Section 03
ENGINE
Subsection 02
(TROUBLESHOOTING)
VMR2004_125_03_02A.FM
03-02-1
TROUBLESHOOTING
0
The following charts are provided to help in diagnosing the probable source of troubles. It should be used
as a guideline. This section pertains to engine mechanical components only. Some related problems can
come from other systems such as ignition system, fuel system, etc. and have an impact on the engine.
Ensure to check the other systems prior to concluding that the engine is in fault.
COOLING SYSTEM
SYMPTOM
HIGH ENGINE OPERATING TEMPERATURE.
CONDITION
NORMAL USE.
Test/Inspection
1. Check coolant level.
a. Coolant less than recommended level.
Refill.
2. Check temperature sensor for electrical/mechanical failure.
a. Temperature sensor defective.
Replace.
3. Check thermostat.
a. Thermostat defective.
Replace.
4. Check gasket(s) underneath water pump cover.
a. Leakage in water pump cover area.
Retighten screws and/or replace gasket.
5. Check leak indicator hole (water pump housing area MAG side) if coolant leaks.
a. Coolant leaking from leak indicator hole means a damaged rotary seal inside mag-
neto cover.
Replace both rotary seal and oil seal (refer to COOLING SYSTEM and MAGNETO
SYSTEM).
6. Check coolant bleeding screw on thermostat housing.
a. Screw is loosed/missing and/or gasket ring is missing/broken.
Retighten/add screw and replace gasket ring.
7. Check condition of hoses and hose clamps fixation.
a. Hoses are brittle and/or hard.
Replace.
b. Hose clamps are loose.
Retighten clamps.
8. Check condition of impeller located on the water pump shaft.
a. Impeller wings broken and/or impeller thread is damaged.
Replace.
9. Check coolant drain screw on water pump housing MAG side (marked “Drain”).
a. Copper ring on drain screw leaks.
Retighten screw and/or replace copper gasket ring.