1F-4 Engine Cooling System:
Engine Cooling Symptom Diagnosis
Condition
Engine overheats
Engine over cools
Cooling Circuit Inspection
WARNING
!
• Do not open the radiator cap when the
engine is hot, as you may be injured by
escaping hot liquid or vapor.
• When removing the radiator cap tester, put
a rag on the filler to prevent the engine
coolant from spraying out.
Inspect the cooling circuit in the following procedures:
1) Remove the right frame body cover. Refer to
"Exterior Parts Removal and Installation in Section
9D (Page 9D-4)".
2) Remove the radiator cap (1) and connect the
radiator tester (2) to the filler.
3) Pressurize the cooling system with 120 kPa (1.2 kgf/
cm, 17 psi) of pressure, and then check if it holds the
pressure for 10 seconds.
CAUTION
!
Do not exceed the radiator cap release
pressure, or the radiator cap and
subsequently the radiator, can be damaged.
Diagnostic Information and Procedures
Possible cause
Not enough engine coolant.
Radiator core clogged with dirt or scale. Clean.
Faulty cooling fan.
Defective cooling fan relay, or open-or-
short circuited.
Clogged engine coolant passage.
Air trapped in the cooling circuit.
Defective water pump.
Use of incorrect engine coolant.
Defective thermostat.
Defective ECT sensor.
Defective ECM.
Defective cooling fan relay, or open-or-
short circuited.
Extremely cold weather.
Defective thermostat.
Defective ECT sensor.
Defective ECM.
Repair Instructions
B944H11606001
Correction / Reference Item
Add engine coolant.
Repair or replace.
Repair or replace.
Clean.
Bleed air.
Replace.
Replace.
Replace.
Replace.
Replace.
Repair or replace.
Put on radiator cover.
Replace.
Replace.
Replace.
1
4) After finishing the cooling circuit inspection, reinstall
the removed parts.
B944H11604001
I944H1160002-01
2
I933H1160003-02