Subaru 2003 Legacy User manual

FUJI HEAVY INDUSTRIES LTD. G2300GE4
2003 LEGACY SERVICE MANUAL QUICK REFERENCE INDEX
ENGINE SECTION 3
This service manual has been prepared
to provide SUBARU service personnel
with the necessary information and data
for the correct maintenance and repair
of SUBARU vehicles.
This manual includes the procedures
for maintenance, disassembling, reas-
sembling, inspection and adjustment of
components and diagnostics for guid-
ance of experienced mechanics.
Please peruse and utilize this manual
fully to ensure complete repair work for
satisfying our customers by keeping
their vehicle in optimum condition.
When replacement of parts during
repair work is needed, be sure to use
SUBARU genuine parts.
All information, illustration and specifi-
cations contained in this manual are
based on the latest product information
available at the time of publication
approval.
FUEL INJECTION (FUEL SYSTEMS) FU(H4DOSTC)
EMISSION CONTROL
(AUX. EMISSION CONTROL DEVICES) EC(H4DOSTC)
INTAKE (INDUCTION) IN(H4DOSTC)
MECHANICAL ME(H4DOSTC)
EXHAUST EX(H4DOSTC)
COOLING CO(H4DOSTC)
LUBRICATION LU(H4DOSTC)
SPEED CONTROL SYSTEMS SP(H4DOSTC)
IGNITION IG(H4DOSTC)
STARTING/CHARGING SYSTEMS SC(H4DOSTC)
ENGINE (DIAGNOSTICS) EN(H4DOSTC)

COOLING CO(H4DOSTC)
Page
1. General Description ....................................................................................2
2. Radiator Main Fan System..........................................................................7
3. Radiator Sub Fan System.........................................................................11
4. Engine Coolant..........................................................................................15
5. Water Pump..............................................................................................17
6. Thermostat................................................................................................21
7. Radiator.....................................................................................................23
8. Radiator Cap.............................................................................................27
9. Radiator Main Fan and Fan Motor............................................................28
10. Radiator Sub Fan and Fan Motor..............................................................30
11. Reservoir Tank..........................................................................................32
12. Coolant Filler Tank....................................................................................33
13. Engine Cooling System Trouble in General..............................................34

CO(H4DOSTC)-2
COOLING GENERAL DESCRIPTION
1. General Description
A: SPECIFICATIONS
Cooling system Electric fan + Forced engine coolant circulation sys-
tem
Total engine coolant capacity 2(US qt, Imp qt) MT: Approx. 7.7 (8.1, 6.8)
AT: Approx. 7.6 (8.0, 6.7)
Water pump
Type Centrifugal impeller type
Discharge performance I
Discharge 20 2(5.3 US gal, 4.4 Imp gal)/min.
Pump speed—Discharge pres-
sure (pressure leak) 760 rpm —2.9 kPa [0.3 mAq (1.0 ftAq)]
Engine coolant temperature 85°C (185°F)
Discharge performance II
Discharge 100 2(26.4 US gal, 22.0 Imp gal)/min.
Pump speed—Discharge pres-
sure (pressure leak) 3,000 rpm —49.0 kPa [5.0 mAq (16.4 ftAq)]
Engine coolant temperature 85°C (185°F)
Discharge performance III
Discharge 200 2(52.8 US gal, 44.0 Imp gal)/min.
Pump speed—Discharge pres-
sure (pressure leak) 6,000 rpm —225.4 kPa [23.0 mAq (75.5 ftAq)]
Engine coolant temperature 85°C (185°F)
Impeller diameter 76 mm (2.99 in)
Number of impeller vanes 8
Pump pulley diameter 60 mm (2.36 in)
Clearance between impel-
ler and case Standard 0.5 —0.7 mm (0.020 —0.028 in)
Limit 1.0 mm (0.039 in)
“Thrust”runout of impeller end 0.5 mm (0.020 in)
Thermostat
Type Wax pellet type
Starts to open 76 —80°C (169 —176°F)
Fully opened 91°C (196°F)
Valve lift 9.0 mm (0.354 in) or more
Valve bore 35 mm (1.38 in)
Radiator fan Motor 75 W (main fan)
75 W (sub fan)
Fan diameter ×Blade 300 mm (11.81 in) ×5 (main fan)
300 mm (11.81 in) ×4 (sub fan)
Radiator
Type Down flow, pressure type
Core dimensions 691.5 ×340 ×16 mm
(27.22 ×13.39 ×0.63 in)
Pressure range in which cap valve is open or closed
Above: 108±15 kPa
(1.1±0.15 kg/cm2, 16±2 psi)
Below: −1.0 to −4.9 kPa
(−0.01 to −0.05 kg/cm2, −0.1 to −0.7 psi)
Fins Corrugated fin type
Reservoir
tank Capacity 0.5 2(0.5 US qt, 0.4 Imp qt)

CO(H4DOSTC)-3
COOLING
GENERAL DESCRIPTION
B: COMPONENT
1. WATER PUMP
(1) Thermostat case (5) Gasket Tightening torque: N·m (kgf-m, ft-lb)
(2) Gasket (6) Heater by-pass hose T1: First 12 (1.2, 8.7)
Second 12 (1.2, 8.7)
(3) Thermostat (7) Coolant filler tank by-pass hose
(4) Water pump ASSY (8) Water by-pass hose T2: 6.5 (0.66, 4.8)
( 1 )
( 2 )
( 3 )
( 4 )
( 5 )
( 6 ) ( 7 )
T2
( 8 )
T2
T2
T1
T1
CO-00201

CO(H4DOSTC)-4
COOLING GENERAL DESCRIPTION
2. RADIATOR AND RADIATOR FAN
(1) Radiator lower cushion (14) Radiator main fan and main fan
motor ASSY (25) ATF outlet hose B (AT vehicles only)
(2) Radiator
(3) Radiator upper cushion (15) Radiator outlet hose (26) ATF inlet hose B (AT vehicles
only)
(4) Radiator upper bracket (16) Radiator drain plug
(5) Clamp (17) Engine coolant filler tank (27) ATF pipe (AT vehicles only)
(6) Radiator inlet hose (18) Engine coolant filler tank cap
(7) Engine coolant reservoir tank cap (19) Engine coolant hose Tightening torque: N·m (kgf-m, ft-lb)
(8) Overflow hose (20) Radiator lower bracket T1: 3.4 (0.35, 2.5)
(9) Engine coolant reservoir tank (21) O-ring T2: 4.4 (0.45, 3.3)
(10) Overflow pipe (22) ATF hose clamp (AT vehicles
only) T3: 4.9 (0.50, 3.6)
(11) Sub fan shroud T4: 18 (1.8, 13.0)
(12) Radiator sub fan and sub fan
motor ASSY (23) ATF outlet hose A (AT vehicles only) T5: 12 (1.2, 8.7)
(13) Main fan shroud (24) ATF inlet hose A (AT vehicles
only)
CO-00145
T3 (7)
(18)
(17)
(5)
(5) (19)
(9)
T3
T3
T5
T2
T2
T1
(13)
(11)
(14)
(5)
(5)
(6)
(8)
T4
(5)
(15)
(1)
(2)
(20)
(16)
(3)
(4)
(10 )
(21)
(12)
T1
(24)
(25)
(22)
(22)
(22)
(22)
(22)
(22)
T5
(26)
(27)
(23)

CO(H4DOSTC)-5
COOLING
GENERAL DESCRIPTION
C: CAUTION
•Wear working clothing, including a cap, protec-
tive goggles, and protective shoes during opera-
tion.
•Remove contamination including dirt and corro-
sion before removal, installation or disassembly.
•Keep the disassembled parts in order and pro-
tect them from dust or dirt.
•Before removal, installation or disassembly, be
sure to clarify the failure. Avoid unnecessary re-
moval, installation, 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.
•Placeshopjacksorsafetystandsatthespecified
points.
•Before disconnecting electrical connectors of
sensors or units, be sure to disconnect ground ca-
ble from battery.

CO(H4DOSTC)-6
COOLING GENERAL DESCRIPTION
D: PREPARATION TOOL
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
499977100 (MT
model) CRANK PULLEY WRENCH Used for fixing crankshaft pulley when loos- ening and tightening crankshaft pulley bolts.
499977400 (AT
model) CRANK PULLEY WRENCH Used for fixing crankshaft pulley when loos- ening and tightening crankshaft pulley bolts.
18231AA010 CAMSHAFT
SPROCKET
WRENCH
•Used for removing and installing camshaft
sprocket. (Intake side)
•Camshaft sprocket wrench (499207100) is
also available.
499207400 CAMSHAFT
SPROCKET
WRENCH
Used for removing and installing camshaft
sprocket. (Exhaust side)
ST-499977100
ST-499977400
ST18231AA010
ST-499207400

CO(H4DOSTC)-7
COOLING
RADIATOR MAIN FAN SYSTEM
2. Radiator Main Fan System
A: SCHEMATIC
CO-00146
2 1 4 3
21 22 24 20
8
7
5 9
20A
20A
SUB FAN
RELAY
AIR CONDITIONING RELAY HOLDER
SUB FAN
MOTOR
MAIN FAN
MOTOR
MAIN FAN
RELAY
F28
F16
F66 F27
1 2
F17
B100 F2
B72
1 2
8
9
NO. 3
NO. 18
NO. 17
SBF-4
SBF-1
IGNITION
SWITCH
B72
34
12
B137
BATTERY
17 28
B137
ECM
F16 F17
2 1
F27
1 2
3 4
5 6 7
8
9
11
10
13
12 14 21
20
23
22 24 31
30
33
32 34
1615 17
18
19
2625 27
28
29
35
36
F66 F28
F2
12 3 4 5 6 7
9 10 11 12 13 14 15 16
8127895634
101112192021 293031 1314151617 2728 18 2223242526

CO(H4DOSTC)-8
COOLING RADIATOR MAIN FAN SYSTEM
B: INSPECTION
DETECTING CONDITION:
Condition:
•Engine coolant temperature is above 95°C (203°F).
•Vehicle speed is below 19 km/h (12 MPH).
TROUBLE SYMPTOM:
•Radiator main fan does not rotate under the above conditions.
Step Value Yes No
1 CHECK POWER SUPPLY TO MAIN FAN MO-
TOR.
CAUTION:
Be careful not to overheat engine during re-
pair.
1) Turn ignition switch to OFF.
2) Disconnect connector from main fan motor.
3) Start the engine, and warm it up until
engine coolant temperature increases over
95°C (203°F).
4) Stop the engine and turn ignition switch to
ON.
5) Measure voltage between main fan motor
connector and chassis ground.
Connector & terminal
(F17) No. 2 (+) — Chassis ground (
−
−−
−
):
Does the measured value exceed the spec-
ified value?
10 V Go to step 2. Go to step 5.
2 CHECK GROUND CIRCUIT OF MAIN FAN
MOTOR.
1) Turn ignition switch to OFF.
2) Measure resistance between main fan
motor connector and chassis ground.
Connector & terminal
(F17) No. 1 — Chassis ground:
Is the measured value less than the speci-
fied valve?
5 ΩGo to step 3. Repairopencircuit
in harness
between main fan
motor connector
and chassis
ground.
3 CHECK POOR CONTACT.
Check poor contact in main fan motor connec-
tor.
Is there poor contact in main fan motor con-
nector?
There is poor contact. Repair poor con-
tact in main fan
motor connector.
Go to step 4.
4 CHECK MAIN FAN MOTOR.
Connect battery positive (+) terminal to termi-
nal No. 2, and negative (−) terminal to terminal
No. 1 of main fan motor connector.
Does the main fan rotate?
The main fan rotates. Repair poor con-
tact in main fan
motor connector.
Replace main fan
motor with a new
one.
5 CHECK POWER SUPPLY TO MAIN FAN RE-
LAY.
1) Turn ignition switch to OFF.
2) Remove main fan relay from A/C relay
holder.
3) Measure voltage between main fan relay
terminal and chassis ground.
Connector & terminal
(F66) No. 8 (+) — Chassis ground (
−
−−
−
):
Does the measured value exceed the spec-
ified value?
10 V Go to step 6. Go to step 7.