service CHRYSLER VOYAGER 1996 Service Manual

COOLING SYSTEM
CONTENTS
page page
GENERAL INFORMATION
ACCESSORY DRIVE BELTS................ 1
AUTOMATIC TRANSMISSION OIL COOLERÐ
2.4L................................. 3
COOLANT RECOVERY SYSTEM (CRS)....... 3
COOLANT.............................. 3
COOLING SYSTEM....................... 2
ENGINE BLOCK HEATER.................. 5
ENGINE THERMOSTAT.................... 3
RADIATOR PRESSURE CAP................ 4
RADIATOR............................. 3
WATER PUMPS......................... 3
DESCRIPTION AND OPERATION
COOLANT PERFORMANCE................. 6
RADIATOR HOSES AND CLAMPS........... 6
WATER PIPESÐ3.0L ENGINE.............. 6
WATER PUMPÐ3.3/3.8L ENGINES.......... 7
WATER PUMPÐ2.4L ENGINE.............. 6
WATER PUMPÐ3.0L ENGINE.............. 6
DIAGNOSIS AND TESTING
ACCESSORY DRIVE BELT.................. 7
COOLING SYSTEM DIAGNOSIS............. 8
DEAERATION.......................... 16
ELECTRIC FAN MOTOR TEST.............. 14
LOW COOLANT LEVEL AERATION.......... 15
PRESSURE TESTING RADIATOR CAP....... 15
RADIATOR CAP TO FILLER NECK SEAL
PRESSURE RELIEF CHECK.............. 15
RADIATOR COOLANT FLOW TEST.......... 14
RADIATOR FAN CONTROL................ 14
TEMPERATURE GAUGE INDICATION........ 16
TESTING COOLING SYSTEM FOR LEAKS.... 14
SERVICE PROCEDURES
COOLANT LEVEL CHECKÐROUTINE........ 16
COOLANT LEVEL SERVICE................ 16COOLANTÐADDING ADDITIONAL.......... 16
COOLING SYSTEMÐDRAINING............ 16
COOLING SYSTEMÐREFILLING........... 16
REMOVAL AND INSTALLATION
ACCESSORY DRIVE BELTSÐ2.4L.......... 23
ACCESSORY DRIVE BELTSÐ3.0L.......... 24
ACCESSORY DRIVE BELTÐ3.3/3.8L........ 24
ENGINE BLOCK HEATER................. 23
FAN MODULE.......................... 22
RADIATOR DRAINCOCK.................. 21
RADIATOR............................ 21
THERMOSTATÐ2.4L ENGINE............. 19
THERMOSTATÐ3.0L ENGINE............. 20
THERMOSTATÐ3.3/3.8L ENGINES......... 20
WATER PUMP INLET TUBEÐ2.4L ENGINE . . . 17
WATER PUMPÐ3.3/3.8L ENGINES......... 19
WATER PUMPÐ2.4L ENGINE............ 17
WATER PUMPÐ3.0L ENGINE............. 18
CLEANING AND INSPECTION
ACCESSORY DRIVE BELT................. 25
CHEMICAL CLEANING................... 25
COOLING SYSTEM CLEANING............. 25
RADIATOR PRESSURE CAP............... 25
REVERSE FLUSHING THE ENGINE......... 25
REVERSE FLUSHING THE RADIATOR....... 25
WATER PUMP......................... 24
ADJUSTMENTS
BELT TENSION CHART................... 26
BELT TENSION GAUGE METHOD........... 26
PROPER BELT TENSION................. 25
SPECIFICATIONS
COOLING SYSTEM CAPACITY............. 26
TORQUE CHART........................ 26
SPECIAL TOOLS
COOLING............................. 26
GENERAL INFORMATION
ACCESSORY DRIVE BELTS
The accessory drive system utilizes two different
style of drive belts. The conventional V-belt and the
Poly-V belt are used to drive the generator, air con-
ditioning compressor, power steering pump and waterpump. Satisfactory performance of these belts
depends on belt condition and proper belt tension.
Belt tensioning should be performed with the aid of a
Burroughs gauge Special Tool C-4162. Because of
space limitations in the engine compartment, the use
of the gauge may be restricted. Raise the vehicle on a
hoist and then remove the splash shield to gain
access to the drive belts.
NSCOOLING SYSTEM 7 - 1

COOLANT RECOVERY SYSTEM (CRS)
This system works with the radiator pressure cap
to use thermal expansion and contraction of the cool-
ant 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
and evaporation or boiling losses. All vehicles are
equipped with this system and take various shapes
and forms. (Fig. 3) shows a typical system in the typ-
ical location.
See Coolant Level Service, and Deaeration, and
Pressure Cap sections for operation and service.
AUTOMATIC TRANSMISSION OIL COOLERÐ2.4L
Oil cooler is internal oil to coolant type, mounted
in the radiator left tank (Fig. 4). Rubber oil lines feed
the oil cooler and the automatic transmission. Use
only approved transmission oil cooler hose. Since
these are molded to fit space available, molded hoses
are recommended.
ENGINE THERMOSTAT
The engine cooling thermostats are a wax pellet
driven, reverse poppet choke type. They are designed
to provide the fastest warm up possible by prevent-
ing leakage through them and to guarantee a mini-
mum engine operating temperature of 88 to 93ÉC
(192 to 199ÉF). They also automatically reach wide
open so they do 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 fan, the
radiator, and the ambient temperature, not the ther-
mostat.
WATER PUMPS
A quick test to tell whether the pump is working is
to see if the heater warms properly. A defective pump
can not circulate heated coolant through the long
heater hose.The water pump on all models can
be replaced without discharging the air condi-
tioning system.
COOLANT
The cooling system is designed around the coolant.
The coolant must accept heat from engine metal, in
the cylinder head area near the exhaust valves. Cool-
ant then carries this heat to the radiator, where the
tube/fin assemblies of these components can give it
up to the air.
The use of aluminum cylinder heads, intake mani-
folds, and water pumps requires special corrosion
protection. MopartAntifreeze or the equivalent is
recommended for best engine cooling without corro-
sion, when mixed only to a freeze point of -37ÉC
(-35ÉF) to -59ÉC (-50ÉF). If it loses color or becomes
contaminated, drain, flush, and replace with fresh
properly mixed solution.
CAUTION: Do not use well water, or suspect water
supply in cooling system. A 50/50 ethylene glycol
and distilled water mix is recommended.
RADIATOR
The radiators are cross-flow types (horizontal
tubes) with design features that provide greater
strength along with sufficient heat transfer capabili-
Fig. 3 Coolant Recovery System
Fig. 4 Automatic Transmission Oil Cooler
NSCOOLING SYSTEM 7 - 3
GENERAL INFORMATION (Continued)

DESCRIPTION AND OPERATION
WATER PIPESÐ3.0L ENGINE
The 3.0L engine uses metal piping beyond the
lower radiator hose to route (suction) coolant to the
water pump, which is located in the V of the cylinder
banks (Fig. 10).
These pipes are provided with inlet nipples for
thermostat bypass and heater return coolant hoses,
and brackets for rigid engine attachment. The pipes
employ O-rings for sealing at their interconnection
and to the water pump (Fig. 10).
COOLANT PERFORMANCE
Performance is measurable. For heat transfer pure
water excels (Formula = 1 btu per minute for each
degree of temperature rise for each pound of water).
This formula is altered when necessary additives to
control boiling, freezing, and corrosion are added as
follows:
²Pure Water (1 btu) boils at 100ÉC (212ÉF) and
freezes at 0ÉC (32ÉF)
²100 percent Glycol (.7 btu) can cause a hot
engine and detonation and will lower the freeze point
to -22ÉC (-8ÉF).
²50/50 Glycol and Water (.82 btu) is the recom-
mended combination that provides a freeze point of
-37ÉC (-35ÉF). The radiator, water pump, engine
water jacket, radiator pressure cap, thermostat, tem-
perature gauge, sending unit and heater are all
designed for 50/50 glycol.CAUTION: Do not use well water, or suspect water
supply in cooling system. A 50/50 ethylene glycol
and distilled water mix is recommended.
Where required, a 56 percent glycol and 44 percent
water mixture will provide a freeze point of -59ÉC
(-50ÉF).
CAUTION: Richer mixtures cannot be measured
with field equipment. This can lead to problems
associated with 100 percent glycol.
RADIATOR HOSES AND CLAMPS
WARNING: IF VEHICLE HAS BEEN RUN
RECENTLY, WAIT 15 MINUTES BEFORE WORKING
ON VEHICLE. RELIEVE PRESSURE BY PLACING A
SHOP TOWEL OVER THE CAP AND WITHOUT
PUSHING DOWN ROTATE IT COUNTERCLOCKWISE
TO THE FIRST STOP. ALLOW FLUIDS AND STEAM
TO ESCAPE THROUGH THE OVERFLOW TUBE.
THIS WILL RELIEVE SYSTEM PRESSURE
The hoses are removed by using constant tension
clamp pliers to compress the hose clamp.
A hardened, cracked, swollen or restricted hose
should be replaced. Do not damage radiator inlet and
outlet when loosening hoses.
Radiator hoses should be routed without any kinks
and indexed as designed. The use of molded hoses is
recommended.
Spring type hose clamps are used in all applica-
tions. If replacement is necessary replace with the
original MOPARtequipment spring type clamp.
WATER PUMPÐ2.4L ENGINE
The water pump has a diecast aluminum body and
housing with a stamped steel impeller. The water
pump bolts directly to the block. Cylinder block to
water pump sealing is provided by a rubber O-ring.
The water pump is driven by the timing belt. Refer
to Timing Belt in Group 9, Engine for component
removal providing access to water pump.
WATER PUMPÐ3.0L ENGINE
The pump bolts directly to the engine block, using
a gasket for pump to block sealing (Fig. 11). The
pump is serviced as a unit.
The water pump is driven by the timing belt. See
Timing Belt in Group 9, Engine for component
removal providing access to water pump.
Fig. 10 Engine Inlet Coolant Pipes 3.0L Engine
7 - 6 COOLING SYSTEMNS

CONDITION - AND CHECKS DIAGNOSIS
Inadequate Air Conditioning Performance - Cooling System Suspected
(1) Check for plugged air side of condenser and
radiator front and rear.(1) Wash out with low-velocity water.
(2) Assure fan runs whenever A/C head pressure
exceeds 1724 kPa (250 psi).(2) Repair as necessary.
(3) Check for missing air seals-recirculating air path.
(4) Assure correct cooling system parts.
Battery Dead - Suspect Fan Current Draw as Cause
(1) With a good, fully charged battery. (1) a - Assure fan control is operating properly.
(1) b - See charging system in Electrical, Group 8B.
Hot Smell - Suspect Cooling System
(1) Was temperature gauge high? (1) a - Yes, See9Gauge Reads High9
(1) b - No. See 2, 3, 4, and 5.
(2) Heat shields all in place? (2) a - Yes, See 3, 4, and 5.
(2) b - Repair or replace heat shields.
(3) Fan control operating properly? (3) a - Yes, See 4 and 5.
(3) b - No, See Radiator Fan Control this section.
(4) Heat exchanger air side plugged? (4) Clean as required.
(5) Engine missing or running rich? (5) Repair as required.
Poor Driveability - Suspect Failed Open Thermostat.
(1) Check diagnostics - is code 17 set? (Engine too
cold for too long)(1) If yes, change thermostat.
Poor Heater Performance - Suspect Failed Open Thermostat
(1) Does gauge read low? (1) See 3
(2) Check coolant level. (2) See 3
(3) Check diagnostics - is code 17 set? (Engine too
cold for too long)(3) If yes, change thermostat. If no, check heater
bypass valve, which should be closed except in Max
A/C or off mode; if not, see Heater and Air Conditioning
Group, 24.
Steaming, Observe Water Vapor Through Grill or Head Gap at Standstill at Idle - In Wet Weather
(1) This is normal. It is moisture, snow, or water on the
outside of the radiator that evaporates when the
thermostat opens to put hot coolant into the radiator.
This usually occurs in cold weather with no fan or air
flow to blow it away.(1) Normal condition - no service required.
NSCOOLING SYSTEM 7 - 13
DIAGNOSIS AND TESTING (Continued)

WARNING: WITH TOOL IN PLACE, PRESSURE
WILL BUILD UP FAST. EXCESSIVE PRESSURE
BUILT UP, BY CONTINUOUS ENGINE OPERATION,
MUST BE RELEASED TO A SAFE PRESSURE
POINT. NEVER PERMIT PRESSURE TO EXCEED 138
kPa (20 psi).
If the needle on the dial does not fluctuate, race
the engine a few times. If an abnormal amount of
coolant or steam emits from the tail pipe, it may
indicate a coolant leak caused by a faulty head gas-
ket, cracked engine block, or cracked cylinder head.
There may be internal leaks that can be deter-
mined by removing the oil dipstick. If water globules
appear intermixed with the oil it will indicate an
internal leak in the engine. If there is an internal
leak, the engine must be disassembled for repair.
RADIATOR CAP TO FILLER NECK SEAL PRESSURE
RELIEF CHECK
The pressure cap upper gasket (seal) pressure
relief can be checked by removing the overflow hose
at the radiator filler neck nipple (Fig. 13). 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. By add-
ing or subtracting coolant through CRS bottle.
(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 WITHOUT PUSHING DOWN ROTATE COUN-
TERCLOCKWISE TO THE FIRST STOP. ALLOW FLU-
IDS TO ESCAPE THROUGH THE OVERFLOW TUBE
AND WHEN THE SYSTEM STOPS PUSHING COOL-
ANT AND STEAM INTO THE CRS TANK AND PRES-
SURE DROPS PUSH DOWN AND REMOVE THE CAP
COMPLETELY. SQUEEZING THE RADIATOR INLET
HOSE WITH A SHOP TOWEL (TO CHECK PRES-
SURE) BEFORE AND AFTER TURNING TO THE
FIRST STOP IS RECOMMENDED.
PRESSURE TESTING RADIATOR CAP
Dip the pressure cap in water, clean any deposits
off the vent valve or its seat and apply cap to end of
Radiator Pressure Tool. 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 cap. SeeCAUTION.
If the pressure cap tests properly while positioned
on Radiator Pressure Tool (Fig. 14), but will not hold
pressure or vacuum when positioned on the radiator.
Inspect the radiator filler neck and cap top gasket for
irregularities that may prevent the cap from sealing
properly.
CAUTION: Radiator Pressure Tool is very sensitive
to small air leaks that will not cause cooling system
problems. A pressure cap that does not have a his-
tory 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.
LOW COOLANT LEVEL AERATION
Low coolant level in a cross flow radiator will
equalize in both tanks with engine off. With engine
Fig. 13 Radiator Pressure Cap Filler Neck
Fig. 14 Pressure Testing Radiator Cap
NSCOOLING SYSTEM 7 - 15
DIAGNOSIS AND TESTING (Continued)

at running operating temperature the high pressure
inlet tank runs full and the low pressure outlet tank
drops:
²Transmission oil will become hotter.
²High reading shown on the temperature gauge.
²Air in the coolant can cause loss of flow through
the heater.
²Exhaust gas leaks into the coolant also can
cause the same problems.
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 CRS
tank by thermal expansion of the coolant. It then
escapes to the atmosphere in the CRS tank and is
replaced with solid coolant on cool down.
TEMPERATURE GAUGE INDICATION
At idle with Air Conditioning off the temperature
gauge will rise slowly to about 5/8 gauge travel, the
fan will come on and the gauge will quickly drop to
about 1/2 gauge travel. This is normal.
SERVICE PROCEDURES
COOLANT LEVEL CHECKÐROUTINE
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 reserve tank (Fig. 3). The coolant level
should be between the minimum and maximum
marks.
COOLANTÐADDING ADDITIONAL
The radiator cap should not be removed.
When additional coolant is needed to maintain this
level, it should be added to the coolant reserve tank.
Use only 50/50 mix of ethylene glycol type antifreeze
and water.
CAUTION: Do not use well water, or suspect water
supply in cooling system. A 50/50 ethylene glycol
and distilled water mix is recommended.
COOLANT LEVEL SERVICE
The cooling system is closed and designed to main-
tain coolant level to the top of the radiator.
When servicing requires a coolant level check in
the radiator, the engine must beoffandnotunder
pressure. Drain several ounces of coolant from the
radiator draincock while observing the CoolantRecovery System (CRS) Tank. Coolant level in the
CRS tank should drop slightly. Then remove the radi-
ator cap. The radiator should be full to the top. If
not, and the coolant level in the CRS tank is at the
MIN mark there is an air leak in the CRS system.
Check hose or hose connections to the CRS tank,
radiator filler neck or the pressure cap seal to the
radiator filler neck for leaks.
COOLING SYSTEMÐDRAINING
Without removing radiator pressure cap and
with system not under pressure,shut engine off
and open draincock. The coolant reserve tank should
empty first, then remove radiator pressure cap. (if
not, see Testing Cooling System for leaks). To vent
2.4L engine remove the coolant temperature sensor
located above water outlet housing (Fig. 15). The 3.0/
3.3/3.8L engines have an air bleed vent on the ther-
mostat.
Removal of a sensor is required because the ther-
mostat does not have an air vent. Sensor removal
allows an air bleed for coolant to drain from the
engine block.
COOLING SYSTEMÐREFILLING
First clean system to remove old coolant, see Cool-
ing System Cleaning.
Fill the system, using the correct antifreeze as
described in the Coolant Section. Fill the system to
50 percent of its capacity with 100 percent glycol.
Then complete filling system with water. The 2.4L
engine requires venting by removal of the coolant
sensor on top of the water outlet connector (Fig. 15).
When coolant reaches this hole:
²Install coolant sensor and tighten to 7 N´m (60
in. lbs.) for 2.4L Engines.
Fig. 15 Coolant Temperature SensorÐ2.4L Engine
Drain/Fill
7 - 16 COOLING SYSTEMNS
DIAGNOSIS AND TESTING (Continued)

Continue filling system until full, this provides bet-
ter heater performance.Be careful not to spill
coolant on drive belts or the generator.
Fill coolant reserve system to at least the MAX
mark with 50/50 solution. It may be necessary to add
coolant to the reserve tank 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.
REMOVAL AND INSTALLATION
WATER PUMPÐ2.4L ENGINE
REMOVAL
(1) Disconnect negative cable from battery.
(2) Raise vehicle on a hoist. Remove right inner
splash shield.
(3) Remove accessory drive belts. Refer to Acces-
sory Drive Belt service in this section.
(4) Drain cooling system. Refer to Cooling System
Draining in this section.
(5) Support engine from the bottom and remove
right engine mount.
(6) Remove right engine mount bracket.
(7) Remove timing belt. Refer to Group 9, Engine
for procedure.
(8) Remove timing belt idler pulley.
(9) Hold camshaft sprocket with Special tool
C-4687 and adaptor C-4687-1 while removing bolt.
Remove both cam sprockets.
(10) Remove rear timing belt cover.
(11) Remove water pump attaching screws to
engine (Fig. 16).
INSTALLATION
(1) Install new O-ring gasket in water pump body
O-ring groove (Fig. 17).
CAUTION: Make sure O-ring is properly seated in
water pump groove before tightening screws. An
improperly located O-ring may cause damage to the
O-ring and cause a coolant leak.(2) Assemble pump body to block and tighten
screws to 12 N´m (105 in. lbs.) (Fig. 16). Pressurize
cooling system to 15 psi with pressure tester and
check water pump shaft seal and O-ring for leaks.
(3) Rotate pump by hand to check for freedom of
movement.
(4) Install rear timing belt cover.
(5) Install camshaft sprockets and torque bolts to
101 N´m (75 ft. lbs.).
(6) Install timing belt idler pulley and torque
mounting bolt to 61 N´m (45 ft. lbs.).
(7) Install timing belt. Refer to Group 9, Engine,
2.4L Timing Belt.
(8) Install right engine mount bracket and engine
mount. Refer to Group 9 for procedure.
(9) Fill cooling system. SeeCooling System Fill-
ing.
(10) Install accessory drive belts, Refer to Acces-
sory Drive Belts, in this section.
(11) Lower vehicle and connect battery cable.
WATER PUMP INLET TUBEÐ2.4L ENGINE
REMOVAL
(1) Drain cooling system. Refer to procedure out-
lined in this section.
(2) Remove upper radiator hose to access the hose
connections at the inlet tube.
(3) Remove lower radiator hose and heater hose
from the inlet tube (Fig. 18).
(4) Remove the 2 fasteners that hold the inlet
tube to the block.
(5) Rotate tube while removing the tube from the
engine block (Fig. 19).
INSTALLATION
(1) Inspect the O-ring for damage before installing
the tube into the cylinder block (Fig. 19).
(2) Lube O-ring with coolant and install into the
cylinder block opening.
(3) Install 2 fasteners and tighten to 12 N´m (105
in. lbs.).
(4) Connect lower radiator hose and heater hose
to inlet tube (Fig. 18).
Fig. 16 Water PumpÐ2.4L Engine
Fig. 17 Water Pump Body
NSCOOLING SYSTEM 7 - 17
SERVICE PROCEDURES (Continued)

(5) Install upper radiator hose.
(6) Fill cooling system. Refer to procedure outlined
in this section.
WATER PUMPÐ3.0L ENGINE
REMOVAL
(1) Drain cooling system. Refer to Draining Cool-
ing System in this group.
(2) To gain access to water pump refer to Group 9,
Engine for Timing Belt Removal.
(3) Remove mounting bolts.
(4) Separate pump from water inlet pipe (Fig. 20)
and (Fig. 21) and remove.
INSPECTION
Replace the water pump if it has any of the follow-
ing defects.
(1) Damage or cracks on the pump body.
(2) Coolant leaks, if the shaft seal is leaking, evi-
dent by traces of coolant leaks from vent holeAin
(Fig. 21).(3) Impeller rubs the inside of pump.
(4) Loose or rough turning bearing.
Fig. 18 Water Pump Inlet Tube Hose Connections
Fig. 19 Water Pump Inlet Tube ÐService
Fig. 20 Water PumpÐ3.0L Engine
Fig. 21 Water Pump Inspection
Fig. 22 Water Pipe O-Ring
7 - 18 COOLING SYSTEMNS
REMOVAL AND INSTALLATION (Continued)

COOLING SYSTEM
CONTENTS
page page
GENERAL INFORMATION
COOLANT PRESSURE BOTTLE............ 1
COOLING SYSTEM Ð 2.0L GASOLINE...... 1
COOLING SYSTEM Ð 2.5L VM DIESEL..... 1
LOW COOLANT LEVEL SENSOR........... 1
RADIATOR............................ 2
DESCRIPTION AND OPERATION
AUTOMATIC BELT TENSIONER............ 6
BELT TENSION......................... 5
COOLANT PERFORMANCE............... 5
PRESSURE/VENT CAP................... 4
THERMOSTAT OPERATION............... 4
THERMOSTAT......................... 6
WATER PUMP......................... 3
SERVICE PROCEDURES
ADDING ADDITIONAL COOLANT........... 7
DRAINING COOLING SYSTEM............. 7
REFILLING COOLING SYSTEM............ 7
REMOVAL AND INSTALLATION
ENGINE THERMOSTATÐ 2.0L GASOLINE . . . 9GENERATOR/POWER STEERING BELT Ð 2.5L
VM DIESEL......................... 10
RADIATOR Ð 2.5L VM DIESEL........... 9
THERMOSTAT Ð 2.5L VM DIESEL......... 9
WATER PUMP BELT Ð 2.5L VM DIESEL . . . 10
WATER PUMP Ð 2.0L GASOLINE......... 7
WATER PUMP Ð 2.5L VM DIESEL........ 8
CLEANING AND INSPECTION
WATER PUMP........................ 10
ADJUSTMENTS
BELT TENSION CHART................. 11
BELT TENSION GAUGE METHOD......... 11
SPECIFICATIONS
COOLING SYSTEM CAPACITY............ 12
TORQUE CHART...................... 12
SPECIAL TOOLS
COOLING............................ 12
GENERAL INFORMATION
COOLING SYSTEM Ð 2.0L GASOLINE
The 2.0L gasoline engine cooling system consists of
an engine cooling module, thermostat, coolant, a
water pump to circulate the coolant. The engine cool-
ing module may consist of a radiator, electric fan
motors, fan, shroud, coolant reserve system, hoses,
clamps, air condition condenser.
²When the Engine is cold: The thermostat is
closed; the cooling system has no flow through the
radiator. The coolant flows through the engine,
heater system and bypass.
²When the Engine is warm: Thermostat is open;
the cooling system has flow through radiator, engine,
heater system and bypass.
COOLING SYSTEM Ð 2.5L VM DIESEL
The cooling system has a radiator, coolant, electric
fan motors, shroud, pressure cap, thermostat, coolant
pressure bottle, hoses, a water pump to circulate the
coolant, to complete the circuit. Coolant flow for the
VM diesel engine is shown in (Fig. 1).
COOLANT PRESSURE BOTTLE
2.5L VM DIESEL
This system works with the pressure cap to use
thermal expansion and contraction of the coolant to
keep the coolant free of trapped air. It provides some
reserve coolant to cover minor leaks and evaporation
or boiling losses. The coolant pressure bottle location
for 2.5L diesel is above the cylinder head cover (Fig.
2).
LOW COOLANT LEVEL SENSOR
The low coolant level sensor checks for low coolant
level in the coolant tank. A signal will be sent from
this sensor to the Body Control Module (BCM). When
the BCM determines low coolant level for 30 contin-
uous seconds, the instrument panel mounted low
coolant level warning lamp will be illuminated. The
sensor is located on the front side of the coolant tank
(Fig. 4). For information, refer to Group 8E, Instru-
ment Panel and Gauges.
If this lamp is illuminated, it indicates the need to
fill the coolant tank and check for leaks.
NS/GSCOOLING SYSTEM 7 - 1

Initial belt adjustment is done with a adjustable
tensioner pulley. After the initial adjustment is per-
formed, an automatic belt tensioner is used to main-
tain correct belt tension at all times. Do not attempt
to check belt tension with a belt tension gauge on
vehicles equipped with an automatic belt tensioner.
Refer to Automatic Belt Tensioner in this group.
AUTOMATIC BELT TENSIONER
Drive belt tension is controlled by a spring loaded
automatic belt tensioner located below and to the
front of the engine oil filter (Fig. 12). This tensioner
is connected to a pivot bracket and a pulley (Fig. 12).
The pivot bracket rotates on a pivot pin attached to
the engine. Special machined washers with rubber
o-rings (Fig. 12) are used at each side of the pivot
bracket to help keep dirt and water away from the
pivot pin.
If a defective belt tensioner is suspected, a check of
this pivot bracket and pivot pin should be made. Cor-
rosion may have formed at the pin and may cause
the pivot bracket to stick. Belt slippage will result.
WARNING: BECAUSE OF HIGH SPRING PRES-
SURE, DO NOT ATTEMPT TO DISASSEMBLE THE
AUTOMATIC BELT TENSIONER. UNIT IS SERVICED
AS AN ASSEMBLY.
THERMOSTAT
DIAGNOSIS
Diesel engines, due to their inherent efficiency are
slower to warm up than gasoline powered engines,
and will operate at lower temperatures when the
vehicle is unloaded. Because of this, lower tempera-
ture gauge readings for diesel versus gasoline
engines may, at times be normal.
Typically, complaints of low engine coolant temper-
ature are observed as low heater output when com-
bined with cool or cold outside temperatures.
To help promote faster engine warm-up, an electric
engine block heater must be used with cool or cold
outside temperatures. This will help keep the engine
coolant warm when the vehicle is parked. Use the
block heater if the outside temperature is below 4ÉC
(40ÉF).Do not use the block heater if the out-
side temperature is above 4ÉC (40ÉF).
TESTING
NOTE: The DRB scan tool shoud be used to moni-
tor engine coolant temperature on the diesel
engine. Refer to the 1998 GS Powertrain Diagnostic
Manual for thermostat diagnosis procedure.
Fig. 12 Automatic Belt Tensioner Assembly
7 - 6 COOLING SYSTEMNS/GS
DESCRIPTION AND OPERATION (Continued)