13.2. Thermostat


Fig. 7-1. The water pump and the thermostat of cars with petrol engines of 2,8 l:
1 – thermostat; 2 – sealing ring; 3 – thermostat case; 4 – bolt, 10 N · m; 5 – laying; 6 – water pump; 7 – bolt, 10 N · m

The thermostat is located in the case (fig. 7-1) established on the block of cylinders of the engine.
Merge cooling liquid.
Take off poliklinovy a belt and the mechanism of its tension.
Remove the left and right casings of a gear belt.
Using a marker, chalk or paint, note the direction of rotation of a gear belt.
Weaken a tension of a gear belt. Slightly turn a bent shaft in both parties for weakening of a tension of a gear belt and take off a gear belt from a tension roller and the right pulley of the camshaft.
For protection of a gear belt against cooling liquid close it polyethylene.

Fig. 7-2. Arrangement of bolts of fastening of the case of the thermostat

Unscrew two bolts and remove the thermostat case from a forward part of a head of the block of cylinders (fig. 7-2).
Take a sealing ring and the thermostat from a head of the block of cylinders. Check operability of the thermostat.


Fig. 7-3. The correct arrangement of the thermostat on petrol engines of 2,8 l

Install the thermostat in a head of the block of cylinders so that the valve for removal of air settled down from above (fig. 7-3).
Install the thermostat case with a new sealing ring and fix by bolts, having tightened their moment 10 N · m.
Establish a gear belt on a camshaft pulley.
Establish poliklinovy a belt.
Fill in cooling liquid in the cooling system.
Launch the engine and check tightness of the cooling system.

Check of operability of the thermostat

Fig. 7-4. Working provisions of the valve of the thermostat: and - the valve is closed; b - the valve is open

Measure length and the closed thermostat (fig. 7-4).
Approximately it is possible to check operability of the thermostat so: to suspend it on a thread in the glass vessel filled with water and to heat water to boiling. When boiling water the valve of the thermostat has to open. Otherwise replace it.
Temperature of opening of the valve of the thermostat is put on its case.
When heating the thermostat to water boiling temperature length of b of the open thermostat with the open valve has to be more than length and with the closed valve on 7 mm (see fig. 7-4).
The thermostat which valve is not closed when cooling water is also subject to replacement.