Page 848 of 1500
ON-VEHICLE SERVICE
HEATER, AIR CONDITIONING AND VENTILATION55-147
TEST PROCEDURES
1. Select a quiet area for testing.
2. Duplicate problem (customer complaint) as much as
possible.
3. Judge if the noise is abnormal (ie. it is important to
understand the characteristics of the vehicle and its normal
state to judge what is abnormal) - Compare with similar
vehicle if necessary.
4. Detail what and how noise occurs.
5. Find the noise source and verify its transmission by isolating
the subject part from the vehicle.
6. Repair the problem.
7. Explain and report your findings.
DETAILS OF A/C NOISE
POSSIBLE CAUSES, CHECKS AND REPAIRS
NOISE DESCRIPTION WHEN IT OCCURS SOURCE OF NOISE
Rumbling (Bearing noise) With A/C On or Off Magnetic clutch, idler pulley
Clang-Clack noise When compressor is engaged Magnetic clutch operation
Squawking (Belt sliding noise) When compressor is engaged V-belt
Whistling or Whooping noise Immediately after the A/C is
engaged.Expansion valve
Hissing or swishing noise When A/C is engaged, but
decreases as flow is stable Refrigerant flow
Rattling (Internal compressor) When compressor is operating Compressor internal part
Wooing (Resonant noise) With A/C On, occurs at certain
speed.Resonance of accessories
Cooing (Discharge pulsation
noise)With A/C On or Off Resonating noise with the vehicle
body
NOISE DESCRIPTION POSSIBLE CAUSE CHECK REPAIR
Rumbling (Bearing
noise)Bearing damage in rotor Manual rotation of bearing Replace compressor
Rotor slipping on boss Wear on compressor boss
surfaceReplace compressor
Bearing damage in pulley Check alignment between
pulleysReplace compressor
Clang-Clack noise Hub to stator misaligned Wear on inner clutch face Replace compressor
Gap between clutch
surface is too largeCheck Air gap is within
specificationReplace compressor
Squawking (Belt sliding
noise)Oil/water between the belt
and rotor surfaceOil and water
contaminationClean
Low belt tension Belt tension Reset or Replace belt and
set tension to correct
specification
Whistling or Whooping
noiseVibration of expansion
valveExpansion valve Replace TX valve
Page 865 of 1500
Page 866 of 1500
COMPRESSOR ASSEMBLY AND DRIVE BELT
HEATER, AIR CONDITIONING AND VENTILATION55-165
REMOVAL SERVICE POINTS
.
<> FLEXIBLE SUCTION HOSE AND FLEXIBLE
DISCHARGE HOSE DISCONNECTION
As the compressor oil and receiver are highly moisture
absorbent, use a non-porous material to plug the hose and
nipples.
To prevent the entry of dust or other foreign bodies, plug the
dismantled hoses and compressor nipples.
.
<> COMPRESSOR REMOVAL
Take care not to spill any compressor oil when removing the
compressor.
INSTALLATION SERVICE POINT
.
>>A<< FLEXIBLE SUCTION HOSE CONNECTION
To prevent mis-alignment of suction hose to bracket use the
folowing assembly procedure.
1. Insert hoseconnector into compressor and hand start bolt.
2. Assemble P-clip to hose and suction hose bracket. Tighten
bolt.
3. Tighten bolt between compressor and hose connector.
.
>>B<< COMPRESSOR INSTALLATION
If a new compressor is installed, first adjust the amount of oil
according to the procedures described below, and then install
the compressor.
1. Measure the amount (X ml) of oil within the removed
compressor.
2. Drain (from the new compressor) the amount of oil
calculated according to the following formula, and then
install the new compressor.
New compressor oil amount = 140 ml
140 ml
X ml = Y ml
NOTE: Y ml indicates the amount of oil in the refrigerant line,
the condenser, the evaporator, etc.
NOTE: When replacing the following parts at the same times as
the compressor, subtract the rated oil amount of each part from
Y ml and discharge from the new compressor.
Compressor oil: ND Oil 8
Quantity:
Evaporator: 40 ml
Condenser: 40 ml
Receiver: 40 ml
Page 867 of 1500
COMPRESSOR ASSEMBLY AND DRIVE BELT
HEATER, AIR CONDITIONING AND VENTILATION55-166
INSPECTIONM1552014301083
COMPRESSOR AIR CONDITIONING
COMPRESSOR CLUTCH OPERATION CHECK
Connect the compressor connector terminal to the battery posi-
tive (+) terminal and ground the battery’s negative (-) terminal
to the compressor unit. At that time, the air conditioning com-
pressor clutch should make a definite operating sound.
.
AIR GAP ADJUSTMENT
Check whether or not the air gap of the clutch is within the stan-
dard value.
Standard value:
0.35
0.60mm
NOTE: If there is a deviation of the air gap from the standard
value, assess the operation of the clutch and replace the com-
pressor assembly as required.
Page 910 of 1500
HOW TO DIAGNOSE
GENERAL 00E-9
CABLES AND WIRES CHECKM1001005100041
1. Check connections for looseness, rust, and stains.
2. Check terminals and wires for corrosion.
3. Check terminals and wires for open circuit or impending
open circuit.
4. Check wire insulation and coating for damage, cracks, and
wear.
5. Check conductive parts of terminals for contact with other
metallic parts (vehicle body and other parts).
6. Check grounding parts to verify that there is complete
continuity between attaching bolt(s) and vehicle body.
7. Check for incorrect wiring.
8. Check that harnesses are secured to prevent contact with
sharp edges and corners or hot parts (exhaust manifold,
pipe, etc.).
9. Check that harnesses are secured firmly to provide enough
clearance from the fan pulley, fan belt, and other rotating or
moving parts.
10.Check that the harnesses between fixed parts (such as the
vehicle body) and vibrating parts (such as the engine) are
long enough to allow for vibration and movement.
BATTERY HANDLINGM1001005200048
Battery posts, terminals and related accessories con-
tain lead and lead compounds. WASH HANDS AFTER
HANDLING.
When checking or servicing does not require power from the
vehicle battery, be sure to disconnect the cable from the battery
(
) terminal. This will prevent problems that could be caused by
a short circuit. Disconnect the (
) battery terminal first and
reconnect it last.
GENERAL ELECTRICAL SYSTEM CHECKM1001005300045
A circuit consists of the power supply, switch, relay, load,
ground, etc. There are various methods to check a circuit
including an overall check, voltage check, short-circuit check,
and continuity check. Each of the methods briefly described
below applies only to circuits similar to the illustration.
Page 917 of 1500
GENERAL DESCRIPTION
ENGINE COOLING14-2
GENERAL DESCRIPTIONM1141000100401
The cooling system is designed to keep every
part of the engine at appropriate temperature in
whatever condition the engine may be operated.
The cooling method is of the water-cooled, pres-
sure forced circulation type in which the water
pump pressurizes coolant and circulates it
throughout the engine. If the coolant temperature exceeds the prescribed temperature, the thermo-
stat opens to circulate the coolant through the
radiator as well so that the heat absorbed by the
coolant may be radiated into the air. The water
pump is of the centrifugal type and is driven by
the drive belt from the crankshaft. The radiator is
the corrugated fin, down flow type.
SPECIAL TOOLM1141000600279
ENGINE COOLING DIAGNOSIS
INTRODUCTIONM1141005300347
The system cools the engine so that it does not over-
heat and maintains the engine at an optimum tem-
perature. The system components are the radiator,
water pump, thermostat, condenser and fan assem-
blies. Possible faults include low coolant, contamina-
tion, belt loosening and component damage.
TROUBLESHOOTING STRATEGYM1141005200340
Use these steps to plan your diagnostic strategy. If
you follow them carefully, you will be sure to find
most of the engine cooling faults.
1. Gather information from the customer.2. Verify that the condition described by the
customer exists.
3. Find and repair the malfunction by following the
SYMPTOM CHART.
4. Verify that the malfunction is eliminated. TOOL TOOL NUMBER AND
NAMESUPERSESSION APPLICATION
MB991871
LLC changerGeneral service tool Coolant refilling
Page 919 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-4
INSPECTION PROCEDURE 2: Engine Overheating
DIAGNOSIS
STEP 1. Remove the radiator cap and check for coolant
contamination.
Q: Is the coolant contaminated with rust and oil?
YES : Replace it. Refer to P.14-27.
NO : There is no action to be taken. Go to Step 2.
STEP 2. Check the radiator cap valve opening pressure.
NOTE: Be sure that the cap is clean before testing. Rust or
other foreign material on the cap seal will cause an improper
reading.
(1) Use a cap adapter to attach the cap to the tester.
(2) Increase the pressure until the gauge indicator stops
moving.
Minimum limit: 83 kPa (12 psi)
Standard value: 93
123 kPa (14 18 psi)
Q: Does the reading remain at or above the minimum limit?
YES : Go to Step 3.
NO : Replace the radiator cap. Then go to Step 5.
STEP 3. Check thermostat operation.
Refer to 38.
Q: Does the thermostat operate correctly?
YES : Go to Step 4.
NO : Replace the thermostat, then go to Step 5.
STEP 4. Check the drive belt for slippage or damage.
Refer to GROUP 00, Maintenance Service
Drive Belts
(Check Condition). <3.8L Engine>39 .
Q: Is the drive belt loose or damaged?
YES : Adjust or replace the drive belt, then go to Step 5.
NO : There is no action to be taken.
STEP 5. Retest the system.
Check the engine coolant temperature.
Q: Is the engine coolant temperature abnormally high?
YES : Return to Step 2.
NO : The procedure is complete.
Page 954 of 1500
WATE R P U M P
ENGINE COOLING14-39
WAT E R P U M P
REMOVAL AND INSTALLATIONM1141002700498
INSTALLATION SERVICE POINT
.
>>A<< O-RING INSTALLATION
Do not let the O-ring get contaminated with grease or
engine oil.
Fit the O-ring into the groove of the water pipe ends, and apply
water or coolant to the circumference of the O-ring and the pipe
bores to insert the pipe assembly.
Pre-removal and Post-installation Operation
Engine Coolant Draining and Refilling (Refer to 27).
Timing Belt Removal and Installation (Refer to GROUP
11C, Timing Belt 11A-46).
Crankshaft Position Sensor Removal and Installation
(Refer to GROUP 16, Crankshaft Position Sensor 35).
REMOVAL STEPS
1. WATER PUMP BRACKET
2. WATER PUMP3. WATER PUMP GASKET
>>A<<4. O-RINGREMOVAL STEPS (Continued)
