Thermostat (6, fig. 4.16) built into the pump housing and can be replaced separately from it.
The replacement of the thermostat must be carried out in the following order.
Remove the upper part of the air filter housing together with the air mass meter, the stiffening plate, the fan shroud and the fan drive coupling with the impeller.
Drain the coolant and send it for recycling. Disconnect the coolant hose and connector (10) from the thermostat housing.
Loosen the bolts (8) fixing the cover of the thermostat housing and remove it together with the built-in thermostat. Check thermostat operation.
Clean the seating surfaces on the thermostat housing and coolant pump flange to remove dirt and traces of oil. Replace o-ring (7).
When installing the thermostat, tighten the bolts securing its cover to a torque of 10 Nm (1.0 kgf·m). Replace gasket and tighten bolt (M14x1.5) drain hole on the cylinder block with a torque of 25 Nm (2.5 kgf·m).
Install the stiffening board. Fill the engine cooling system, bleed the air from the cooling system and check for leaks. If leaks are found, slightly tighten the mounting bolts.
Check the operation of the viscous coupling (turning on the fan), whether the temperature has risen in the lower part of the radiator and whether the thermostat housing is sealed.