CONDITION POSSIBLE CAUSES CORRECTION
13. Brakes dragging. 13. Check brakes. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANI-
CAL - DIAGNOSIS AND TESTING)
TEMPERATURE GAUGE READ-
ING INCONSISTENT ( ERRATIC,
CYCLES OR FLUCTUATES)1. Heavy duty cooling system, ex-
tream cold ambient (outside) tem-
perature or heater blower motor in
high position.1. None. System operating norma-
ly.
2. Temperature gauge or gauge
sensor defective.2. Check gauge. (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING)
3. Temporary heavy usage or load. 3. None. Normal condition.
4. Air traped in cooling system. 4. Fill cooling system (Refer to 7 -
COOLING - STANDARD PROCE-
DURE).
5. Water pump 5. Replace water pump.
6. Air leak on suction side of water
pump.6. Check for leak. (Refer to 7 -
COOLING - DIAGNOSIS AND
TESTING)
RADIATOR CAP LEAKING STEAM
AND /OR COOLANT INTO RES-
ERVOIR BOTTLE. (TEMPERA-
TURE GAUGE MAY READ HIGH)1. Radiator cap defective. 1. Replace radiator cap.
2. Radiator neck surface damaged. 2. Replace radiator.
HOSE OR HOSES COLLAPSE
WHEN ENGINE IS COOLING.1. Vacuum created in cooling sys-
tem on engine cool-down is not
being relieved through coolant re-
servior/overflow system.1. Replace radiator cap, check vent
hose between radiator and reser-
voir bottle for blockage also check
reservoir bottle vent for blockage.
NOISY FAN 1. Fan blade(s) loose, damaged. 1. Replace fan blade assembly.
2. Thermal viscous fan drive. 2. None. Normal condition.
3. Fan blades striking surrounding
objects.3. Locate contact point and repair
as necessary.
4. Thermal viscous fan drive bear-
ing.4. Replace viscous fan drive as-
sembly.
5. Obstructed air flow through radi-
ator.5. Remove obstruction.
INADEQUATE AIR CONDITIONER
PERFORMANCE (COOLING SYS-
TEM SUSPECTED)1. Radiator and/or A/C condenser
air flow obstructed.1. Remove obstruction and/or
clean.
2. Thermal viscous fan drive not
working.2. Check fan drive. (Refer to 7 -
COOLING/ENGINE/FAN DRIVE
VISCOUS CLUTCH - DIAGNOSIS
AND TESTING)
3. Air seals around radiator dam-
aged or missing.3. Inspect air seals, repair or re-
place as necessary.
VACOOLING 7 - 3
CONDITION POSSIBLE CAUSES CORRECTION
INADEQUATE HEATER PERFOR-
MANCE. GUAGE MAY OR MAY
NOT READ LOW.1. Heavy duty cooling system, and
cooler ambient temperatures.1. None. Normal condition.
2. Obstruction in heater hoses. 2. Remove hoses, remove obstruc-
tion.
3. Water pump damaged. 3. Replace water pump.
HEAT ODOR 1. Damaged or missing drive line
heat shields.1. Repair or replace damaged or
missing heat shields.
2. Thermal viscous fan drive dam-
aged.2. Check thermal viscous fan drive.
(Refer to 7 - COOLING/ENGINE/
FAN DRIVE VISCOUS CLUTCH -
DIAGNOSIS AND TESTING)
7 - 4 COOLINGVA
ENGINE
TABLE OF CONTENTS
page page
COOLANT
DESCRIPTION..........................9
DIAGNOSIS AND TESTING
COOLING SYSTEM LEAKS..............10
STANDARD PROCEDURE
ADDING ADDITIONAL COOLANT.........12
DRAINING COOLING SYSTEM...........12
REFILLING COOLING SYSTEM...........13
COOLANT LEVEL SENSOR
REMOVAL.............................13
INSTALLATION.........................14
RADIATOR FAN
REMOVAL.............................14
INSTALLATION.........................14
ENGINE BLOCK HEATER
REMOVAL.............................14
INSTALLATION.........................15
ENGINE COOLANT TEMP SENSOR
DESCRIPTION.........................15REMOVAL.............................15
INSTALLATION.........................15
ENGINE COOLANT THERMOSTAT
REMOVAL.............................16
INSTALLATION.........................16
FAN DRIVE VISCOUS CLUTCH
REMOVAL.............................17
INSTALLATION.........................17
RADIATOR
REMOVAL.............................17
INSTALLATION.........................19
RADIATOR PRESSURE CAP
DESCRIPTION.........................19
OPERATION...........................20
DIAGNOSIS AND TESTING - RADIATOR
PRESSURE CAP......................20
WATER PUMP
REMOVAL.............................20
INSTALLATION.........................22
COOLANT
DESCRIPTION
Coolant flows through the engine water jackets
and cylinder heads absorbing heat produced by the
engine during operation. The coolant carries heat to
the radiator and heater core. Here it is transferred to
ambient air passing through the radiator and heater
core fins.
The required ethylene-glycol (antifreeze) and water
mixture depends upon the climate and vehicle oper-
ating conditions. The recommended mixture of 50/50
ethylene-glycol and water will provide protection
against freezing to -37É C (-35É F). The antifreeze
concentrationmust alwaysbe a minimum of 44 per-
cent, year-round in all climates.If percentage is
lower than 44 percent, engine parts may be
eroded by cavitation, and cooling system com-
ponents may be severely damaged by corrosion.
Maximum protection against freezing is provided
with a 68 percent antifreeze concentration, which
prevents freezing down to -67.7É C (-90É F). A higher
percentage will freeze at a warmer temperature.
Also, a higher percentage of antifreeze can cause the
engine to overheat because the specific heat of anti-
freeze is lower than that of water.100 Percent Ethylene - Glycol - Should Not Be Used in
Chrysler Vehicles
Use of 100 percent ethylene-glycol will cause for-
mation of additive deposits in the system, as the cor-
rosion inhibitive additives in ethylene-glycol require
the presence of water to dissolve. The deposits act as
insulation, causing temperatures to rise to as high as
149É C (300É F). This temperature is hot enough to
melt plastic and soften solder. The increased temper-
ature can result in engine detonation. In addition,
100 percent ethylene-glycol freezes at -22É C (-8É F ).
Propylene - glycol Formulations - Should Not Be Used in
Chrysler Vehicles
Propylene-glycol formulations do not meet
Chrysler coolant specifications.It's overall effec-
tive temperature range is smaller than that of ethyl-
ene-glycol. The freeze point of 50/50 propylene-glycol
and water is -32É C (-26É F). 5É C higher than ethyl-
ene-glycol's freeze point. The boiling point (protection
against summer boil-over) of propylene-glycol is 125É
C (257ÉF)at96.5 kPa (14 psi), compared to 128É C
(263É F) for ethylene-glycol. Use of propylene-glycol
can result in boil-over or freeze-up in Chrysler vehi-
cles, which are designed for ethylene-glycol. Propy-
lene glycol also has poorer heat transfer
characteristics than ethylene glycol. This can
increase cylinder head temperatures under certain
conditions.
VAENGINE 7 - 9
Propylene - glycol / Ethylene - glycol Mixtures - Should Not
Be Used in Chrysler Vehicles
Propylene-glycol/ethylene-glycol Mixtures can
cause the destabilization of various corrosion inhibi-
tors, causing damage to the various cooling system
components. Also, once ethylene-glycol and propy-
lene-glycol based coolants are mixed in the vehicle,
conventional methods of determining freeze point will
not be accurate. Both the refractive index and spe-
cific gravity differ between ethylene glycol and propy-
lene glycol.
CAUTION: Richer antifreeze mixtures cannot be
measured with normal field equipment and can
cause problems associated with 100 percent ethyl-
ene-glycol.
DIAGNOSIS AND TESTING
COOLING SYSTEM LEAKS
ULTRAVIOLET LIGHT METHOD
A leak detection additive is available through the
parts department that can be added to cooling sys-
tem. The additive is highly visible under ultraviolet
light (black light). Pour one ounce of additive into
cooling system. Place heater control unit in HEAT
position. Start and operate engine until radiator
upper hose is warm to touch. Aim the commercially
available black light tool at components to be
checked. If leaks are present, black light will cause
additive to glow a bright green color.
The black light can be used in conjunction with a
pressure tester to determine if any external leaks
exist (Fig. 1).
PRESSURE TESTER METHOD
The engine should be at normal operating temper-
ature. Recheck the system cold if cause of coolant
loss is not located during the warm engine examina-
tion.
WARNING: Hot, pressurized coolant can cause
injury by scalding.
Carefully remove coolant recovery pressure con-
tainer cap and check coolant level. Push down on cap
to disengage it from stop tabs. Wipe inside of con-
tainer and examine lower inside sealing seat for
nicks, cracks, paint, dirt and solder residue. Inspect
radiator-to- pressure container hose for internal
obstructions. Insert a wire through the hose to be
sure it is not obstructed.
Inspect cams on outside of pressure container. If
cams are damaged, seating of pressure cap valve and
tester seal will be affected.
Attach pressure tester (7700 or an equivalent) to
coolant pressure container (Fig. 2).
Fig. 1 Leak Detection Using Black Light - Typical
1 - TYPICAL BLACK LIGHT TOOL
7 - 10 ENGINEVA
Operate tester pump to apply 103.4 kPa (15 psi)
pressure to system. If hoses enlarge excessively or
bulges while testing, replace as necessary. Observe
gauge pointer and determine condition of cooling sys-
tem according to following criteria:
Holds Steady:If pointer remains steady for two
minutes, serious coolant leaks are not present in sys-
tem. However, there could be an internal leak that
does not appear with normal system test pressure. If
it is certain that coolant is being lost and leaks can-
not be detected, inspect for interior leakage or per-
form Internal Leakage Test.
Drops Slowly:Indicates a small leak or seepage
is occurring. Examine all connections for seepage or
slight leakage with a flashlight. Inspect radiator,
hoses, gasket edges and heater. Seal small leak holes
with a Sealer Lubricant (or equivalent). Repair leak
holes and inspect system again with pressure
applied.
Drops Quickly:Indicates that serious leakage is
occurring. Examine system for external leakage. If
leaks are not visible, inspect for internal leakage.
Large radiator leak holes should be repaired by a
reputable radiator repair shop.
INTERNAL LEAKAGE INSPECTION
Remove engine oil pan drain plug and drain a
small amount of engine oil. If coolant is present in
the pan, it will drain first because it is heavier than
oil. An alternative method is to operate engine for a
short period to churn the oil. After this is done,
remove engine dipstick and inspect for water glob-ules. Also inspect transmission dipstick for water
globules and transmission fluid cooler for leakage.
WARNING: WITH RADIATOR PRESSURE TESTER
TOOL INSTALLED ON RADIATOR, DO NOT ALLOW
PRESSURE TO EXCEED 110 KPA (20 PSI). PRES-
SURE WILL BUILD UP QUICKLY IF A COMBUSTION
LEAK IS PRESENT. TO RELEASE PRESSURE,
ROCK TESTER FROM SIDE TO SIDE. WHEN
REMOVING TESTER, DO NOT TURN TESTER MORE
THAN 1/2 TURN IF SYSTEM IS UNDER PRESSURE.
Operate engine without pressure cap on coolant
container until thermostat opens. Attach a Pressure
Tester to container. If pressure builds up quickly it
indicates a combustion leak exists. This is usually
the result of a cylinder head gasket leak or crack in
engine. Repair as necessary.
If there is not an immediate pressure increase,
pump the Pressure Tester. Do this until indicated
pressure is within system range of 110 kPa (16 psi).
Fluctuation of gauge pointer indicates compression or
combustion leakage into cooling system.
Because the vehicle is equipped with a catalytic
converter,do notremove spark plug cables or short
out cylinders to isolate compression leak.
If the needle on dial of pressure tester does not
fluctuate, race engine a few times to check for an
abnormal amount of coolant or steam. This would be
emitting from exhaust pipe. Coolant or steam from
exhaust pipe may indicate a faulty cylinder head gas-
ket, cracked engine cylinder block or cylinder head.
A convenient check for exhaust gas leakage into
cooling system is provided by a commercially avail-
able Block Leak Check tool. Follow manufacturers
instructions when using this product.
COMBUSTION LEAKAGE TEST - WITHOUT PRES-
SURE TESTER
DO NOT WASTE reusable coolant. If solution is
clean, drain coolant into a clean and suitably marked
container for reuse.
WARNING: Do not remove cylinder block drain
plugs or loosen radiator drain with system hot and
under pressure. serious burns from coolant can
occur.
Drain sufficient coolant to allow thermostat
removal.
Remove accessory drive belt.
Add coolant to pressure container to bring level to
within 6.3 mm (1/4 in) of top of thermostat housing.
CAUTION: Avoid overheating. Do not operate
engine for an excessive period of time. Open drain-
cock immediately after test to eliminate boil over.
Fig. 2 PRESSURE TESTING
1 - PRESSURE RESERVOIR CAP
2 - PRESSURE RESERVOIR
3 - PRESSURE TESTER
VAENGINE 7 - 11
REFILLING COOLING SYSTEM
(1) Tighten the radiator drain and the cylinder
block drain plug(s) (if removed). Tighten the engine
drain plug to 30 N´m (22 lbs. ft.).
(2) Fill system using a 50/50 mixture of ethylene-
glycol antifreeze and low mineral content water. Fill
radiator to top and add sufficient coolant to the cool-
ant recovery pressure container to raise level to
COLD MINIMUM mark.
(3) With heater control unit in the HEAT position,
operate engine with container cap in place.
(4) After engine has reached normal operating
temperature, shut engine off and allow it to cool.
When engine is cooling down, coolant will be drawn
into the radiator from the pressure container.
(5) Add coolant to pressure container as necessary.
Only add coolant to the container when the
engine is cold. Coolant level in a warm engine
will be higher due to thermal expansion.To
purge the cooling system of all air, this heat up/cool
down cycle (adding coolant to cold engine) must be
performed three times. Add necessary coolant to raisecontainer level to the COLD MINIMUM mark after
each cool down period.
COOLANT LEVEL SENSOR
REMOVAL
WARNING: Risk of injury to skin and eyes due to
scalding from hot coolant. Do not open the cooling
system unless the temperature is below 194Éf
(90Éc). Wear protective clothing and eye wear. Risk
of poisoning if coolant is swallowed. Store coolant
in proper and appropriately marked containers.
NOTE: Drain coolant from radiator drain plug only.
(1) Drain coolant until the coolant reservoir is
emptied.
(2) Disconnect the wiring harness electrical con-
nector.
Fig. 3 DRAINING COOLANT SYSTEM
1 - DRAIN HOSE 3 - RADIATOR DRAIN PLUG
2 - ENGINE DRAIN PLUG 4 - DRAIN HOSE
VAENGINE 7 - 13
(3) Turn the level sensor 90 degrees clockwise, lift
up and out of the container (Fig. 4).
INSTALLATION
(1) Align coolant level sensor with coolant
reservior access whole, press down while turning
counterclockwise 90 degrees to seat sensor (Fig. 4).
(2) Connect coolant level sensor electrical connec-
tor (Fig. 4).
(3) Refill cooling system to proper level (Refer to 7
- COOLING/ENGINE/COOLANT - STANDARD PRO-
CEDURE).
(4) Inspect for leaks.
RADIATOR FAN
REMOVAL
(1) Disconnect the negative battery cable.
(2) Detach coolant line from lower radiator shroud.
(3) The radiator fan assembly is attached
(threaded) to the water pump hub shaft (Fig. 5).
Remove the fan blade/viscous fan drive assembly
from the water pump by turning the mounting nut
counterclockwise as viewed from the front. Threads
on the radiator fan drive areRIGHT-HAND.A36
MM Fan Wrench should be used to prevent pulley
from rotating (Fig. 5).(4) Remove radiator fan shroud and radiator fan.
(Fig. 5).
NOTE: Store the viscous fan clutch in the upright
position. DO NOT place down flat.
INSTALLATION
(1) Install fan blade to viscous clutch. Tighten
bolts to 9 N´m (80 lbs. in.). (Fig. 5).
(2) Install fan and clutch along with fan shroud in
to engine bay area (Fig. 5).
(3) Install the center bolt of the viscous clutch.
Tighten bolt to 45 N´m (33 lbs. ft.). (Fig. 5)
(4) Attach coolant line to lower radiator shroud.
(5) Properly align and clip the fan shroud into
place.
(6) Connect negative battery cable.
ENGINE BLOCK HEATER
REMOVAL
WARNING: Risk of injury to skin and eyes due to
scalding from hot coolant. Do not open the cooling
system unless the temperature is below 90ÉC
(194ÉF). Wear protective clothing and eye wear. Risk
of poisoning if coolant is swallowed. Store coolant
in proper and appropriately marked containers.
Fig. 4 COOLANT LEVEL SENSOR
1 - COOLANT LEVEL SENSOR
2 - COOLANT RESERVIOR
3 - ELECTRICAL CONNECTOR
Fig. 5 RADIATOR FAN
1 - VISCOUS CLUTCH
2 - COUNTERHOLDER
3 - CLUTCH BOLT
4 - FAN BOLT
5-FAN
7 - 14 ENGINEVA
(1) Disconnect the negative battery cable.
(2) Drain the cooling system.
(3) Record the location and snip the wire ties.
(4) Unscrew the engine block heater from the core
plug hole and remove (Fig. 6).
INSTALLATION
(1) Screw the block heater into the core hole (Fig.
6).
(2) Route the heater wiring harness away from
and interference and secure with wiring tie straps.
(3) Refill the cooling system.
(4) Connect the negative battery cable.
(5) Start the engine and inspect for leaks.
ENGINE COOLANT TEMP SEN-
SOR
DESCRIPTION
The ECM determines the operating temperature of
the engine by using the signal from the coolant tem-
perature sensor. The coolant temperature sensor has
a negative temperature coefficient (NTC) resistor
contained in the plastic housing. NTC means; the
higher the temperature, then the lower the resis-
tance. The ECM also uses the coolant temperature
sensor signal to calculate glow plug relay triggering.
If the coolant temperature sensor fails during opera-
tion, the ECM will switch on the cooling fan to pre-
vent engine overheating (A/C models only).
REMOVAL
WARNING: Risk of injury to skin and eyes from
scalding with hot coolant. Risk of poisoning from
swallowing coolant. Do not open cooling system
unless coolant temperature is below 90ÉC. Open
cap slowly to release pressure. Store coolant in
suitable and appropriately marked container. Wear
protective gloves, clothes and eye wear.
(1) Disconnect negative battery cable.
(2) Remove engine cover (Refer to 9 - ENGINE -
REMOVAL).
(3) Partailly drain coolant system (Refer to 7 -
COOLING/ENGINE/COOLANT - STANDARD PRO-
CEDURE).
(4) Unplug coolant temperature sensor electrical
connector.
NOTE: Capture any residual coolant that may flow.
(5) Remove coolant temperature sensor (Fig. 7).
INSTALLATION
WARNING: Risk of injury to skin and eyes from
scalding with hot coolant. Risk of poisoning from
swallowing coolant. Do not open cooling system
unless coolant temperature is below 90ÉC (194ÉF).
Open cap slowly to release pressure. store coolant
in suitable and appropriately marked container.
Wear protective gloves, clothes and eye wear.
(1) Position and install coolant temperature sensor
(Fig. 7).
(2) Connect coolant temperature sensor electrical
connector (Fig. 7).
Fig. 6 ENGINE BLOCK HEATER
1 - ENGINE BLOCK HEATER
2 - CORE PLUG
3 - ENGINE MOUNT
4 - WIRING TIE STRAPS
Fig. 7 ENGINE COOLANT TEMPERATURE SENSOR
1 - RETAINING CLAMP
2 - ENGINE COOLANT TEMPERATURE SENSOR
VAENGINE 7 - 15