Symptoms | Possible Causes | Remedy | ||
Coolant leakage | ● From the thermostat gasket | Check the mounting bolts | ● Check the torque of the mounting bolts | ● Retighten the bolts and check leakage again. |
Check the gasket for damage | ● Check gasket or seal for damage | ● Replace gaskets and reuse the thermostat. | ||
Cooled excessively | ● Low heater performance (cool air blowed-out) ● Thermogauge indicates 'LOW' | Visually check after removing the radiator cap. | ● Insufficient coolant or leakage. | ● After refilling coolant, recheck. |
GDS check＆Starting engine | ● Check DTCs ● Check connection of the fan clutch or the fan motor. ※ If the fan clutch is always connected, there will be a noise at idle. | ● Check the engine coolant sensor, wiring and connectors. ● Replace the componants. | ||
Remove the thermostat and inspect | ● Check if there are dusts or chips in the thermostat valve. ● Check adherence of the thermostat. | ● Clean the thermostat valve and reuse the thermostat. ● Replace the thermostat, if it doesn't work properly. | ||
Heated excessively | ● Engine overheated ● Thermogauge indicates 'HI' | Visually check after removing the radiator cap. | ● Insufficient coolant or leakage. ※ Be careful when removing a radiator cap of the overheated vehicle. ● Check air in cooling system. | ● After refilling coolant, recheck. ● Check the cylinder head gaskets for damage and the tightening torque of the mounting bolts. |
GDS check＆Starting engine | ● Check DTCs ● Check the fan motor performance as temperature varies. ● Check if the fan clutch slips. ● Check the water pump adherence or impeller damaged. | ● Check the engine coolant sensor, wiring and connectors. ● Check the fan motor, the relay and the connector. ● Replace the fan clutch, if it doesn't work properly. ● Replace the water pump, if it doesn't work properly. | ||
Immerse the thermostat in boiling water and inspection. | ● After removing the thermostat, check it works properly. ※ Check the thermostat opens at the valve opening temperature. | ● Replace the thermostat, if it doesn't work properly. | ||
