Kia Cadenza YG: 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 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.

    Removal     Removal of the thermostat would have an adverse effect, causing a lowering of cooling efficiency. Do not remove the thermostat, even if the engine tends to overheat.

    Other information:

    Kia Cadenza YG 2016-2021 Service Manual: A/C Pressure Transducer Description and Operation

    Description A/C pressure transducer convert the pressure value of high pressure line into voltage value after measure it. By converted voltage value, engine ECU controls cooling fan by operating it high speed or low speed. Engine ECU stop the operation of compressor when the temperature of refrigerant line is so high or so low irregularl

    Kia Cadenza YG 2016-2021 Service Manual: Photo Sensor Description and Operation

    Description 1. The photo sensor is located at the center of defrost nozzle. 2. The photo sensor contains a photovoltaic (sensitive to sunlight) diode. The solar radiation received by its light receiving portion, generates an electromotive force in proportion to the amount of radiation received which is transferred to the automatic tem

    Categories

     
    Copyright © 2026 www.kcadenzavg.com - 0.0275