Kia Forte BD Quiz
Engine Mechanical System

Thermostat

In this manual: Engine Mechanical System
General Information — 8Maintenance — 32Engine Mechanical System — 47Engine Electrical System — 17Emission Control System — 10Engine Control System/Fuel System — 32Clutch System — 11Manual Transmission — 11DCT (Dual Clutch Transmission) System — 16Drive Shaft and Axle — 8Suspension System — 26Steering — 9Restraints — 11Brake System — 27Body (Interior and Exterior) — 119Body Electrical System — 98Heating, Ventilation, and Air Conditioning — 27
10steps
~60min
3/5difficulty
0102030405023.517N·mlb·ft
Tightening torque found on this page
Done 0 of 10

Components and Component Location

Components

1. Water Inlet Pipe 2. Thermostat

Repair Procedures

Removal

  1. Drain the engine coolant.

    (Refer to Cooling System - "Engine Coolant")

  2. Remove the lower radiator hose (A).

  3. Remove the water outlet (A).

    Tightening torque: 18.6 – 24 N·m

  4. Remove the thermostat (A).

  5. Install in the reverse order of removal.

  6. Fill the engine coolant.

    (Refer to Cooling System - "Engine Coolant")

  7. Start the engine and check for leaks.

Inspection

  1. Immerse the thermostat in water heated above 95 °C, then heat for at least 3 minutes to check valve lift.

  2. Check the valve opening temperature.

    Valve opening temperature:

    82±1.5°C (179.6±2.7°F)

    Fully open temperature:

    95°C (203°F)

    If the valve opening temperature does not meet the specification, replace the thermostat.

  3. Check the valve lift.

    Valve lift: 8 mm (0.3 in) or more at 100 °C

    If the valve lift is not as specified, replace the thermostat.

Troubleshooting

Troubleshooting

Symptoms Possible Causes Remedy
Coolant Leakage

  • From the thermostat gasket

 Check the mounting bolts

  • Check the tightening torque of the mounting bolts

  • Tighten the bolts and check for leaks again.
Check the gasket for damage

  • Check the gasket or seal for damage

  • Replace the gaskets and reuse the thermostat.
Excessive cooling

  • Insufficient heater output (cold air blows out)

  • Temperature gauge indicates "LOW"

 Visually check after removing the radiator cap.

  • Insufficient coolant or leakage.

  • After adding coolant, repeat the check.
KDS Check and Engine Start

  • Check the diagnostic trouble codes

  • Check the connection of the fan clutch or fan motor.

※ If the fan clutch is always engaged, noise will be heard at idle.

  • Check the engine coolant temperature sensor, wiring and connectors.

  • Replace the components.
Remove the thermostat and inspect.

  • Check for dust or debris in the thermostat valve.

  • Check the thermostat seating.

  • Clean the thermostat valve and reuse the thermostat.

  • Replace the thermostat if it does not operate properly.
Overheating

  • Engine Overheated

  • Temperature gauge indicates "HI"

 Visually check after removing the radiator cap.

  • Insufficient coolant or leakage.

    ※ Be careful when removing the radiator cap from an overheated vehicle.

  • Check for air in the cooling system.

  • After adding coolant, repeat the check.

  • Check the cylinder head gasket for damage and the tightening torque of the mounting bolts.
KDS Check and Engine Start

  • Check the diagnostic trouble codes

  • Check the operation of the fan motor as the temperature changes.

  • Check whether the fan clutch is slipping.

  • Check the water pump for proper fit or damaged impeller.

  • Check the engine coolant temperature sensor, wiring and connectors.

  • Check the fan motor, relay and connector.

  • Replace the fan clutch if it does not operate properly.

  • Replace the water pump if it does not operate properly.
Immerse the thermostat in boiling water and inspect it.

  • After removing the thermostat, check its operation.

※ Make sure the thermostat opens at the valve opening temperature.

  • Replace the thermostat if it does not operate properly.

Test yourself

A quick Kia Forte BD quiz: every answer comes with an explanation and a link to the manual page.