIATOR PRESSURE CAP
DESCRIPTION...........................26
OPERATION.............................26
DIAGNOSIS AND TESTING.................26
COOLING SYSTEM PRESSURE CAP
TESTING.............................26
RADIATOR CAP TO FILLER NECK SEAL.....26
CLEANING..............................27
INSPECTION............................27
RADIATOR FAN
DESCRIPTION...........................27
OPERATION.............................28
DIAGNOSIS AND TESTING.................28
RADIATOR FAN MOTOR TEST.............28
REMOVAL..............................29
INSTALLATION...........................29
RADIATOR FAN RELAY
DESCRIPTION...........................29
OPERATION.............................29
REMOVAL..............................29
INSTALLATION...........................29
WATER PUMP - 2.4L
DESCRIPTION...........................30
OPERATION.............................30
REMOVAL..............................30
CLEANING..............................31
INSPECTION............................31
INSTALLATION...........................31
WATER PUMP - 3.3/3.8L
DESCRIPTION...........................32
OPERATION.............................32
REMOVAL..............................32
CLEANING..............................33
INSPECTION............................33
INSTALLATION...........................33
WATER PUMP INLET TUBE - 2.4L
DESCRIPTION...........................34
REMOVAL..............................34
INSTALLATION...........................34
WATER PUMP INLET TUBE - 3.3/3.8L
REMOVAL..............................35
INSTALLATION...........................35
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

CONDITION POSSIBLE CAUSES CORRECTION
DETONATION OR PRE-IGNITION
(NOT CAUSED BY IGNITION
SYSTEM). GAUGE MAY NOT BE
READING HIGH.1. Engine overheating. 1. Check reason for overheating
and repair as necessary.
2. Freeze point of coolant not
correct. Mixture too concentrated or
too diluted.2. Check concentration level of the
coolant. (Refer to 7 - COOLING/
ENGINE/COOLANT - DIAGNOSIS
AND TESTING) Adjust the ethylene
glycol-to-water ratio as required.
3. Incorrect cooling system
pressure cap.3. Install correct pressure cap.
HOSE(S) COLLAPSE AS ENGINE
COOLS DOWN.1. Vacuum created in cooling
system on engine cool-down is not
being relieved through coolant
recovery system.1. (a) Pressure cap relief valve
stuck. (Refer to 7 - COOLING/
ENGINE/RADIATOR PRESSURE
CAP - DIAGNOSIS AND TESTING)
Replace as necessary.
(b) Hose between the radiator and
overflow container is plugged. Clean
and repair as necessary.
(c) Vent at coolant reserve/overflow
container is plugged. Clean vent
and repair as necessary.
(d) Reserve/overflow container is
internally blocked. Clean and repair
as necessary.
INADEQUATE AIR CONDITIONER
PERFORMANCE (COOLING
SYSTEM SUSPECTED).1. Radiator and/or A/C condenser is
restricted, obstructed, or dirty
(insects, leaves, etc.).1. Remove restriction and/or clean
as necessary.
2. Electrical radiator fan not
operating when A/C is operated.2. For test procedure (Refer to
appropriate Diagnostic Information).
Repair as necessary.
3. Engine is overheating (heat may
be transferred from radiator to A/C
condenser). High underhood
temperatures due to engine
overheating may also transfer heat
to A/C components.3. Correct overheating condition.
4. All models are equipped with air
seals at the radiator and/or A/C
condenser. If these seals are
missing or damaged, not enough
air flow will be pulled through the
radiator and A/C condenser.4. Check for missing or damaged air
seals and repair as necessary.
INADEQUATE HEATER
PERFORMANCE.1. Check for a Diagnostic trouble
code (DTC).1. For procedures, (Refer to
appropriate Diagnostic Information).
Repair as necessary.
2. Coolant level low. 2. (Refer to 7 - COOLING -
STANDARD PROCEDURE) Repair
as necessary.
RSENGINE7-15
ENGINE (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
3. Obstructions in heater hose
fitting at engine or at heater core.3. Remove heater hoses at both
ends and check for obstructions.
Repair as necessary.
4. Heater hose kinked. 4. Locate kinked area and repair as
necessary.
5. Water pump is not pumping
coolant to heater core.5. When the engine is fully warmed
up, both heater hoses should be hot
to the touch. If only one of the
hoses is hot, the water pump may
not be operating correctly. Replace
components as necessary.
HEAT ODOR 1. Various heat shields are used at
certain driveline components. One
or more of these shields may be
missing.1. Locate missing shields and
replace or repair as necessary.
2. Temperature gauge reading
above the normal range.2. Refer to Gauge Is Reading High
in Temperature Gauge Indicatication
Diagnosis Chart.
3. Radiator fan operating
incorrectly.3. (Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - OPERATION)
Repair as necessary.
4. Undercoating been applied to an
unnecessary component.4. Clean undercoating as necessary.
5. Engine may be running rich,
causing the catalytic converter to
overheat5. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
POOR DRIVEABILITY
(THERMOSTAT POSSIBLY STUCK
OPEN). GAUGE MAY BE READING
LOW.1. The engine thermostat must be
operating correctly for proper
driveability, clean vehicle emissions,
and the prevention of sludge
buildup in the engine oil. Check for
a diagnostic trouble code.1. (Refer to Appropriate Diagnostic
Information) Replace thermostat, if
necessary.
STEAM IS COMING FROM FRONT
OF VEHICLE NEAR GRILL AREA
WHEN WEATHER IS WET,
ENGINE WARMED UP AND
RUNNING WITH VEHICLE
STATIONARY, OR JUST SHUT
OFF. TEMPERATURE GAUGE IS
NORMAL.1. During wet weather, moisture
(snow, ice, rain, or condensation)
on the radiator will evaporate when
the thermostat opens. The
thermostat opening allows heated
coolant into the radiator. When the
moisture contacts the hot radiator,
steam may be emitted. This usually
occurs in cold weather with no fan
or air flow to blow it away.1. Occasional steam emitting from
this area is normal. No repair is
necessary.
COOLANT COLOR 1. Coolant color is not necessarily
an indication of adequate corrosion
or temperature protection. Do not
rely on coolant color for determining
condition of coolant.1. Check the freeze point of the
coolant. (Refer to 7 - COOLING/
ENGINE/COOLANT - DIAGNOSIS
AND TESTING) Adjust the ethylene
glycol-to-water ratio as necessary.
7 - 16 ENGINERS
ENGINE (Continued)

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)

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)