Removing
Drain the coolant and collect it.
Disconnect the thick hose going to the radiator and the thin hose going to the expansion tank from the thermostat housing. To do this, compress the spring clamps with pliers.
Loosen the mounting bolts and remove the coolant outlet fitting together with the gasket and thermostat. Pay attention to the installation position (see picture) and, if necessary, tag it.
Installation
If necessary, test the thermostat by heating it in a container of water before reinstalling.
Clean and degrease the sealing surfaces of the outlet fitting and thermostat housing.
Insert the thermostat into the cylinder head in the same position as before removal. The rubber gasket around the thermostat should only be replaced if damaged.
Install the thermostat housing with a new gasket and tighten the mounting bolts to 20 Nm. In each case, replace the gasket.
Slide the coolant hoses onto the thermostat housing and secure with clamps.
Pour coolant into the cooling system. Warm up the engine and check the tightness of the connection of the outlet fitting and, if necessary, tighten the bolts.
Special for 1.25/1.4L engine
Attention: Only the differences are described here, which you need to pay attention to when removing the thermostat.
Remove generator.
Remove the coolant hoses from the thermostat housing, to do this, compress the spring clamps, hoses with pliers. The thermostat housing is located on the cylinder head next to the oil dipstick.
Insert the thermostat so that the small hole (arrow) was at the top.
Install the thermostat housing with a new gasket and tighten the mounting bolts to 10 Nm. Do not exceed the tightening torque, otherwise the housing will be damaged.
Especially for diesel engine
Attention: Only the differences are described here, which you need to pay attention to when removing the thermostat.
Remove the coolant hose going to the radiator from the thermostat housing. To do this, compress the spring clamp with pliers.
Unplug the temperature sensor wire at the top of the thermostat housing.
Unscrew the two mounting bolts and remove the housing with gasket and thermostat.