| SONATA(YF) >2012 > G 2.4 GDI > Engine Mechanical System > Cooling System > Thermostat>Troubleshooting |

Troubleshooting

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 blows-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 the fan motor performance as temperature varies.

• | 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.

• | Check the fan motor, the relay and the connector.

• | 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.