Kia Optima: Thermostat. Troubleshooting - Engine Mechanical System - Kia Optima TF 2011-2026 Service ManualKia Optima: 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.


Inspection
1. Immerse the thermostat in water and gradually heat the water. 2. Check the valve opening temperature. Valve opening temperature: 82 ± 1.5°C ( ...

Lubrication System
...

See also:

Using SIRIUS® Satellite Radio
Activation In order to extend or reactivate your subscription to SIRIUS® Satellite Radio, you will need to contact SIRIUS® Customer Care at 1-888-539-7474. Have your 12 digit SID (Sirius® Id ...

Installation
1. Installation is the reverse of removal. After replacement or reinstallation procedure of the valve body assembly, ...

Air conditioning
Press the A/C button to turn the air conditioning system on (indicator light will illuminate). Press the button again to turn the air conditioning system off. ...

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