oil temperature CHRYSLER VOYAGER 1996 Service Manual

LUBRICATION AND MAINTENANCE
CONTENTS
page page
GENERAL INFORMATION.................. 1
JUMP STARTING, HOISTING AND TOWING . . . 5MAINTENANCE SCHEDULES............... 2
GENERAL INFORMATION
INDEX
page page
GENERAL INFORMATION
ENGINE OIL Ð GASOLINE ENGINES........ 1
ENGINE OILÐDIESEL ENGINES............ 1FLUID CAPACITIES...................... 1
MANUAL TRANSMISSION FLUID
(A-558 and A-598 Models)................ 1
GENERAL INFORMATION
ENGINE OIL Ð GASOLINE ENGINES
Use only oils conforming to API (American Petro-
leum Institute) Quality SJ and Energy Conserving II,
or SH and Energy Conserving II, or ACEA A1±96.
SAE VISCOSITY GRADE
To assure of properly formulated engine oils, it is
recommended that SAE Grade 5W-30 engine oils that
meet Chrysler material standard MS-6395, be used.
SAE Grade 10W-30 oils are also acceptable when the
temperatures do not fall below 0ÉC. In areas where
these grades are not generally available, higher SAE
grades may be used.
Lubricants which have both an SAE grade number
and the proper API service classification shown on
the container should be used.
ENGINE OILÐDIESEL ENGINES
Use only Diesel Engine Oil meeting standardMIL-
2104Cor API ClassificationSG/CDorCCMC PD2.
SAE VISCOSITY GRADE
CAUTION: Low viscosity oils must have the proper
API quality or the CCMC G5 designation.
To assure of properly formulated engine oils, it is recom-
mended that SAE Grade 15W-40 engine oils that meet
Chrysler material standard MS-6395, be used. European
Grade 10W-40 oils are also acceptable.
Oils of the SAE 5W-30 or 10W-30 grade number
are preferred when minimum temperatures consis-
tently fall below -12ÉC.
MANUAL TRANSMISSION FLUID (A-558 and A-598
Models)
Use only SAE 10W-40 engine oils carrying the
European CCMC-G5 classification to fill the A-598
5±speed manual transmission.
FLUID CAPACITIES
Fuel Tank.............................76L
2.0L Gasoline Engine Oil with Filter........4.3L
2.5L VM Diesel Engine Oil With Filter......6.5L
2.0L Gasoline Engine Cooling System*.......6.0L
2.5L VM Diesel Engine Cooling System*....10.0 L
TransmissionÐ5-Speed Manual............2.2L
* Includes heater and coolant recovery tank filled
to Max level. Add 2.76L if equipped with Rear
Heater.
NS/GSLUBRICATION AND MAINTENANCE 0 - 1

MAINTENANCE SCHEDULES
INDEX
page page
GENERAL INFORMATION
MAINTENANCE SCHEDULE............... 2
MAINTENANCE SCHEDULEÐ
DIESEL ENGINE....................... 2SCHEDULEÐA (DIESEL).................. 2
SCHEDULEÐB (DIESEL).................. 3
UNSCHEDULED INSPECTION.............. 2
GENERAL INFORMATION
MAINTENANCE SCHEDULE
Refer to the 1998 GS Service Manual for Gasoline
Engine and non-engine related Maintenance Sched-
ules.
MAINTENANCE SCHEDULEÐDIESEL ENGINE
The following are engine related Maintenance
items which are unique to Diesel engine-equipped
vehicles. Refer to the 1998 GS Service Manual for
Gasoline Engine and non-engine related Maintenance
Schedules.
The service intervals are based on odometer read-
ings in kilometers. There are two maintenance sched-
ules that show proper service intervals. Use the
schedule that best describes the conditions the vehi-
cle is operated under.Schedule-Alists all the sched-
uled maintenance to be performed under normal
operating conditions.Schedule-Bis the schedule for
vehicles that are operated under one or more of the
following conditions:
²Day and night temperatures are below freezing.
²Stop and go driving.
²Long periods of engine idling.
²Driving in dusty conditions.
²Short trips of less than 5 miles.
²Operation at sustained high speeds during hot
weather above 32ÉC (90ÉF).
²Taxi, police or delivery service.
²Trailer towing.
UNSCHEDULED INSPECTION
At Each Stop for Fuel
²Check engine oil level, add as required.
²Check windshield washer solvent and add if
required.
Once a Month
²Check tire pressure and look for unusual wear
or damage.
²Inspect battery and clean and tighten terminals
as required.²Check fluid levels of coolant reservoir, brake
master cylinder, power steering and transaxle and
add as needed.
²Check all lights and all other electrical items for
correct operation.
²Check rubber seals on each side of the radiator
for proper fit.
At Each Oil Change
²Inspect exhaust system.
²Inspect brake hoses
²Inspect the CV joints and front suspension com-
ponents
²Rotate the tires at each oil change interval
shown on ScheduleÐA (7,500 miles) or every other
interval shown on ScheduleÐ B (6,000 miles).
²Check the coolant level, hoses, and clamps.
²If your mileage is less than 7,500 miles (12 000
km) yearly, replace the engine oil filter at each oil
change.
²Replace engine oil filter.
SCHEDULEÐA (DIESEL)
1 000 KM
²Change engine oil.
²Change engine oil filter.
²Check all fluid levels.
²Check correct torque, intake manifold mounting
nuts.
²Check correct torque, exhaust manifold mount-
ing nuts.
²Check correct torque, turbocharger mounting
nuts.
²Check correct torque, water manifold bolts.
10 000 KM
²Change engine oil.
²Change engine oil filter.
20 000 KM
²Change engine oil.
²Change engine oil filter.
²Replace air filter element.
0 - 2 LUBRICATION AND MAINTENANCENS/GS

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

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)

THERMOSTAT OPERATION
2.5 VM DIESEL
The engine cooling thermostats are 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 (Fig. 10). The
thermostat has a hole to bleed off air in the cooling
system during engine warm up. The thermostat
begins to open at 80É C62É (176É F64É).
PRESSURE/VENT CAP
WARNING: Engine coolant can reach temperatures
of 200É fahrenheit or greater. If the cooling system
is opened with coolant at a high temperature, hot
coolant can be forced out of the system under high
pressures, causing personal injury. Allow system to
cool down prior to removing the pressure cap.
The pressure/vent cap is secured to the coolant
tank neck by a means of a cam lock system. This cap
releases excess pressure at some point within a
range of 90-117 kPa (13- 17 psi) for gasoline engines,
and 110±124 kPa (16±18 psi) for diesel engines. The
actual pressure relief point (in pounds) is labeled on
top of the cap (Fig. 11).
The cooling system will operate at pressures
slightly above atmospheric pressure. This results in a
higher coolant boiling point allowing increased radi-
ator cooling capacity. The cap (Fig. 11) contains a
spring-loaded pressure relief valve. This valve opens
when system pressure reaches approximately 103
kPa (15 psi).
When the engine is cooling down, vacuum is
formed within the cooling system. To prevent collapse
of the radiator and coolant hoses from this vacuum, a
vacuum valve is used within the cap. This valve pre-
vents excessive pressure differences from occurring
between the closed cooling system and the atmo-
sphere. If the vacuum valve is stuck shut, the radia-
tor and/or cooling system hoses will collapse on cool-
down.
Fig. 7 Water PumpÐ2.0L Gasoline Engine
Fig. 8 Water PumpÐ2.0L Gasoline Engine
Fig. 9 Water PumpÐ2.5L VM Diesel
Fig. 10 Thermostat and Housing Ð 2.5L VM Diesel
7 - 4 COOLING SYSTEMNS/GS
DESCRIPTION AND OPERATION (Continued)

NOTE: Do not use any type of tool when tighten-
ing the cap. Hand tighten only (approximately 5 N´m
or 44 in. lbs.) torque.
COOLANT PERFORMANCE
ETHYLENE-GLYCOL MIXTURES
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 -37 deg. C (-35 deg. F). The anti-
freeze concentrationmust alwaysbe a minimum of
44 percent, 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 -67.7 deg. C (-90 deg. F). A
higher percentage will freeze at a warmer tempera-
ture.100 Percent Ethylene-GlycolÐShould 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
149 deg. C (300) deg. F). This temperature is hot
enough to melt plastic and soften solder. The
increased temperature can result in engine detona-
tion. In addition, 100 percent ethylene-glycol freezes
at 22 deg. C (-8 deg. F ).
Propylene-glycol FormulationsÐShould 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 -32 deg. C (-26 deg. F). 5 deg. C higher
than ethylene-glycol's freeze point. The boiling point
(protection against summer boil-over) of propylene-
glycol is 125 deg. C (257 deg.F)at96.5 kPa (14 psi),
compared to 128 deg. C (263 deg. F) for ethylene-gly-
col. Use of propylene-glycol can result in boil-over or
freeze-up in Chrysler vehicles, which are designed for
ethylene-glycol. Propylene glycol also has poorer heat
transfer characteristics than ethylene glycol. This
can increase cylinder head temperatures under cer-
tain conditions.
Propylene-glycol/Ethylene-glycol MixturesÐShould 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.
BELT TENSION
Correct accessory drive belt tension is required to
be sure of optimum performance of belt driven engine
accessories. If specified tension is not maintained,
belt slippage may cause; engine overheating, lack of
power steering assist, loss of air conditioning capac-
ity, reduced generator output rate and greatly
reduced belt life.
Fig. 11 Coolant Tank Pressure/Vent Cap
NS/GSCOOLING SYSTEM 7 - 5
DESCRIPTION AND OPERATION (Continued)

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)

BATTERY OPEN CIRCUIT VOLTAGE TEST
An open circuit voltage no load test shows the
state of charge of a battery and whether it is ready
for a load test at 50 percent of the battery's cold
crank rating. Refer to Battery Load Test. If a battery
has open circuit voltage reading of 12.4 volts or
greater, and will not pass the load test, replace the
battery because it is defective. To test open circuit
voltage, perform the following operation.
(1) Remove both battery cables, negative cable
first. Battery top, cables and posts should be clean. If
green dot is not visible in indicator, charge the bat-
tery. Refer to Battery Charging Procedures.
(2) Connect a Volt/Ammeter/Load tester to the bat-
tery posts (Fig. 6). Rotate the load control knob of the
Carbon pile rheostat to apply a 300 amp load. Apply
this load for 15 seconds to remove the surface charge
from the battery, and return the control knob to off
(Fig. 7).
(3) Allow the battery to stabilize for 2 minutes,
and then verify the open circuit voltage (Fig. 9).
(4) This voltage reading will approximate the state
of charge of the battery. It will not reveal battery
cranking capacity. Refer to Battery Open Circuit
Voltage table.
SERVICE PROCEDURES
BATTERY CHARGING
WARNING: DO NOT CHARGE A BATTERY THAT
HAS EXCESSIVELY LOW ELECTROLYTE LEVEL.
BATTERY MAY SPARK INTERNALLY AND
EXPLODE. EXPLOSIVE GASES FORM OVER THE
BATTERY. DO NOT SMOKE, USE FLAME, OR CRE-
ATE SPARKS NEAR BATTERY. DO NOT ASSIST
BOOST OR CHARGE A FROZEN BATTERY. BAT-
TERY CASING MAY FRACTURE. BATTERY ACID IS
POISON, AND MAY CAUSE SEVERE BURNS. BAT-
TERIES CONTAIN SULFURIC ACID. AVOID CON-
TACT WITH SKIN, EYES, OR CLOTHING. IN THE
EVENT OF CONTACT, FLUSH WITH WATER AND
CALL PHYSICIAN IMMEDIATELY. KEEP OUT OF
REACH OF CHILDREN.
CAUTION: Disconnect the battery NEGATIVE cable
first. (Fig. 4) before charging battery to avoid dam-
age to electrical systems. Do not exceed 16.0 volts
while charging battery. Refer to the instructions
supplied with charging equipment
NOTE: The battery cannot be refilled with water, it
must be replaced.
A battery is considered fully charged when it will
meet all the following requirements.
²It has an open circuit voltage charge of at least
12.4 volts.
²It passes the 15 second load test, refer to the
Load Test Temperature chart.
²The built in test indicator dot is GREEN (Fig.
1).
Battery electrolyte will bubble inside of battery
case while being charged properly. If the electrolyte
boils violently, or is discharged from the vent holes
while charging, immediately reduce charging rate or
turn off charger. Evaluate battery condition. Battery
damage may occur if charging is excessive.
Some battery chargers are equipped with polarity
sensing devices to protect the charger or battery from
being damaged if improperly connected. If the bat-
tery state of charge is too low for the polarity sensor
to detect, the sensor must be bypassed for charger to
operate. Refer to operating instructions provided
with battery charger being used.
CAUTION: Charge battery until test indicator
appears green. Do not overcharge.
It may be necessary to jiggle the battery or vehicle
to bring the green dot in the test indicator into view.
Fig. 9 Testing Open Circuit Voltage
BATTERY OPEN CIRCUIT VOLTAGE
Open Circuit VoltsCharge Per-
centage
11.7 volts or less 0%
12.0 volts 25%
12.2 volts 50%
12.4 volts 75%
12.6 volts or more 100%
8A - 6 BATTERYNS
DIAGNOSIS AND TESTING (Continued)