Subaru Legacy IV (2008 year). Manual - part 292

CO(H4DOTC)-30

Coolant Filler Tank

COOLING

11.Coolant Filler Tank

A: REMOVAL

WARNING:
The radiator is pressurized. Wait until engine
cools down before working on the radiator.
1) Remove the collector cover.
2) Drain approximately 3.0 

2 (3.2 US qt, 2.6 Imp

qt) of coolant. <Ref. to CO(H4DOTC)-14, DRAIN-
ING OF ENGINE COOLANT, REPLACEMENT,
Engine Coolant.>
3) Disconnect the engine coolant hoses from cool-
ant filler tank.
4) Remove the bolts which install the coolant filler
tank.

5) Disconnect the engine coolant hose which con-
nects the under side of coolant filler tank.
6) Remove the coolant filler tank.

B: INSTALLATION

Install in the reverse order of removal.

Tightening torque:

16 N·m (1.6 kgf-m, 11.8 ft-lb)

CO-02392

CO-02393

CO(H4DOTC)-31

Engine Cooling System Trouble in General

COOLING

12.Engine Cooling System Trouble in General

A: INSPECTION

Trouble

Possible cause

Corrective action

Overheating

a. Insufficient engine coolant

Replenish engine coolant, inspect for leakage, and 
repair it if necessary.

b. Loose timing belt

Repair or replace timing belt tensioner.

c. Oil on drive belt

Replace.

d. Malfunction of thermostat

Replace.

e. Malfunction of water pump

Replace.

f. Clogged engine coolant passage

Clean.

g. Improper ignition timing

Inspect and repair ignition control system. <Ref. to 
EN(H4DOTC)(diag)-2, PROCEDURE, Basic Diagnos-
tic Procedure.>

h. Clogged or leaking radiator

Clean, repair or replace.

i. Engine oil mixed in engine coolant

Replace engine coolant. If there is no improvement, 
check, repair and replace the engine.

j. Air/fuel mixture ratio too lean

Inspect and repair the fuel injection system. <Ref. to 
EN(H4DOTC)(diag)-2, PROCEDURE, Basic Diagnos-
tic Procedure.>

k. Excessive back pressure in exhaust system

Clean or replace.

l. Insufficient clearance between piston and cylin-
der

Adjust or replace.

m. Slipping clutch

Repair or replace.

n. Dragging brake

Adjust.

o. Defective radiator fan

Inspect the radiator fan relay, engine coolant tempera-
ture sensor or fan motor and replace them.

Over-cooling

a. Ambient temperature extremely low

Partly cover radiator front area.

b. Defective thermostat

Replace.

Engine coolant 
leaks

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.

d. Leakage around cylinder head gasket

Retighten cylinder head bolts or replace gasket.

e. Damaged or cracked cylinder head and cylinder 
block

Repair or replace.

f. Damaged or cracked thermostat cover

Repair or replace.

g. Leakage from radiator

Repair or replace.

Noise

a. Timing belt problem

Replace.

b. Defective radiator fan

Replace.

c. Defective water pump bearing

Replace water pump.

d. Defective water pump mechanical seal

Replace water pump.

CO(H4DOTC)-32

Engine Cooling System Trouble in General

COOLING

LU(H4DOTC)-2

General Description

LUBRICATION

1. General Description

A: SPECIFICATION

Specifications for the turbo model are included in
the LU (H4SO) section. <Ref. to LU(H4SO)-2, Gen-
eral Description.>