14-1
GROUP 14
ENGINE COOLING
CONTENTS
GENERAL INFORMATION . . . . . . . .14-2
SERVICE SPECIFICATIONS . . . . . . .14-2
LUBRICANT . . . . . . . . . . . . . . . . . . . .14-2
SEALANTS . . . . . . . . . . . . . . . . . . . .14-3
SPECIAL TOOLS . . . . . . . . . . . . . . . .14-3
TROUBLESHOOTING . . . . . . . . . . . .14-5
INSPECTION CHART FOR TROUBLE
SYMPTOMS . . . . . . . . . . . . . . . . . . . . . . . . 14-5
INSPECTION PROCEDURE FOR
TROUBLE SYMPTOMS . . . . . . . . . . . . . . . 14-6
ON-VEHICLE SERVICE . . . . . . . . . . .14-22
ENGINE COOLANT LEAK CHECK . . . . . . 14-22
RADIATOR CAP VALVE OPENING
PRESSURE CHECK . . . . . . . . . . . . . . . . . . 14-22
ENGINE COOLANT REPLACEMENT . . . . 14-22
CONCENTRATION MEASUREMENT . . . . 14-23COOLING FAN MOTOR DRIVE CONTROL
UNIT CHECK . . . . . . . . . . . . . . . . . . . . . . . . 14-23
FAN CONTROL RELAY CONTINUITY
CHECK . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-24
COOLING FAN MOTOR CHECK . . . . . . . . 14-25
THERMOSTAT . . . . . . . . . . . . . . . . . .14-26
REMOVAL AND INSTALLATION . . . . . . . . 14-26
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . 14-27
WATER PUMP . . . . . . . . . . . . . . . . . .14-29
REMOVAL AND INSTALLATION <4G1> . . 14-29
REMOVAL AND INSTALLATION <4G6> . . 14-30
WATER HOSE AND WATER PIPE . .14-31
REMOVAL AND INSTALLATION <4G1> . . 14-31
REMOVAL AND INSTALLATION <4G6> . . 14-33
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . 14-34
RADIATOR . . . . . . . . . . . . . . . . . . . . .14-35
REMOVAL AND INSTALLATION . . . . . . . . 14-35
GENERAL INFORMATION
ENGINE COOLING14-2
GENERAL INFORMATION
M1141000100371The 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, pressure 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 thermostat 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 alternator drive belt from the
crankshaft. The radiator is the corrugated fin, down
flow type.
SERVICE SPECIFICATIONS
M1141000300416
LUBRICANT
M1141000400338
ItemSpecification
Radiator Performance kJ/h 4G13 Standard vehicles 137,720
Vehicles with capacity up radiator
(option)161,288
4G18 Standard vehicles 161,288
Vehicles with capacity up radiator
(option)181,800
4G63 181,800
A/T oil cooler Performance kJ/h 5,651
Item Standard value Limit
High-pressure valve opening pressure of radiator cap kPa 93 − 123 Minimum 83
Range of coolant antifreeze concentration of radiator % 30 − 60 -
Thermostat Valve opening temperature of
thermostat °C4G1 88 ± 1.5 -
4G6 82 ± 1.5 -
Full-opening temperature of
thermostat °C4G1 100 -
4G6 95 -
Valve lift mm 8.5 or more -
Item Specified coolant Quantity L
Engine coolant (including
condense tank)DIAQUEEN SUPER LONG LIFE COOLANT
or an equivalent4G1 5.0
4G6 7.0
SEALANTS
ENGINE COOLING14-3
SEALANTS
M1141000500324
SPECIAL TOOLS
M1141000600246
Item Specified sealant
Cylinder block drain plug 3M Nut Locking Part No.4171 or equivalent
Water pump <4G1>, Thermostat case
<4G6>, Cooling water outlet hose fitting
<4G6>MITSUBISHI GENUINE Part No.MD970389 or equivalent
Tool Number Name Use
MB991502 MUT-II sub assembly Reading diagnosis code
B991502
SPECIAL TOOLS
ENGINE COOLING14-4
MB991955
A: MB991824
B: MB991827
C: MB991910
D: MB991911
E: MB991825
F: MB991826MUT-III sub assembly
A: Vehicle
communication
interface (V.C.I.)
B: MUT-III USB cable
C: MUT-III main
harness A (Vehicles
with CAN
communication
system)
D: MUT-III main
harness B (Vehicles
without CAN
communication
system)
E: MUT-III
measurement
adapter
F: MUT-III trigger
harnessChecking the A/T
(Diagnosis display using the
MUT-III) Tool Number Name Use
MB991910
MB991826
MB991955
MB991911
MB991824
MB991827
MB991825
A
B
C
D
E
F
DO NOT USE
TROUBLESHOOTING
ENGINE COOLING14-5
TROUBLESHOOTING
INSPECTION CHART FOR TROUBLE
SYMPTOMS
M1141005600360
MB991223
A: MB991219
B: MB991220
C: MB991221
D: MB991222 Harness set
A: Test harness
B: LED harness
C: LED harness
adapter
D: ProbeMaking voltage and
resistance measurement
during troubleshooting
A: Connector pin contact
pressure inspection
B: Power circuit inspection
C: Power circuit inspection
D: Commercial tester
connection
MB991871 LLC changer Coolant refilling Tool Number Name Use
MB991223
A
B
C
D
AC
MB991871
Trouble symptom Inspection
procedure No.Reference page
Cooling fan (L.H.) and Cooling fan (R.H.) <4G1 (Vehicles with
A/C)> or A/C condenser fan <4G6> do not operate 1
P.14-6
Cooling fan (L.H.) and Cooling fan (R.H.) <4G1 (Vehicles with
A/C)> or A/C condenser fan <4G6> do not change speed or stop2
P.14-16
Cooling fan (L.H.) does not operate {When cooling fan (R.H.)
<4G1> or A/C condenser fan <4G6> operate} 3
P.14-20
Cooling fan (R.H.) <4G1> or A/C condenser fan <4G6> does not
operate {When cooling fan (L.H.) operate} 4
P.14-21
TROUBLESHOOTING
ENGINE COOLING14-8
STEP 3. Check the cooling fan motor drive
control unit connector A-18.
Q: Is the connector in good condition?
YES : .
Go to Step 4 .
NO : . Repair or replace the connector. Then go to
Step 24 .
STEP 4. Check the fusible link No.2.
Q: Is the fusible link No.2 in good condition?
YES : .
Go to Step 5 .
NO : . Replace the fusible link No.2. Then go to
Step 24 .
STEP 5. Measure the power supply voltage at fan
control relay connector A-09X.(1) Disconnect fan control relay connector A-09X
(remove the fan control relay) and measure relay
box side connector.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between fan control relay
connector A-09X terminal 4 and body earth.
•The voltage should measure system voltage.
(4) Turn the ignition switch to the "LOCK" (OFF)
position.
(5) Connect fan control relay connector A-09X
(install the fan control relay).
Q: Is the measured voltage system voltage?
YES :
Go to Step 8 .
NO : Go to Step 6 .
STEP 6. Check the fan control relay connector
A-09X.
Q: Is the connector in good condition?
YES :
Go to Step 7 .
NO : Repair the connector or replace the relay
box. Then go to Step 24 .
AC100293
A-18
321
Connector: A-18
AD
AC303509AB
Fusible link
No.2
Relay box
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X
AC303511AB
A-09X Connector
(Relay box side)
AC303510AB
Fan control relay
Relay boxConnector: A-09X
A-09X