COOLING

General Description
COOLING

1. General Description
A: SPECIFICATION
Cooling system Electric fan + Forced engine coolant circulation system
AT model:
Approx. 6.9 (7.3, 6.1)
Total engine coolant capacity 2 (US qt, Imp qt)
MT model:
Approx. 7.0 (7.4, 6.2)
Type Centrifugal impeller type
Discharge 20 2 (5.3 US gal, 4.4 Imp gal)/min.
Discharge perfor- Pump speed — Discharge
760 rpm — 2.9 kPa (0.3 mAq)
mance I pressure
Engine coolant temperature 80°C (176°F)
Discharge 100 2 (26.4 US gal, 22.0 Imp gal)/min.
Discharge perfor- Pump speed — Discharge
3,000 rpm — 49.0 kPa (5.0 mAq)
mance II pressure
Engine coolant temperature 80°C (176°F)
Water pump
Discharge 200 2 (52.8 US gal, 44.0 Imp gal)/min.
Discharge perfor- Pump speed — Discharge
6,000 rpm — 225.4 kPa (23.0 mAq)
mance III pressure
Engine coolant temperature 80°C (176°F)
Impeller diameter 76 mm (2.99 in)
Number of impeller vanes 8
Pump pulley diameter 60 mm (2.36 in)
Clearance between
Standard 0.5 — 1.5 mm (0.020 — 0.060 in)
impeller and case
Type Wax pellet type
Starts to open 80 — 84°C (176 — 183°F)
Thermostat Fully opened 95°C (203°F)
Valve lift 9.0 mm (0.354 in) or more
Valve bore 35 mm (1.38 in)
Main fan 120 W
Motor
Sub fan 120 W
Radiator fan
320 mm (12.60 in) × 5 (main fan)
Fan diameter × Blade
320 mm (12.60 in) × 7 (sub fan)
Type Down flow
691.5 × 340 × 16 mm
Core dimensions Width × Height × Thickness
(27.22 × 13.39 × 0.63 in)
Above: 108±15 kPa
Radiator
(1.1±0.15 kgf/cm2, 16±2 psi)
Pressure range in which cap valve is open
Below: −1.0 to −4.9 kPa
(−0.01 to −0.05 kgf/cm2, −0.1 to −0.7 psi)
Fins Corrugated fin type
Reservoir
Capacity 0.5 2 (0.5 US qt, 0.4 Imp qt)
tank

CO(H4SO)-2
 General Description
COOLING

B: COMPONENT
1. WATER PUMP

(2)

(1)

T1

(3)

T1

(4)

T2 (5)

(6)

CO-00265

(1) Water pump ASSY (5) Gasket Tightening torque: N⋅m (kgf-m, ft-lb)
(2) Gasket (6) Thermostat cover T1: First 12 (1.2, 8.7)
(3) Heater by-pass hose Second 12 (1.2, 8.7)
(4) Thermostat T2: 12 (1.2, 8.7)

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 General Description
COOLING

2. RADIATOR AND RADIATOR FAN

(8)
(6) (5)
T5
(10) (12)
(7)

T3 (5)
T5
(15)

(4)
T1
(3) T4

(9)

(11) (13)
(24) (25)

T1 (16)
(17) T2
(2)
T4 (16)
(14)

(18)
(21) (16)
T2
(16)

(1)
(16)
(23) (19)
(20)
(16)
(5)

(22)

CO-02248

(1) Radiator lower cushion (12) Radiator sub fan motor (23) Radiator lower bracket
(2) Radiator (13) Radiator main fan shroud (24) Radiator drain plug
(3) Radiator upper cushion (14) Radiator main fan (25) Radiator cap
(4) Radiator upper bracket (15) Radiator main fan motor
(5) Clamp (16) ATF hose clamp (AT model) Tightening torque: N⋅m (kgf-m, ft-lb)
(6) Radiator inlet hose (17) ATF inlet hose A (AT model) T1: 4.4 (0.45, 3.3)
(7) Engine coolant reservoir tank cap (18) ATF outlet hose A (AT model) T2: 12 (1.2, 8.7)
(8) Overflow hose (19) ATF pipe (AT model) T3: 18 (1.8, 13.0)
(9) Engine coolant reservoir tank (20) ATF inlet hose B (AT model) T4: 3.4 (0.35, 2.5)
(10) Radiator sub fan shroud (21) ATF outlet hose B (AT model) T5: 4.9 (0.50, 3.6)
(11) Radiator sub fan (22) Radiator outlet hose

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 General Description
COOLING

C: CAUTION
• Wear work clothing, including a cap, protective goggles, and protective shoes during operation.
• Remove contamination including dirt and corrosion before removal, installation or disassembly.
• Keep the disassembled parts in order and protect them from dust and dirt.
• Before removal, installation or disassembly, be sure to clarify the failure. Avoid unnecessary removal, in-
stallation, disassembly and replacement.
• Be careful not to burn your hands, because each part in the vehicle is hot after running.
• Be sure to tighten fasteners including bolts and nuts to the specified torque.
• Place shop jacks or rigid racks at the specified points.
• Before disconnecting electrical connectors of sensors or units, be sure to disconnect the ground cable from
battery.
D: PREPARATION TOOL
1. SPECIAL TOOL
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
499977100 CRANK PULLEY Used for stopping rotation of crank pulley when
WRENCH loosening and tightening crankshaft pulley bolt.

ST-499977100
18231AA010 CAM SPROCKET • Used for removing and installing cam
WRENCH sprocket.
• Also the CAM SPROCKET WRENCH
(499207100) can be used.

ST18231AA010

CO(H4SO)-5
 Radiator Main Fan System
COOLING

2. Radiator Main Fan System

A: WIRING DIAGRAM

IGNITION
SWITCH
SBF-1 SBF-4

No.17
No.18
A/C RELAY HOLDER A/C RELAY HOLDER
1 3
20A
20A
2 4

MAIN 31 8
SUB
FAN 34 5 FAN
RELAY 1 32 7 RELAY 1
30 9

MAIN 28 21
SUB
FAN 25 24 FAN
RELAY 2 27 22 RELAY 2
29 20

F27
F27

MAIN FAN MOTOR SUB FAN MOTOR

2 2

1 1
F45
3
12

3
2

4 B62
4

F17 F16

E E
E

18
B136 ECM
29

F45
F16 F27
1 2 3 4 5 6 7 8 9 10 11
F17 12 13 14 15 16 17 18 19 20 21 22 23 24
1 2 5 6 7 10 15 16 17 20 25 26 27 30 35
8 11 18 21 28 31
1 2 3 4 9 12 13 14 19 22 23 24 29 32 33 34 36
3 4 B136
RELAY HOLDER (BLACK)
1 2 3 4 5 6
7 8 9 10 11 12 13 14 15 16
17 18 19 20 21 22 23 24 25 26 27
28 29 30 31 32 33 34 35
CO-02237

CO(H4SO)-6
 Radiator Main Fan System
COOLING

B: INSPECTION
DETECTING CONDITION:
• Engine coolant temperature is above 96°C (205°F).
• A/C compressor is rotated.
• Vehicle speed is below 19 km/h (12 MPH).
TROUBLE SYMPTOM:
• Radiator main fan does not rotate under the above conditions.
• Radiator main fan does not rotate at high speed when the following conditions are both met:
(1) Engine coolant temperature is above 90°C (194°F).
(2) A/C is ON.

Step Check Yes No

1 CHECK OPERATION OF RADIATOR. Does the main radiator fan Go to step 2. Go to step 3.
1) Run the engine at idle. (Vehicle stationary) rotate?
2) Turn the A/C switch to OFF.
3) Warm the engine coolant temperature over
96°C (205°F).
2 CHECK OPERATION OF RADIATOR. Does the main radiator fan Radiator main fan Go to step 17.
Turn the A/C switch to ON at condition of step rotate faster when A/C com- system is okay.
1. pressor is operated?
3 CHECK POWER SUPPLY TO MAIN FAN MO- Is the voltage more than 10 V? Go to step 4. Go to step 7.
TOR.
CAUTION:
Be careful not to overheat the engine during
repair.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from main fan
motor.
3) Start the engine, and warm it up until
engine coolant temperature increases over
96°C (205°F).
4) Stop the engine and turn ignition switch to
ON.
5) Measure the voltage between main fan
motor connector and chassis ground.
Connector & terminal
(F17) No. 1 (+) — Chassis ground (−):
4 CHECK GROUND CIRCUIT OF MAIN FAN Is the resistance less than 5 Go to step 5. Repair the open
MOTOR. Ω? circuit in harness
1) Turn the ignition switch to OFF. between main fan
2) Measure the resistance between main fan motor connector
motor connector and chassis ground. and chassis
Connector & terminal ground.
(F17) No. 3 — Chassis ground:
(F17) No. 4 — Chassis ground:
5 CHECK POOR CONTACT. Is there poor contact in main Repair the poor Go to step 6.
Check poor contact in main fan motor connec- fan motor connector? contact in main fan
tor. motor connector.
6 CHECK MAIN FAN MOTOR. Does the main fan rotate? Repair the poor Replace the main
Connect the battery positive (+) terminal to ter- contact in main fan fan motor with a
minal No. 1, and ground (−) terminal to termi- motor connector. new one.
nal No. 3 or No. 4 of main fan motor connector.

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 Radiator Main Fan System
COOLING

Step Check Yes No

7 CHECK POWER SUPPLY TO MAIN FAN Is the voltage more than 10 V? Go to step 8. Go to step 9.
RELAY1.
1) Turn the ignition switch to OFF.
2) Remove the main fan relay1 from A/C relay
holder.
3) Measure the voltage between main fan
relay1 terminal and chassis ground.
Connector & terminal
(F27) No. 31 (+) — Chassis ground (−):
8 CHECK POWER SUPPLY TO MAIN FAN Is the voltage more than 10 V? Go to step 12. Go to step 11.
RELAY1.
1) Turn the ignition switch to ON.
2) Measure the voltage between main fan
relay1 terminal and chassis ground.
Connector & terminal
(F27) No. 34 (+) — Chassis ground (−):
9 CHECK 20 A FUSE. Is the fuse blown out? Replace the fuse. Go to step 10.
1) Remove the 20 A fuse from A/C relay
holder.
2) Check the condition of fuse.
10 CHECK POWER SUPPLY TO A/C RELAY Is the voltage more than 10 V? Repair the open Repair the open
HOLDER 20 A FUSE TERMINAL. circuit in harness circuit in harness
Measure the voltage of harness between A/C between 20 A fuse between main fuse
relay holder 20 A fuse terminal and chassis and main fan relay box connector and
ground. terminal. 20 A fuse terminal.
Connector & terminal
(F27) No. 1 (+) — Chassis ground (−):
11 CHECK FUSE. Is the fuse blown out? Replace the fuse. Repair the open
1) Turn the ignition switch to OFF. circuit in harness
2) Remove the fuse No. 18 from joint box. between main fan
3) Check the condition of fuse. relay and ignition
switch.
12 CHECK MAIN FAN RELAY. Is the resistance more than 1 Go to step 13. Replace the main
1) Turn the ignition switch to OFF. MΩ? fan relay.
2) Remove the main fan relay1.
3) Measure the resistance of main fan relay1.
Terminals
No. 30 — No. 31:
13 CHECK MAIN FAN RELAY. Is the resistance less than 1 Go to step 14. Replace the main
1) Connect the battery to terminals No. 34 and Ω? fan relay.
No. 32 of main fan relay1.
2) Measure the resistance of main fan relay1.
Terminals
No. 30 — No. 31:
14 CHECK HARNESS BETWEEN MAIN FAN Is the resistance less than 1 Go to step 15. Repair the open
RELAY TERMINAL AND MAIN FAN MOTOR Ω? circuit in harness
CONNECTOR. between main fan
Measure the resistance of harness between motor connector
main fan motor connector and main fan relay and main fan relay
terminal. terminal.
Connector & terminal
(F17) No. 1 — (F27) No. 30:

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 Radiator Main Fan System
COOLING

Step Check Yes No

15 CHECK HARNESS BETWEEN MAIN FAN Is the resistance less than 1 Go to step 16. Repair the open
RELAY AND ECM. Ω? circuit in harness
1) Turn the ignition switch to OFF. between main fan
2) Disconnect the connector from ECM. relay and ECM.
3) Measure the resistance of harness
between main fan relay connector and ECM
connector.
Connector & terminal
(F27) No. 32 — (B136) No. 18:
16 CHECK POOR CONTACT. Is there poor contact in con- Repair the poor Record the DTC.
nector between main fan motor contact connector. Repair the trouble
Check poor contact in connector between main
fan and ECM. and ECM? cause. <Ref. to
EN(H4SO)(diag)-
35, Read Diagnos-
tic Trouble Code
(DTC).>
17 CHECK POWER SUPPLY TO MAIN FAN MO- Is the voltage more than 10 V? Go to step 18. Go to step 20.
TOR.
CAUTION:
Be careful not to overheat the engine during
repair.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from main fan
motor.
3) Start the engine, and warm it up until
engine coolant temperature increases over
96°C (205°F).
4) Turn the A/C switch ON.
5) Measure the voltage while A/C compressor
is rotating.
6) Measure the voltage between main fan
motor connector and chassis ground.
Connector & terminal
(F17) No. 2 (+) — Chassis ground (−):
18 CHECK POOR CONTACT. Is there poor contact in main Repair the poor Go to step 19.
Check poor contact in main fan motor connec- fan motor connector? contact in main fan
tor. motor connector.
19 CHECK MAIN FAN MOTOR. Does the main fan rotate? Repair the poor Replace the main
Connect the battery positive (+) terminal to ter- contact in main fan fan motor with a
minal No. 2, and ground (−) terminal to termi- motor connector. new one.
nal No. 3 or No. 4 of main fan motor connector.
20 CHECK POWER SUPPLY TO MAIN FAN Is the voltage more than 10 V? Go to step 21. Go to step 22.
RELAY2.
1) Turn the ignition switch to OFF.
2) Remove the main fan relay2 from A/C relay
holder.
3) Measure the voltage between main fan
relay2 terminal and chassis ground.
Connector & terminal
(F27) No. 28 (+) — Chassis ground (−):
21 CHECK POWER SUPPLY TO MAIN FAN Is the voltage more than 10 V? Go to step 25. Go to step 24.
RELAY2.
1) Turn the ignition switch to ON.
2) Measure the voltage between main fan
relay2 terminal and chassis ground.
Connector & terminal
(F27) No. 25 (+) — Chassis ground (−):

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 Radiator Main Fan System
COOLING

Step Check Yes No

22 CHECK 20 A FUSE. Is the fuse blown out? Replace the fuse. Go to step 23.
1) Remove the 20 A fuse from A/C relay
holder.
2) Check the condition of fuse.
23 CHECK POWER SUPPLY TO A/C RELAY Is the voltage more than 10 V? Repair the open Repair the open
HOLDER 20 A FUSE TERMINAL. circuit in harness circuit in harness
Measure the voltage of harness between A/C between 20 A fuse between main fuse
relay holder 20 A fuse terminal and chassis and main fan relay box connector and
ground. terminal. 20 A fuse terminal.
Connector & terminal
(F27) No. 1 (+) — Chassis ground (−):
24 CHECK FUSE. Is the fuse blown out? Replace the fuse. Repair the open
1) Turn the ignition switch to OFF. circuit in harness
2) Remove the fuse No. 18 from joint box. between main fan
3) Check the condition of fuse. relay and ignition
switch.
25 CHECK MAIN FAN RELAY. Is the resistance more than 1 Go to step 26. Replace the main
1) Turn the ignition switch to OFF. MΩ? fan relay.
2) Remove the main fan relay2.
3) Measure the resistance of main fan relay2.
Terminals
No. 28 — No. 29:
26 CHECK MAIN FAN RELAY. Is the resistance less than 1 Go to step 27. Replace the main
1) Connect the battery to terminals No. 25 and Ω? fan relay.
No. 27 of main fan relay2.
2) Measure the resistance of main fan relay2.
Terminals
No. 28 — No. 29:
27 CHECK HARNESS BETWEEN MAIN FAN Is the resistance less than 1 Go to step 28. Repair the open
RELAY TERMINAL AND MAIN FAN MOTOR Ω? circuit in harness
CONNECTOR. between main fan
Measure the resistance of harness between motor connector
main fan motor connector and main fan relay and main fan relay
terminal. terminal.
Connector & terminal
(F17) No. 2 — (F27) No. 29:
28 CHECK HARNESS BETWEEN MAIN FAN Is the resistance less than 1 Go to step 29. Repair the open
RELAY AND ECM. Ω? circuit in harness
1) Turn the ignition switch to OFF. between main fan
2) Disconnect the connector from ECM. relay and ECM.
3) Measure the resistance of harness
between main fan relay connector and ECM
connector.
Connector & terminal
(F27) No. 27 — (B136) No. 29:
29 CHECK POOR CONTACT. Is there poor contact in con- Repair the poor Record the DTC.
Check poor contact in connector between main nector between main fan motor contact connector. Repair the trouble
fan and ECM. and ECM? cause. <Ref. to
EN(H4SO)(diag)-
35, Read Diagnos-
tic Trouble Code
(DTC).>

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 Radiator Sub Fan System
COOLING

3. Radiator Sub Fan System

A: WIRING DIAGRAM

IGNITION
SWITCH
SBF-1 SBF-4

No.17
No.18
A/C RELAY HOLDER A/C RELAY HOLDER
1 3
20A
20A
2 4

MAIN 31 8
SUB
FAN 34 5 FAN
RELAY 1 32 7 RELAY 1
30 9

MAIN 28 21
SUB
FAN 25 24 FAN
RELAY 2 27 22 RELAY 2
29 20

F27
F27

MAIN FAN MOTOR SUB FAN MOTOR

2 2

1 1
F45
3
12

3
2

4 B62
4

F17 F16

E E
E

18
B136 ECM
29

F45
F16 F27
1 2 3 4 5 6 7 8 9 10 11
F17 12 13 14 15 16 17 18 19 20 21 22 23 24
1 2 5 6 7 10 15 16 17 20 25 26 27 30 35
8 11 18 21 28 31
1 2 3 4 9 12 13 14 19 22 23 24 29 32 33 34 36
3 4 B136
RELAY HOLDER (BLACK)
1 2 3 4 5 6
7 8 9 10 11 12 13 14 15 16
17 18 19 20 21 22 23 24 25 26 27
28 29 30 31 32 33 34 35
CO-02237

CO(H4SO)-11
 Radiator Sub Fan System
COOLING

B: INSPECTION
DETECTING CONDITION:
• Engine coolant temperature is above 96°C (205°F).
• A/C compressor is rotated.
• Vehicle speed is below 19 km/h (12 MPH).
TROUBLE SYMPTOM:
• Radiator sub fan does not rotate under the above conditions.
• Radiator sub fan does not rotate at high speed when the following conditions are both met:
(1) Engine coolant temperature is above 90°C (194°F).
(2) A/C is ON.

Step Check Yes No

1 CHECK OPERATION OF RADIATOR. Does the radiator sub fan Go to step 2. Go to step 3.
1) Run the engine at idle. (Vehicle stationary) rotate?
2) Turn the A/C switch to OFF.
3) Warm the engine coolant temperature over
96°C (205°F).
2 CHECK OPERATION OF RADIATOR. Does the radiator sub fan Radiator sub fan Go to step 17.
Turn the A/C switch to ON at condition of step rotate faster when A/C com- system is okay.
1. pressor is operated?
3 CHECK POWER SUPPLY TO SUB FAN MO- Is the voltage more than 10 V? Go to step 4. Go to step 7.
TOR.
CAUTION:
Be careful not to overheat the engine during
repair.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from sub fan
motor.
3) Start the engine, and warm it up until
engine coolant temperature increases over
96°C (205°F).
4) Stop the engine and turn ignition switch to
ON.
5) Measure the voltage between sub fan
motor connector and chassis ground.
Connector & terminal
(F16) No. 1 (+) — Chassis ground (−):
4 CHECK GROUND CIRCUIT OF SUB FAN Is the resistance less than 5 Go to step 5. Repair the open
MOTOR. Ω? circuit in harness
1) Turn the ignition switch to OFF. between sub fan
2) Measure the resistance between sub fan motor connector
motor connector and chassis ground. and chassis
Connector & terminal ground.
(F16) No. 3 — Chassis ground:
(F16) No. 4 — Chassis ground:
5 CHECK POOR CONTACT. Is there poor contact in sub fan Repair the poor Go to step 6.
Check poor contact in sub fan motor connec- motor connector? contact in sub fan
tor. motor connector.
6 CHECK SUB FAN MOTOR. Does the sub fan rotate? Repair the poor Replace the sub
Connect the battery positive (+) terminal to ter- contact in sub fan fan motor with a
minal No. 1, and ground (−) terminal to termi- motor connector. new one.
nal No. 3 or No. 4 of sub fan motor connector.

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 Radiator Sub Fan System
COOLING

Step Check Yes No

7 CHECK POWER SUPPLY TO SUB FAN Is the voltage more than 10 V? Go to step 8. Go to step 9.
RELAY1.
1) Turn the ignition switch to OFF.
2) Remove the sub fan relay1 from A/C relay
holder.
3) Measure the voltage between sub fan
relay1 terminal and chassis ground.
Connector & terminal
(F27) No. 8 (+) — Chassis ground (−):
8 CHECK POWER SUPPLY TO SUB FAN Is the voltage more than 10 V? Go to step 12. Go to step 11.
RELAY1.
1) Turn the ignition switch to ON.
2) Measure the voltage between sub fan
relay1 terminal and chassis ground.
Connector & terminal
(F27) No. 5 (+) — Chassis ground (−):
9 CHECK 20 A FUSE. Is the fuse blown out? Replace the fuse. Go to step 10.
1) Remove the 20 A fuse from A/C relay
holder.
2) Check the condition of fuse.
10 CHECK POWER SUPPLY TO A/C RELAY Is the voltage more than 10 V? Repair the open Repair the open
HOLDER 20 A FUSE TERMINAL. circuit in harness circuit in harness
Measure the voltage of harness between A/C between 20 A fuse between sub fuse
relay holder 20 A fuse terminal and chassis and sub fan relay box connector and
ground. terminal. 20 A fuse terminal.
Connector & terminal
(F27) No. 3 (+) — Chassis ground (−):
11 CHECK FUSE. Is the fuse blown out? Replace the fuse. Repair the open
1) Turn the ignition switch to OFF. circuit in harness
2) Remove the fuse No. 17 from joint box. between sub fan
3) Check the condition of fuse. relay and ignition
switch.
12 CHECK SUB FAN RELAY. Is the resistance more than 1 Go to step 13. Replace the sub
1) Turn the ignition switch to OFF. MΩ? fan relay.
2) Remove the sub fan relay1.
3) Measure the resistance of sub fan relay1.
Terminals
No. 8 — No. 9:
13 CHECK SUB FAN RELAY. Is the resistance less than 1 Go to step 14. Replace the sub
1) Connect the battery to terminals No. 5 and Ω? fan relay.
No. 7 of sub fan relay1.
2) Measure the resistance of sub fan relay.
Terminals
No. 8 — No. 9:
14 CHECK HARNESS BETWEEN SUB FAN RE- Is the resistance less than 1 Go to step 15. Repair the open
LAY TERMINAL AND SUB FAN MOTOR Ω? circuit in harness
CONNECTOR. between sub fan
Measure the resistance of harness between motor connector
sub fan motor connector and sub fan relay ter- and sub fan relay
minal. terminal.
Connector & terminal
(F16) No. 1 — (F27) No. 9:

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 Radiator Sub Fan System
COOLING

Step Check Yes No

15 CHECK HARNESS BETWEEN SUB FAN RE- Is the resistance less than 1 Go to step 16. Repair the open
LAY AND ECM. Ω? circuit in harness
1) Turn the ignition switch to OFF. between sub fan
2) Disconnect the connector from ECM. relay and ECM.
3) Measure the resistance of harness
between sub fan relay connector and ECM
connector.
Connector & terminal
(F27) No. 7 — (B136) No. 18:
16 CHECK POOR CONTACT. Is there poor contact in con-
Repair the poor Record the DTC.
Check poor contact in connector between sub nector between sub fan motor
contact connector. Repair the trouble
fan and ECM. and ECM? cause. <Ref. to
EN(H4SO)(diag)-
35, Read Diagnos-
tic Trouble Code
(DTC).>
17 CHECK POWER SUPPLY TO SUB FAN MO- Is the voltage more than 10 V? Go to step 18. Go to step 20.
TOR.
CAUTION:
Be careful not to overheat the engine during
repair.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from sub fan
motor.
3) Start the engine, and warm it up until
engine coolant temperature increases over
96°C (205°F).
4) Turn the A/C switch ON.
5) Measure the voltage while A/C compressor
is rotating.
6) Measure the voltage between sub fan
motor connector and chassis ground.
Connector & terminal
(F16) No. 2 (+) — Chassis ground (−):
18 CHECK POOR CONTACT. Is there poor contact in sub fan Repair the poor Go to step 19.
Check poor contact in sub fan motor connec- motor connector? contact in sub fan
tor. motor connector.
19 CHECK SUB FAN MOTOR. Does the sub fan rotate? Repair the poor Replace the sub
Connect the battery positive (+) terminal to ter- contact in sub fan fan motor with a
minal No. 2, and ground (−) terminal to termi- motor connector. new one.
nal No. 3 or No. 4 of sub fan motor connector.
20 CHECK POWER SUPPLY TO SUB FAN Is the voltage more than 10 V? Go to step 21. Go to step 22.
RELAY2.
1) Turn the ignition switch to OFF.
2) Remove the sub fan relay2 from A/C relay
holder.
3) Measure the voltage between sub fan
relay2 terminal and chassis ground.
Connector & terminal
(F27) No. 21 (+) — Chassis ground (−):
21 CHECK POWER SUPPLY TO SUB FAN Is the voltage more than 10 V? Go to step 25. Go to step 24.
RELAY2.
1) Turn the ignition switch to ON.
2) Measure the voltage between sub fan
relay2 terminal and chassis ground.
Connector & terminal
(F27) No. 24 (+) — Chassis ground (−):

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 Radiator Sub Fan System
COOLING

Step Check Yes No

22 CHECK 20 A FUSE. Is the fuse blown out? Replace the fuse. Go to step 23.
1) Remove the 20 A fuse from A/C relay
holder.
2) Check the condition of fuse.
23 CHECK POWER SUPPLY TO A/C RELAY Is the voltage more than 10 V? Repair the open Repair the open
HOLDER 20 A FUSE TERMINAL. circuit in harness circuit in harness
Measure the voltage of harness between A/C between 20 A fuse between sub fuse
relay holder 20 A fuse terminal and chassis and sub fan relay box connector and
ground. terminal. 20 A fuse terminal.
Connector & terminal
(F27) No. 3 (+) — Chassis ground (−):
24 CHECK FUSE. Is the fuse blown out? Replace the fuse. Repair the open
1) Turn the ignition switch to OFF. circuit in harness
2) Remove the fuse No. 17 from joint box. between sub fan
3) Check the condition of fuse. relay and ignition
switch.
25 CHECK SUB FAN RELAY. Is the resistance more than 1 Go to step 26. Replace the sub
1) Turn the ignition switch to OFF. MΩ? fan relay.
2) Remove the sub fan relay2.
3) Measure the resistance of sub fan relay2.
Terminals
No. 20 — No. 21:
26 CHECK SUB FAN RELAY. Is the resistance less than 1 Go to step 27. Replace the sub
1) Connect the battery to terminals No. 22 and Ω? fan relay.
No. 24 of sub fan relay2.
2) Measure the resistance of sub fan relay2.
Terminals
No. 20 — No. 21:
27 CHECK HARNESS BETWEEN SUB FAN RE- Is the resistance less than 1 Go to step 28. Repair the open
LAY TERMINAL AND SUB FAN MOTOR Ω? circuit in harness
CONNECTOR. between sub fan
Measure the resistance of harness between motor connector
sub fan motor connector and sub fan relay2 and sub fan relay
terminal. terminal.
Connector & terminal
(F16) No. 2 — (F27) No. 20:
28 CHECK HARNESS BETWEEN SUB FAN RE- Is the resistance less than 1 Go to step 29. Repair the open
LAY AND ECM. Ω? circuit in harness
1) Turn the ignition switch to OFF. between sub fan
2) Disconnect the connector from ECM. relay and ECM.
3) Measure the resistance of harness
between sub fan relay connector and ECM
connector.
Connector & terminal
(F27) No. 22 — (B136) No. 29:
29 CHECK POOR CONTACT. Is there poor contact in con- Repair the poor Record the DTC.
Check poor contact in connector between sub nector between sub fan motor contact connector. Repair the trouble
fan and ECM. and ECM? cause. <Ref. to
EN(H4SO)(diag)-
35, Read Diagnos-
tic Trouble Code
(DTC).>

CO(H4SO)-15
 Engine Coolant
COOLING

4. Engine Coolant 3) Fill engine coolant into the reservoir tank up to

“FULL” level.
A: REPLACEMENT
1. DRAINING OF ENGINE COOLANT
1) Lift-up the vehicle.
2) Remove the under cover.
3) Remove the drain plug to drain engine coolant FULL
into container.
FULL

LOW
LOW
NOTE:
• Remove the radiator cap so that engine coolant
will drain faster. CO-00010
• If engine coolant adheres to the exhaust pipe,
wipe it off completely. 4) Close the radiator cap and start the engine.
Race 5 to 6 times at less than 3,000 rpm, then stop
the engine. (Complete this operation within 40 sec-
onds.)
5) Wait for one minute after the engine stops, open
the radiator cap. If the engine coolant level drops,
add engine coolant into radiator up to the filler neck
position.
6) Perform the procedures 4) and 5) again.
7) Attach the radiator cap and reservoir tank cap
properly.
CO-00009 8) Start the engine and operate the heater at max-
imum hot position and the blower speed setting to
4) Install the drain plug. “LO”.
2. FILLING OF ENGINE COOLANT 9) Run the engine at 2,000 rpm or less until radiator
fan starts and stops.
1) Pour cooling system conditioner through the fill-
er neck. NOTE:
• Be careful with the engine coolant temperature
Cooling system protective agent: gauge to prevent overheating.
COOLING SYSTEM CONDITIONER (Part No. • If the radiator hose becomes to harden by the
SOA635071) pressure of engine coolant, air bleeding operation
2) Fill engine coolant into the radiator up to filler seems to be almost completed.
neck position. 10) Stop the engine and wait until engine coolant
Coolant capacity (fill up to “FULL” level): temperature lowers to 30°C (86°F).
AT model: 11) Open the radiator cap. If the engine coolant lev-
Approx. 6.9 2 (7.3 US qt, 6.1 Imp qt) el drops, add engine coolant into radiator up to the
MT model: filler neck position and reservoir tank to “FULL” lev-
Approx. 7.0 2 (7.4 US qt, 6.2 Imp qt) el.
12) Attach the radiator cap and reservoir tank cap
NOTE: properly.
The SUBARU Genuine Coolant containing anti- 13) Operate the heater at maximum hot position
freeze and anti-rust agents is especially made for and the blower speed setting to “LO” and start the
SUBARU engine, which has an aluminum crank- engine. Race at less than 3,000 rpm. If the flowing
case. Always use SUBARU Genuine Coolant, sound is heard at this time, perform the procedures
since other coolant may cause corrosion. from 9) again.

CO(H4SO)-16
 Engine Coolant
COOLING

B: INSPECTION 2. PROCEDURE TO ADJUST THE CON-

CENTRATION OF THE COOLANT
1. RELATIONSHIP OF SUBARU COOLANT
CONCENTRATION AND FREEZING TEM- To adjust the concentration of the coolant accord-
PERATURE ing to temperature, find the proper fluid concentra-
tion in the above diagram and replace the
The concentration and safe operating temperature necessary amount of coolant with an undiluted so-
of the SUBARU coolant is shown in the diagram. lution of SUBARU genuine coolant (concentration
Measuring the temperature and specific gravity of 50%).
the coolant will provide this information. The amount of coolant that should be replaced can
[Example] be determined using the diagram.
If the coolant temperature is 25°C (77°F) and its [Example]
specific gravity is 1.054 and the concentration is Assume that the coolant concentration must be in-
35% (point A), the safe operating temperature is − creased from 25% to 40%. Find point A, where the
14°C (7°F) (point B), and the freezing temperature 25% line of coolant concentration intersects with
is −20°C (−4°F) (point C). the 40% curve of the necessary coolant concentra-
tion, and read the scale on the vertical axis of the
Specific gravity

Safe operating temperature graph at height A. The quantity of coolant to be

drained is 2.12 (2.2 US qt, 1.8 Imp qt). Drain 2.1 2
of coolant

Concentration
of coolant (2.2 US qt, 1.8 Imp qt) of coolant from the cooling
system and add 2.12 (2.2 US qt, 1.8 Imp qt) of the
1.100 undiluted solution of SUBARU coolant.
If a coolant concentration of 50% is needed, drain
1.090
60%
all the coolant and refill with the undiluted solution
1.080 only.
1.070 B 50%
C
Quantity of coolant to be
drained (US qt, Imp qt)

1.060
(1.054)
A 40%
1.050

1.040 30%
Freezing
1.030
temperature Necessary Concentration
20%
1.020 of coolant
(77 F)

10%
25 C

1.010
3
(3.2, 45%
1.000
-40 -30 -20 -10 0 10 20 30 40 2.6) A
(-40) (-22) (-4) (14) (32) (50) (68) (86) (104) 2 40%
Coolant temperature C ( F) 35%
CO-02172 (2.1,
1.8) 30%
1 25%
(1.1, 20%
0.9)
10% 15%
0
10 20 30 40 50
Concentration of coolant in
the vehicie cooling system %

Concentration of coolant in vehicie

and quantity to be drained
CO-00012

CO(H4SO)-17
 Water Pump
COOLING

5. Water Pump 8) Remove the belt cover No. 2 (LH).

A: REMOVAL
1) Remove the radiator. <Ref. to CO(H4SO)-23,
REMOVAL, Radiator.>
2) Remove the V-belts.
<Ref. to ME(H4SO)-40, REMOVAL, V-belt.>
3) Remove the crank pulley.
<Ref. to ME(H4SO)-42, REMOVAL, Crank Pul-
ley.>
4) Remove the timing belt.
CO-00019
<Ref. to ME(H4SO)-44, TIMING BELT, REMOV-
AL, Timing Belt.> 9) Remove the tensioner bracket.
5) Remove the automatic belt tension adjuster.

CO-00020
CO-00016
10) Disconnect the hose from water pump.
6) Remove the belt idler No. 2. 11) Remove the water pump.

CO-00017 CO-00021

7) Remove the cam sprocket (LH) by using ST. B: INSTALLATION

ST 18231AA010 CAM SPROCKET WRENCH 1) Install the water pump onto cylinder block (LH).
NOTE: NOTE:
Also the CAM SPROCKET WRENCH (499207100) • Replace the gasket with a new one.
can be used. • When installing the water pump, tighten the bolts
in two stages in alphabetical sequence as shown in
the figure.
ST

CO-00018

CO(H4SO)-18
 Water Pump
COOLING

Tightening torque: Tightening torque:

First: 78 N⋅m (8.0 kgf-m, 57.9 ft-lb)
12 N⋅m (1.2 kgf-m, 8.7 ft-lb)
Second:
12 N⋅m (1.2 kgf-m, 8.7 ft-lb) ST

(B)
(C)
(A)
(D)

(E) (F)
CO-00018

6) Install the belt idler No. 2.

ME-02463 Tightening torque:
39 N⋅m (4.0 kgf-m, 28.9 ft-lb)
2) Connect the hose to water pump.
3) Install the tensioner bracket.
Tightening torque:
24.5 N⋅m (2.5 kgf-m, 18.1 ft-lb)

CO-00017

7) Install the automatic belt tension adjuster whose

tension rod is held with pin. <Ref. to ME(H4SO)-45,
AUTOMATIC BELT TENSION ADJUSTER AS-
CO-00020 SEMBLY AND BELT IDLER, INSTALLATION,
4) Install the belt cover No. 2 (LH). Timing Belt.>
8) Install the timing belt. <Ref. to ME(H4SO)-46,
Tightening torque: TIMING BELT, INSTALLATION, Timing Belt.>
5 N⋅m (0.5 kgf-m, 3.6 ft-lb) 9) Install the crank pulley. <Ref. to ME(H4SO)-42,
INSTALLATION, Crank Pulley.>
10) Install the V-belts. <Ref. to ME(H4SO)-40, IN-
STALLATION, V-belt.>
11) Install the radiator. <Ref. to CO(H4SO)-24, IN-
STALLATION, Radiator.>
C: INSPECTION
1) Check the water pump bearing for smooth rota-
tion.
2) Check the water pump pulley for abnormalities.
CO-00019 3) Check the impeller for damage or abnormal de-
5) Install the cam sprockets (LH) by using ST. formation.
ST 18231AA010 CAM SPROCKET WRENCH 4) Check the clearance between impeller and
pump case.
NOTE:
Also the CAM SPROCKET WRENCH (499207100)
can be used.

CO(H4SO)-19
 Water Pump
COOLING

Clearance between impeller and pump case:

Standard
0.5 — 1.5 mm (0.020 — 0.060 in)

CO-00293

5) After water pump installation, check the pulley

shaft for engine coolant leaks. If leaks are noted,
replace the water pump assembly.

CO(H4SO)-20
 Thermostat
COOLING

6. Thermostat 6) Remove the thermostat cover, and then remove

the gasket and thermostat.
A: REMOVAL
1) Set the vehicle on a lift.
2) Lift-up the vehicle.
3) Remove the under cover.
4) Drain the engine coolant completely. <Ref. to
CO(H4SO)-16, DRAINING OF ENGINE COOL-
ANT, REPLACEMENT, Engine Coolant.>

(C)

CO-00009 (B)
5) Disconnect the radiator outlet hose from thermo-
stat cover. (A)

CO-00271

(A) Thermostat cover

(B) Gasket
(C) Thermostat

B: INSTALLATION
1) Install a gasket to thermostat, and install the
thermostat and gasket to water pump as a unit.
CO-00270 Then, install the thermostat cover.
NOTE:
• When reinstalling the thermostat, use a new gas-
ket.
• The thermostat must be installed with the jiggle
pin facing to the up side.

CO(H4SO)-21
 Thermostat
COOLING

Tightening torque: C: INSPECTION

12 N⋅m (1.2 kgf-m, 8.7 ft-lb) Replace the thermostat if the valve does not close
completely at an ambient temperature or if the fol-
lowing test shows unsatisfactory results.
• Inspection method
Immerse the thermostat and a thermometer in wa-
ter. Raise water temperature gradually, and mea-
sure the temperature and valve lift when the valve
begins to open and when the valve is fully opened.
During the test, agitate the water for even temper-
ature distribution. The measured value should
meet the specification.
NOTE:
(D)
• Leave the thermostat in the boiling water for
more than five minutes before measuring the valve
lift.
T • Hold the thermostat with a wire or the like to
(C) avoid contacting with container bottom.

(B)
Starting temperature to open:
80 — 84°C (176 — 183°F)
(A) Fully opens:
95°C (203°F)
CO-02221
Valve lift:
(A) Thermostat cover 9.0 mm (0.354 in) or more.
(B) Gasket
(C) Thermostat
(A)
(D) Jiggle pin

2) Connect the radiator outlet hose to thermostat

cover.
3) Install the under cover.
(B)
4) Lower the vehicle.
5) Fill with engine coolant. <Ref. to CO(H4SO)-16,
FILLING OF ENGINE COOLANT, REPLACE-
MENT, Engine Coolant.> CO-00033

(A) Thermometer
(B) Thermostat

CO(H4SO)-22
 Radiator
COOLING

7. Radiator 8) Disconnect the ATF cooler hoses from ATF pipe.

(AT model) Plug the openings in the hose and radi-
A: REMOVAL ator with caps in order to prevent ATF from leaking.
1) Set the vehicle on a lift.
2) Disconnect the ground cable from battery.
3) Lift-up the vehicle.
4) Remove the under cover.
5) Drain the engine coolant completely. <Ref. to
CO(H4SO)-16, DRAINING OF ENGINE COOL-
ANT, REPLACEMENT, Engine Coolant.>
6) Disconnect the connectors of radiator main fan
motor (A) and sub fan motor (B).
CO-02250

9) Lower the vehicle.

10) Disconnect the overflow hose.
11) Remove the reservoir tank. <Ref. to
CO(H4SO)-29, REMOVAL, Reservoir Tank.>
12) Remove the air intake duct.
(A)
13) Disconnect the radiator inlet hose from engine.

CO-00224

(B)

CO-02251

14) Remove the radiator upper brackets.

CO-00225

7) Disconnect the radiator outlet hose from water

pump.

CO-00090

15) Detach the power steering hose from clip on ra-

diator.
CO-02249

CO-00037

CO(H4SO)-23
 Radiator
COOLING

16) Lift the radiator up and away from the vehicle. 5) Connect the radiator inlet hose.
B: INSTALLATION
1) Attach the radiator lower cushions to holes on
the radiator lower bracket.

CO-02251

6) Install the air intake duct.

7) Install the reservoir tank.
CO-00041 8) Connect the overflow hose.
9) Lift-up the vehicle.
2) Install the radiator to vehicle.
10) Connect the ATF cooler hoses. (AT model)
NOTE:
Fit the pins on lower side of radiator into the cush-
ions on the body side.
3) Install the radiator upper brackets, and then
tighten the bolts.
Tightening torque:
18 N⋅m (1.8 kgf-m, 13.0 ft-lb)

CO-02250

11) Connect the radiator outlet hose.

CO-00090

4) Attach the power steering hose to radiator.

CO-02249

CO-00037

CO(H4SO)-24
 Radiator
COOLING

12) Connect the connectors to radiator main fan • If engine coolant adheres to the exhaust pipe,
motor (A) and sub fan motor (B). wipe it off completely.
• Be careful to prevent engine coolant from
spurting out when removing the tester.
• Be careful also not to deform the filler neck of
radiator when installing or removing tester.

(A)

CO-00224

(B)

CO-00225

13) Install the under cover.

14) Lower the vehicle.
15) Connect the battery ground cable to battery.
16) Fill engine coolant. <Ref. to CO(H4SO)-16,
FILLING OF ENGINE COOLANT, REPLACE-
MENT, Engine Coolant.>
17) Check the ATF level. <Ref. to 4AT-30, IN-
SPECTION, Automatic Transmission Fluid.>
C: INSPECTION
1) Remove the radiator cap, top off radiator, and
then attach the tester to radiator in place of cap.

CO-00094

2) Apply a pressure of 157 kPa (1.6 kgf/cm2, 23

psi) to the radiator in the follow cases.
(1) Engine coolant leaks at/around radiator.
(2) Engine coolant leaks at/around hoses or
connections.
CAUTION:
• Engine should be turned off.
• Wipe engine coolant from check points in ad-
vance.

CO(H4SO)-25
 Radiator Cap
COOLING

8. Radiator Cap
A: INSPECTION
1) Attach the radiator cap to tester.

CO-00044

2) Increase the pressure until tester gauge pointer

stops. Radiator cap is functioning properly if it holds
the service limit pressure for 5 to 6 seconds.
Standard pressure:
93 — 123 kPa (0.95 — 1.25 kgf/cm2, 14 — 18
psi)
Service limit pressure:
83 kPa (0.85 kgf/cm2, 12 psi)
CAUTION:
Be sure to remove foreign matter and rust from
the cap in advance. Otherwise, results of pres-
sure test will be incorrect.

CO(H4SO)-26
 Radiator Main Fan and Fan Motor
COOLING

9. Radiator Main Fan and Fan C: DISASSEMBLY

Motor 1) Remove the nut which holds the fan onto fan
motor.
A: REMOVAL
1) Set the vehicle on a lift.
2) Disconnect the ground cable from battery.
3) Lift-up the vehicle.
4) Remove the under cover.
5) Disconnect the connector of main fan motor (A).

CO-00047

2) Remove the bolts which install the fan motor

onto shroud.
(A)

CO-00224

6) Remove the ATF hose from clip of radiator main

fan motor assembly. (AT model)
7) Lower the vehicle.
8) Disconnect the overflow hose.
9) Remove the reservoir tank. <Ref. to CO(H4SO)-
29, REMOVAL, Reservoir Tank.>
CO-00048
10) Remove the bolts which secure the radiator
main fan shroud to radiator. D: ASSEMBLY
Assemble in the reverse order of disassembly.
Tightening torque:
4.4 N⋅m (0.45 kgf-m, 3.3 ft-lb)

CO-00096

11) Remove the radiator fan motor assembly.

B: INSTALLATION
Install in the reverse order of removal. CO-00048

NOTE: Tightening torque:

• If it is difficult to install the radiator main fan motor 3.4 N⋅m (0.35 kgf-m, 2.5 ft-lb)
assembly, first loosen the bolts which hold the radi-
ator sub fan motor assembly.
• Refer to COMPONENT for tightening torque.
<Ref. to CO(H4SO)-3, COMPONENT, General De-
scription.>

CO-00047

CO(H4SO)-27
 Radiator Sub Fan and Fan Motor
COOLING

10.Radiator Sub Fan and Fan 2) Remove the nut which holds the fan onto fan
motor.
Motor
A: REMOVAL
1) Set the vehicle on a lift.
2) Disconnect the ground cable from battery.
3) Lift-up the vehicle.
4) Remove the under cover.
5) Disconnect the connector of sub fan motor (B).

CO-00049

3) Remove the bolts which install the fan motor

onto shroud.
(B)

CO-00225

6) Remove the ATF hose from clips of radiator sub

fan motor assembly. (AT model)
7) Lower the vehicle.
8) Remove the air intake duct.
9) Remove the bolts which hold the radiator sub fan CO-00050
shroud to radiator.
D: ASSEMBLY
Assemble in the reverse order of disassembly.
Tightening torque:
4.4 N⋅m (0.45 kgf-m, 3.3 ft-lb)

CO-00101

10) Remove the radiator sub fan motor assembly

through the under side of vehicle.
B: INSTALLATION
CO-00050
Install in the reverse order of removal.
NOTE: Tightening torque:
Refer to COMPONENT for tightening torque. <Ref. 3.4 N⋅m (0.35 kgf-m, 2.5 ft-lb)
to CO(H4SO)-3, COMPONENT, General Descrip-
tion.>
C: DISASSEMBLY
1) Remove the clip which holds the motor connec-
tor onto shroud.

CO-00049

CO(H4SO)-28
 Reservoir Tank
COOLING

11.Reservoir Tank
A: REMOVAL
1) Disconnect the overflow hose from the radiator
filler neck position.
2) While pressing the pawl (A), remove the reser-
voir tank by pulling in the direction of arrow.

(A)

CO-00226

B: INSTALLATION
Install in the reverse order of removal.
C: INSPECTION
Make sure the engine coolant level is between
“FULL” and “LOW”.

CO(H4SO)-29
 Engine Cooling System Trouble in General
COOLING

12.Engine Cooling System Trouble in General

A: INSPECTION
Trouble Possible cause Corrective action
Replenish the engine coolant, inspect for leakage, and
a. Insufficient engine coolant
repair.
b. Loose timing belt Repair or replace the timing belt tensioner.
c. Oil on timing belt Replace.
d. Malfunction of thermostat Replace.
e. Malfunction of water pump Replace.
f. Clogged engine coolant passage Clean.
Inspect and repair the ignition control system.
g. Improper ignition timing <Ref. to EN(H4SO)(diag)-2, Basic Diagnostic Proce-
dure.>
Over-heating h. Clogged or leaking radiator Clean or repair, or replace.
i. Improper engine oil in engine coolant Replace the engine coolant.
Inspect and repair the fuel injection system.
j. Air/fuel mixture ratio too lean <Ref. to EN(H4SO)(diag)-2, Basic Diagnostic Proce-
dure.>
k. Excessive back pressure in exhaust system Clean or replace.
l. Insufficient clearance between piston and cylinder Adjust or replace.
m. Slipping clutch Repair or replace.
n. Dragging brake Adjust.
Inspect the radiator fan relay, engine coolant tempera-
o. Malfunction of radiator fan
ture sensor or radiator motor and replace them.
a. Atmospheric temperature extremely low Partly cover the radiator front area.
Over-cooling
b. Defective thermostat Replace.
a. Loosened or damaged connecting units on hoses Repair or replace.
b. Leakage from water pump Replace.
c. Leakage from water pipe Repair or replace.
Engine coolant d. Leakage around cylinder head gasket Retighten the cylinder head bolts or replace gasket.
leaks e. Damaged or cracked cylinder head and cylinder
Repair or replace.
block
f. Damaged or cracked thermostat case Repair or replace.
g. Leakage from radiator Repair or replace.
a. Defective timing belt Replace.
b. Defective radiator fan Replace.
Noise
c. Defective water pump bearing Replace the water pump.
d. Defective water pump mechanical seal Replace the water pump.

CO(H4SO)-30