Location of thermostat cover on 4-cylinder models
The thermostat cover on 4-cylinder models is located behind the water pump.
The location of the thermostat housing in 6-cylinder models
thermostat housing (indicated by an arrow) located behind the intake manifold above the gearbox.
General check
1. Measure the coolant level, check the tension of the drive belt and the operation of the temperature sensor.
2. If the engine takes too long to warm up, the thermostat is most likely stuck open. Replace thermostat.
3. If the engine is overheating, check the temperature of the upper radiator hose, if the hose is not hot, then the thermostat is stuck in the closed position. Replace thermostat.
Thermostat check
1. For a more thorough check, the thermostat must be removed from the engine.
2. If the thermostat does not close at room temperature, it is defective and must be replaced.
3. Dip the thermostat in a container of cold water (thermostat closed).
4. Heat the water in the container and monitor its temperature. The thermostat must not touch the walls and bottom of the container.
5. Record the thermometer reading when the thermostat is just starting to open and when it is fully open. Compare the obtained values with the technical requirements.
6. Replace the thermostat if it does not open or close or is stuck in any position.
Replacement
1. Disconnect the negative battery cable.
2. Drain the coolant from the radiator. Disconnect the radiator hose from the thermostat housing or from the inlet pipe.
3. On 4-cylinder engines, disconnect the intake pipe from the thermostat housing. Remove the oil filter for better access.
4. In 6-cylinder engines air valve cover and screw nuts (indicated by arrows) at the back of the engine. Slide the wires to access the thermostat cover bolts.
5. Disconnect intake tube (arrow) from the cylinder head and disconnect the tube from the thermostat housing (6-cylinder models).
6. Disconnect from a casing of the thermostat of fastening and a wire and remove a casing.
7. Remove the thermostat from the casing.
8. Clean the mating surfaces and install a new gasket.
9. Install the thermostat and thermostat housing in the reverse order of removal.