Attention! If the engine heats up after the vehicle has traveled a short distance, this may be due to the fact that the radiator is clogged with lime deposits.
As the engine warms up, the thermostat opens a large coolant circuit. If the coolant thermostat is closed due to a malfunction, the engine gets too hot. This can be determined by the coolant temperature display, which is in the red range, while at the same time the radiator remains cold. But a faulty thermostat, even after the coolant has cooled down, may remain open further. This can be seen from the fact that the engine no longer reaches its operating temperature, or the coolant temperature indicator needle moves up more slowly than before, or the heating power is reduced in winter.
Examination
1. Remove the coolant temperature control.
2. Measure the height of the thermostat, write down the size "A".
3. Slowly heat the thermostat in the water bath. At the same time, it should not come into contact with the walls of the vessel, but is completely immersed in water. Check the temperature with a suitable thermometer. At about 87°C the regulator's bimetallic plate begins to elongate, reaching its maximum elongation at about 102°C.
4. Heat the water in the bath until it boils. Remove the thermostat, measure the height (size "b") and compare with the first measured value (size "A"). At the end of the opening, the opening lift is approximately 8 mm. Since this temperature is not reached, check if the regulator has opened to a comparable size, otherwise replace it.
5. Finally, check if the regulator closes completely again when it cools down, otherwise replace the regulator.
6. Replace the thermostat if it does not function properly.
7. Reinstall the thermostat.
4-cylinder petrol engine
1. Bolt; 2. Coolant hose; 3. Coolant hose; 27. Cover of the coolant thermostat housing 27a. Coolant thermostat; 29. O-ring; 30. Seal
Removing
1. Disconnect the ground wire (–) from the battery.
Attention! This erases the anti-theft code of the radio.
2. Drain the coolant into a suitable container.
3. Remove the front plastic cover.
4. Remove both coolant hoses from the thermostat cover, first loosen the clamps and slide them back.
5. Remove the screws from the thermostat cover.
6. Remove the thermostat cover together with the thermostat.
Attention! The thermostat must not be separated from the cover, otherwise it will be damaged and cannot be reinstalled.
7. Check thermostat.
Installation
1. Fit the cover together with the thermostat and a new O-ring and screw it in with a torque of 10 Nm. Clean the sealing surfaces on the body and cover in advance.
2. Fit the air outlet hose and coolant hose and secure with clips.
3. Fill with coolant.
4. Let the engine warm up until the fan turns on. Check if the bottom of the radiator is getting warm and if the thermostat housing is tight.
5. Connect the ground wire to the battery. Set the time on the clock. Set the radio's anti-theft code.
Features of the 6-cylinder engine
1. Unscrew the thermostat cover and set it aside with the connected hose. Pull out the thermostat.
2. Insert the thermostat with a new O-ring into the housing.
Attention! When the coolant is filled, air is removed from the cooling system through the ball valve on the thermostat. Therefore, insert the thermostat in such a way that the ball valve is at its highest point.
3. Fit the cover and screw it in with a torque of 10 Nm.
Diesel engine
Diesel engine 2.2/2.5L
6. Air hose; 17. Thermostat cover; 18. Bolt M 6 x 25 19. O-ring; 20. Coolant regulator (thermostat)
Removing
1. Disconnect the ground wire from the battery.
Attention! This erases the anti-theft code of the radio.
2. Drain the coolant into a clean receiving vessel.
3. Remove the air hose by loosening its clamps.
4. Unscrew thermostat cap on water pump and lay aside with hose connected.
5. Remove the thermostat.
Installation
1. Insert the thermostat with a new O-ring into the cover. In this case, the rib on the cover engages in the groove of the coolant regulator.
2. Fit the cover with the regulator and tighten it tightly with a torque of 10 Nm.
3. Fill with coolant.
4. Let the engine warm up until the fan turns on. Check if the radiator is warming up below and if the thermostat housing is tight. Connect the ground wire to the battery terminal.
5. Connect the ground wire to the battery terminal.
6. Set the time on the clock.
7. Enter the radio's anti-theft code.