radiator cap CHRYSLER VOYAGER 2001 Owner's Manual

STANDARD PROCEDURE - COOLANT LEVEL
CHECK
NOTE: Do not remove pressure/vent cap for routine
coolant level inspections.
The coolant reserve system provides a quick visual
method for determining the coolant level without
removing the pressure/vent cap.With the engine
cold and not running,simply observe the level of
the coolant in the coolant recovery pressure container
(Fig. 2). The coolant level should be between the MIN
and MAX marks.
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM
Remove pressure/vent cap (Fig. 1) and fill system,
using a 50/50 mix of MopartAntifreeze/Coolant, 5
Year/100,000 Mile Formula and distilled water.
Continue filling system until full.Be careful not
to spill coolant on drive belts or the generator.
Fill coolant recovery pressure container (Fig. 1) to
at least the MAX mark with 50/50 solution. It may
be necessary to add coolant to the coolant recovery
pressure container 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.
STANDARD PROCEDURE - DRAINING COOLING
SYSTEM
WARNING: DO NOT REMOVE OR LOOSEN THE
COOLANT PRESSURE/VENT CAP, CYLINDER
BLOCK DRAIN PLUGS, OR THE DRAINCOCK WHEN
THE SYSTEM IS HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM THE COOLANT
CAN OCCUR.
(1)Without removing pressure/vent cap and
with system not under pressure, open the drain-
cock. The draincock is located on the lower right side
of radiator (Fig. 3).
(2) After the coolant recovery pressure container is
empty, then remove coolant pressure/vent cap.
Fig. 1 UNDERHOOD FLUID FILL LOCATIONS
1 - COOLANT PRESSURE/VENT CAP
2 - BRAKE MASTER CYLINDER
3 - INTELLIGENT POWER MODULE
4 - BATTERY
5 - COOLANT RECOVERY PRESSURE CONTAINER6 - OIL DIPSTICK
7 - WINDSHIELD SOLVENT RESEVOIR
8 - AIR FILTER HOUSING
9 - ENGINE OIL FILL CAP
7a - 16 ENGINERG
COOLANT (Continued)

COOLANT RECOVERY PRESS
CONTAINER
DESCRIPTION
The coolant recovery pressure container is
mounted in the engine compartment next to the bat-
tery. The coolant recovery pressure container is made
of plastic (Fig. 4).
OPERATION
The coolant recovery pressure container works
with the pressure/vent cap to use thermal expansion
and contraction of the coolant to keep the coolant
free of trapped air. Provides a convenient and safe
method for checking coolant level and adjusting level
at atmospheric pressure without removing the pres-
sure/vent cap. It also provides some reserve coolant
to cover deaeration, evaporation, or boiling losses.
Fig. 2 COOLANT RECOVERY PRESSURE
CONTAINER LOCATION
1 - PRESSURE/VENT CAP
2 - BRAKE MASTER CYLINDER
3 - BATTERY
4 - BATTERY SHIELD
5 - COOLANT RECOVERY PRESSURE CONTAINER RETAINING
CLIP
6 - ENGINE COVER
7 - COOLANT RECOVERY PRESSURE CONTAINER
Fig. 3 DRAINCOCK LOCATION
1 - RADIATOR
2 - DRAINCOCK
3 - LOWER RADIATOR SUPPORT
4 - ELECTRIC COOLING FAN
Fig. 4 COOLANT RECOVERY PRESSURE
CONTAINER LOCATION
1 - PRESSURE/VENT CAP
2 - BRAKE MASTER CYLINDER
3 - BATTERY
4 - BATTERY SHIELD
5 - COOLANT RECOVERY PRESSURE CONTAINER RETAINING
CLIP
6 - ENGINE COVER
7 - COOLANT RECOVERY PRESSURE CONTAINER
RGENGINE7a-17
COOLANT (Continued)

REMOVAL
(1) Drain cooling system below level of coolant
recovery pressure bottle. (Refer to 7 - COOLING/EN-
GINE/COOLANT - STANDARD PROCEDURE)
(2) Disconnect coolant bypass and overflow hoses
from coolant recovery pressure container (Fig. 6).
(3) Unclip the coolant recovery pressure container
retaining clip (Fig. 5).
(4) Raise coolant recovery pressure container from
mounting bracket and disconnect coolant hose from
bottom of container (Fig. 6).
(5) Remove coolant recovery pressure bottle.
INSTALLATION
(1) Connect coolant hose at bottom of coolant
recovery pressure container (Fig. 6) and install in
mounting bracket.
(2) Connect coolant recovery pressure container
retaining clip (Fig. 5).
(3) Connect coolant bypass and overflow hoses to
coolant recovery pressure container.
(4) Refill cooling system. (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE)
Fig. 7 COOLANT TEMPERATURE SENSOR
LOCATION
1 - EGR SOLENOID
2 - UPPER RADIATOR HOSE
3 - COOLANT TEMPERATURE SENSOR
4 - INTAKE MANIFOLD INLET
5 - INTAKE MANIFOLD/CYLINDER HEAD COVER
Fig. 5 COOLANT RECOVERY PRESSURE
CONTAINER LOCATION
1 - PRESSURE/VENT CAP
2 - BRAKE MASTER CYLINDER
3 - BATTERY
4 - BATTERY SHIELD
5 - COOLANT RECOVERY PRESSURE CONTAINER RETAINING
CLIP
6 - ENGINE COVER
7 - COOLANT RECOVERY PRESSURE CONTAINER
Fig. 6 COOLANT RECOVERY PRESSURE
CONTAINER
1 - COOLANT RECOVERY PRESSURE CONTAINER
2 - COOLANT BYPASS HOSE
3 - OUTLET HOSE
4 - PRESSURE/VENT CAP
7a - 18 ENGINERG
COOLANT RECOVERY PRESS CONTAINER (Continued)

ENGINE COOLANT TEMP
SENSOR
DESCRIPTION
The engine coolant temperature sensor threads
into a coolant passage in the cylinder head (Fig. 7).
New sensors have sealant applied to the threads.
OPERATION
The coolant temperature (ECT) sensor is a nega-
tive temperature coefficient (NTC) thermistor (resis-
tance varies inversley with temperature). This means
at cold tempertures its resistance is high so the volt-
age signal will be high. As coolant temperture
increases, resistance decreases and the signal voltage
will be low. This allows the sensor to provide an ana-
log voltage signal to the ECM.
REMOVAL
WARNING: DO NOT REMOVE OR LOOSEN THE
COOLANT PRESSURE/VENT CAP, CYLINDER
BLOCK DRAIN PLUGS, OR THE DRAINCOCK WHEN
THE SYSTEM IS HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM THE COOLANT
CAN OCCUR.
(1) Drain the cooling system. (Refer to 7 - COOL-
ING/ENGINE/COOLANT - STANDARD PROCE-
DURE).
(2) Disconnect coolant temperature sensor electri-
cal connector (Fig. 8).
(3) Remove coolant temperature sensor from cylin-
der head (Fig. 8).
INSTALLATION
(1) Install coolant temperature sensor in cylinder
head (Fig. 8).
(2) Connect coolant temperature sensor electrical
connector (Fig. 8).
(3) Refill the cooling system. (Refer to 7 - COOL-
ING/ENGINE/COOLANT - STANDARD PROCE-
DURE).
(4) Connect the negative battery cable.
ENGINE COOLANT
THERMOSTAT
DESCRIPTION
A pellet-type thermostat controls the operating
temperature of the engine by controlling the amount
of coolant flow to the radiator (Fig. 9).
OPERATION
The thermostat starts to open at 80ÉC (176ÉF).
Above this temperature, coolant is allowed to flow to
the radiator. This provides quicker engine warmup
and overall temperature control.
The same thermostat is used for winter and sum-
mer seasons. An engine should not be operated with-
out a thermostat, except for servicing or testing.
Operating without a thermostat causes other prob-
lems. These are: longer engine warmup time, unreli-
able warmup performance, increased exhaust
emissions and crankcase condensation. This conden-
sation can result in sludge formation.
REMOVAL
NOTE: The thermostat is not serviced separately.
The thermostat and housing must be replaced as
an assembly.
(1) Disconnect negative battery cable.
(2) Drain cooling system (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(3) Remove front wiper unit to gain access to ther-
mostat housing(Refer to 8 - ELECTRICAL/WIPERS/
WASHERS/WIPER MODULE - REMOVAL).
Fig. 8 COOLANT TEMPERATURE SENSOR
LOCATION
1 - EGR SOLENOID
2 - UPPER RADIATOR HOSE
3 - COOLANT TEMPERATURE SENSOR
4 - INTAKE MANIFOLD INLET
5 - INTAKE MANIFOLD/CYLINDER HEAD COVER
RGENGINE7a-19

(4) Disconnect upper radiator hose adapter tube,
water pump hose, and EGR hose at thermostat hous-
ing.
(5) Remove both thermostat housing attaching
bolts and housing (Fig. 10).
INSTALLATION
(1) Install thermostat housing, gasket, and retain-
ing bolts (Fig. 10). Torque bolts to 27.5N´m.
(2) Connect upper radiator hose adapter tube,
water pump hose, and EGR cooler hose to thermostat
housing.
(3) Install front wiper unit (Refer to 8 - ELECTRI-
CAL/WIPERS/WASHERS/WIPER MODULE -
INSTALLATION).
(4) Refill cooling system (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(5) Connect negative battery cable.
RADIATOR
DESCRIPTION
The radiator is a cross-flow type (horizontal tubes)
with design features that provide greater strength
along with sufficient heat transfer capabilities tokeep the engine satisfactorily cooled. The radiator
has plastic side tanks and aluminum cooling tubes.
OPERATION
The radiator functions as a heat exchanger, using
air flow across the exterior of the radiator tubes. This
heat is then transferred from the coolant and into
the passing air.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove radiator upper crossmember support.
(Refer to 23 - BODY/EXTERIOR/GRILLE OPENING
REINFORCEMENT - REMOVAL).
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK PLUG OR THE RADIATOR DRAINCOCK
WITH THE SYSTEM HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM COOLANT CAN
OCCUR.
(3) Drain the cooling system (Refer to 7 - COOL-
ING/ENGINE/COOLANT - STANDARD PROCE-
DURE).
Fig. 9 THERMOSTAT HOUSING LOCATION
1 - CYLINDER HEAD COVER
2 - THERMOSTAT HOUSING
3 - AIR BLEED
4 - WATER PUMP
5 - WATER PUMP HOUSING TO THERMOSTAT HOUSING
BYPASS HOSE
6 - E G R VA LV E
Fig. 10 THERMOSTAT HOUSING ASSEMBLY
1 - THERMOSTAT HOUSING GASKET
2 - THERMOSTAT HOUSING
3 - RETAINING BOLTS
4 - CYLINDER HEAD
5 - CYLINDER HEAD COVER/INTAKE MANIFOLD
7a - 20 ENGINERG
ENGINE COOLANT THERMOSTAT (Continued)

RADIATOR PRESSURE CAP
DESCRIPTION
The cooling system pressure cap is located on the
radiator. The cap construction includes; stainless
steel swivel top, rubber seals, and retainer, main
spring, and a spring loaded valve (Fig. 19).
OPERATION
The cooling system is equipped with a pressure cap
that releases excessive pressure; maintaining a range
of 97-124 kPa (14-18 psi).
The cooling system will operate at higher than
atmospheric pressure. The higher pressure raises the
coolant boiling point thus, allowing increased radia-
tor cooling capacity.
There is also a vent valve in the center of the cap.
This valve also opens when coolant is cooling and
contracting, allowing the coolant to return to cooling
system from coolant reserve system tank by vacuum
through a connecting hose.If valve is stuck shut,
or the coolant recovery hose is pinched, the
radiator hoses will be collapsed on cool down.
Clean the vent valve (Fig. 19) and inspect cool-
ant recovery hose routing, to ensure proper
sealing when boiling point is reached.
The gasket in the cap seals the filler neck, so that
vacuum can be maintained, allowing coolant to be
drawn back into the radiator from the reserve tank.
If the gasket is dirty or damaged, a vacuum
may not be achieved, resulting is loss of coolant
and eventual overheating due to low coolant
level in radiator and engine.
Fig. 17 WATER PUMP ASSEMBLY
1 - WATER PUMP HOUSING STUDS
2 - WATER PUMP
3 - RETAINING NUTS
4 - OIL COOLER RETAINING STUD
5 - OIL COOLER TO ENGINE BLOCK RETAINING BOLT
6 - OIL COOLER COOLANT HOSE
7 - ENGINE BLOCK
Fig. 18 WATER PUMP HOUSING O-RING
1 - WATER PUMP
2 - WATER PUMP HOUSING O-RING
3 - WATER PUMP HOUSING
Fig. 19 Cooling System Pressure Cap Filler Neck
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - PRESSURE BOTTLE
8 - FILLER NECK
7a - 24 ENGINERG
WATER PUMP (Continued)

DIAGNOSIS AND TESTING - COOLING SYSTEM
PRESSURE CAP
Dip the pressure cap in water. Clean any deposits
off the vent valve or its seat and apply cap to end of
the Pressure Cap Test Adaptor that is included with
the Cooling System Tester 7700. 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 the pressure cap.
CAUTION: The Cooling System Tester Tool is very
sensitive to small air leaks that will not cause cool-
ing system problems. A pressure cap that does not
have a history 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.
If the pressure cap tests properly while positioned
on Cooling System Tester (Fig. 20), but will not hold
pressure or vacuum when positioned on the filler
neck. Inspect the filler neck and cap top gasket for
irregularities that may prevent the cap from sealing
properly.
DIAGNOSIS AND TESTING - PRESSURE
RELIEF TEST
The pressure cap upper gasket (seal) pressure
relief can be checked by removing the overflow hose
at the radiator filler neck nipple (Fig. 21). 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.
(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 WITH-
OUT PUSHING DOWN ROTATE COUNTERCLOCK-
WISE TO THE FIRST STOP. ALLOW FLUIDS TO
ESCAPE THROUGH THE OVERFLOW TUBE AND
WHEN THE SYSTEM STOPS PUSHING COOLANT
AND STEAM INTO THE CRS TANK AND PRESSURE
DROPS PUSH DOWN AND REMOVE THE CAP COM-
PLETELY. SQUEEZING THE RADIATOR INLET HOSE
WITH A SHOP TOWEL (TO CHECK PRESSURE)
BEFORE AND AFTER TURNING TO THE FIRST
STOP IS RECOMMENDED.
CLEANING
Use only a mild soap to clean the pressure cap.
Fig. 20 Testing Cooling System Pressure Cap
1 - PRESSURE CAP
2 - PRESSURE TESTER
Fig. 21 Radiator Pressure Cap Filler Neck
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - PRESSURE BOTTLE
8 - FILLER NECK
RGENGINE7a-25
RADIATOR PRESSURE CAP (Continued)

INSPECTION
Hold the cap in your hand,top side up(Fig. 21).
The vent valve at the bottom of the cap should open.
If the rubber gasket has swollen, preventing the
valve from opening, replace the cap.
Hold the cleaned cap in your hand,upside down.
If any light can be seen between vent valve and the
rubber gasket, replace the cap.Do not use a
replacement cap that has a spring to hold the
vent shut.
A replacement cap must be of the type designed for
coolant reserve systems. This design ensures coolant
return to the radiator.
RADIATOR FAN
DESCRIPTION
The dual radiator fans are mounted to the back
side of the radiator (Fig. 22). The radiator fan consist
of the fan blade, electric motor and a support shroud
which are all serviced as an assembly.
OPERATION
RADIATOR FAN OPERATION CHART
COOLANT TEMPERATURE A/C PRESSURE
Fan Operation
Speeds:Initial Max Initial Max
Fan On: 104ÉC (220ÉF) 110ÉC (230ÉF) Fan
Speed Duty-Cycles
(Ramps-up) from
30% to 99%1,724 Kpa (250 psi) 2,068 Kpa (300 psi)
Fan Speed
Duty-Cycles
(Ramps-up) from
30% to 99%
Fan Off: 101ÉC (214ÉF) Fan Speed
Duty-Cycles
(Ramps-down) from
99% to 30%1,710 Kpa (248 psi) Fan Speed
Duty-Cycles
(Ramps-down) from
99% to 30%
DIAGNOSIS AND TESTING - RADIATOR FAN MOTOR
RADIATOR FAN DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
NOISY RADIATOR FAN 1. Fan blade loose. 1. Replace fan assembly. (Refer to
7 - COOLING/ENGINE/RADIATOR
FAN - REMOVAL)
2. Fan blade striking a surrounding
object.2. Locate point of fan blade contact
and repair as necessary.
3. Air obstructions at radiator or A/C
condenser.3. Remove obstructions and/or
clean debris.
4. Electric fan motor defective. 4. Replace fan assembly. (Refer to
7 - COOLING/ENGINE/RADIATOR
FAN - REMOVAL)
ELECTRIC FAN MOTOR DOES
NOT OPERATE1. Fan relay, powertrain control
module (PCM), coolant temperature
sensor, or wiring defective.1. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
2. Defective A/C pressure
transducer.2. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
7a - 26 ENGINERG
RADIATOR PRESSURE CAP (Continued)

OPERATION - HOSE CLAMPS
The spring type hose clamp applies constant ten-
sion on a hose connection. To remove a spring type
hose clamp, use Special Tool 6094 or equivalent, con-
stant tension clamp pliers (Fig. 24) to compress the
hose clamp.
RADIATOR FAN RELAY
DESCRIPTION
The low and high speed fan relays are mounted to
the upper radiator support above the charge air
cooler (Fig. 25).
OPERATION
The cooling system uses two fans. Both fans oper-
ate at two different speeds, low and high. Depending
on engine coolant temperature and A/C system high
side pressure, the fans operate at either low or high.
The ignition switch supplies voltage to the coil side of
the relay. When the ECM grounds the coil side of the
relay, the contacts close and the battery supplies
power to the fans.
COOLANT SYSTEM HOSES
REMOVAL - UPPER RADIATOR HOSE
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.(1) Remove engine cover (Refer to 9 - ENGINE -
REMOVAL).
(2) Drain cooling system (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(3) Remove upper radiator hose (Fig. 26).
REMOVAL - LOWER RADIATOR HOSE
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.
(1) Drain cooling system (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(2) Remove lower radiator hose (Fig. 26).
REMOVAL - COOLANT BYPASS HOSE
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.
(1) Drain cooling system (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(2) Remove the coolant bypass hose (Fig. 26).
Fig. 24 Hose Clamp Tool
1 - HOSE CLAMP TOOL 6094
2 - HOSE CLAMP
Fig. 25 RELAY LOCATIONS
1 - GLOW PLUG RELAY
2 - UPPER RADIATOR SUPPORT
3 - CHARGE AIR COOLER OUTLET HOSE
4 - RADIATOR FAN RELAYS
5 - UPPER RADIATOR HOSE
6 - EGR SOLENOID
7a - 28 ENGINERG
HOSE CLAMPS (Continued)

ENGINE 2.4L
DESCRIPTION
The 2.4 Liter (148 cu. in.) in-line four cylinder
engine is a double over head camshaft with hydraulic
lifters and four valve per cylinder design. The engine
is free-wheeling; meaning it has provisions for piston-
to-valve clearance. However valve-to-valve interfer-
ence can occur, if camshafts are rotated
independently.
The cylinders are numbered from front of the
engine to the rear. The firing order is 1±3±4±2.
The engine identification number is located on the
rear of the cylinder block (Fig. 1).
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).
²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss.
WARNING: DO NOT REMOVE THE RADIATOR CAP
WITH THE SYSTEM HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM COOLANT CAN
OCCUR.
Check the coolant level and fill as required. DO
NOT install the radiator cap.
Start and operate the engine until it attains nor-
mal operating temperature, then turn the engine
OFF.
Clean spark plug recesses with compressed air.
Remove the spark plugs.
Remove the oil filler cap.Remove the air cleaner.
Calibrate the tester according to the manufactur-
er's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1,379
kPa (200 psi) maximum, with 552 kPa (80 psi) rec-
ommended.
Perform the test procedures on each cylinder
according to the tester manufacturer's instructions.
While testing, listen for pressurized air escaping
through the throttle body, tailpipe and oil filler cap
opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage per cylinder.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder.
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Check engine oil level and add oil if necessary.
(2) Drive the vehicle until engine reaches normal
operating temperature. Select a route free from traf-
fic and other forms of congestion, observe all traffic
laws, and accelerate through the gears several times
briskly.
(3) Remove all spark plugs from engine. As spark
plugs are being removed, check electrodes for abnor-
mal firing indicators fouled, hot, oily, etc. Record cyl-
inder number of spark plug for future reference.
(4) Disconnect the ignition coil electrical connector.
(5) Be sure throttle blade is fully open during the
compression check.
(6) Insert compression gage adaptor Special Tool
8116 or the equivalent, into the #1 spark plug hole in
cylinder head. Connect the 0±500 psi (Blue) pressure
transducer with cable adaptors to the DRBIIIt.
(7) Crank engine until maximum pressure is
reached on gage. Record this pressure as #1 cylinder
pressure.
(8) Repeat the previous step for all remaining cyl-
inders.
(9) Compression should not be less than 689 kPa
(100 psi) and not vary more than 25 percent from cyl-
inder to cylinder.
(10) If one or more cylinders have abnormally low
compression pressures, repeat the compression test.
(11) If the same cylinder or cylinders repeat an
abnormally low reading on the second compression
test, it could indicate the existence of a problem in
Fig. 1 Engine Identification
1 - ENGINE IDENTIFICATION LOCATION
RSENGINE 2.4L9-3