Caution: If the engine overheats after a short trip, the cause may be lime deposits in the radiator.
Four cylinder engine
Withdrawal
Disconnect the ground wire from the battery.
Drain the engine coolant into a container.
Completely release clamps -1-, -2- and -4- and push them back.
Disconnect water hoses and pull out thermostat -3-.
Examination
Using a steel ruler or caliper, measure the position of the thermostat -1- in the housing relative to the edge of the lower fitting -2- and record the result as a measurement «A».
Warm up the thermostat in a water bath. Control the temperature with an appropriate thermometer.
At a temperature of approximately 80°-88°C, the bimetallic spring -3- of the thermostat begins to expand. Measure the position of the thermostat after exceeding the opening temperature, that is, the size «b». Size «b» must be larger «A», otherwise replace the thermostat. The opening temperature is engraved on the thermostat.
The thermostat reaches its maximum opening at approximately 95°C. When the full opening temperature is reached, measure the thermostat position. The size must be larger than the size «b» by 8±1 mm, i.e «b» — «A» = 8±1 mm.
Installation
Insert thermostat.
Fill with coolant (see section «Coolant replacement»).
Connect ground wire to battery.
Warm up the engine until the fan is turned on by the viscous coupling. Check if the lower part of the radiator is warm and if the thermostat housing is tight.
Six-cylinder engine
Withdrawal
Disconnect the ground wire from the battery.
Drain some coolant from the engine into a container.
Unscrew the cover of the thermostat housing (arrows).
Pull out the thermostat.
Examination
Warm up the thermostat in a water bath. The thermostat must not touch the walls of the vessel. Control the temperature with an appropriate thermometer.
At a temperature of about 80°C, the bimetallic spring of the thermostat begins to expand. The thermostat reaches its maximum opening at approximately 95°C.
Check the opening and closing of the thermostat and the compliance of the opening temperature with the value engraved on the thermostat housing. In case of deviations, replace the thermostat.
Installation
Clean the contact surfaces on the housing and on the cover.
Insert the thermostat with the new gasket clip outward.
Put on the cap and tighten evenly to a torque of 9 Nm.
Attention: Do not overtighten the screws.
Fill the engine with coolant and bleed air from the cooling system.
Connect ground wire to battery.
Warm up the engine until the fan is turned on by the viscous coupling. Check if the lower part of the radiator is warm and if the thermostat housing is tight.