13.2. The thermostat
Fig. 7–1. The water pump and the thermostat of cars with petrol engines of 2,8 l:
1 – the thermostat; 2 – a sealing ring; 3 – the thermostat case; 4 – a bolt, 10 Нм; 5 – a lining; 6 – the water pump; 7 – a bolt, 10 Нм
The thermostat is located in the case (fig. 7–1), established on the block of cylinders of the engine.
Merge cooling liquid.
Remove полиwedge a belt and the mechanism of its tension.
Remove the left and right casings of a gear belt.
Using a marker, a chalk or a paint, note a direction of rotation of a gear belt.
Loosen the a tension of a gear belt. Slightly turn a cranked shaft in both parties for easing of a tension of a gear belt and remove a gear belt from a tension roller and the right pulley of a camshaft.
For protection of a gear belt against a cooling liquid close its polyethylene.
Fig. 7–2. An arrangement of bolts of fastening of the case of the thermostat
Unscrew two bolts and remove the case of the thermostat 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 up working capacity of the thermostat.
Fig. 7–3. A correct arrangement of the thermostat on petrol engines of 2,8 l
Establish the thermostat in a head of the block of cylinders so that the valve for air removal settled down from above (fig. 7–3).
Establish the case of the thermostat with a new sealing ring and fix bolts, having tightened their moment 10 Нм.
Establish a gear belt on a camshaft pulley.
Establish полиwedge a belt.
Fill in cooling liquid in cooling system.
Start up the engine and check up tightness of system of cooling.
Check of working capacity of the thermostat
Fig. 7–4. Working positions of the valve of the thermostat: and - the valve is closed; b - the valve is opened
Measure length and the closed thermostat (fig. 7–4).
Approximately to check up working capacity of the thermostat it is possible so: to suspend it on a thread in the glass vessel filled with water, and to heat up water to boiling. At boiling of water the thermostat valve should open. Otherwise replace it.
The temperature of opening of the valve of the thermostat is put on its case.
At heating of the thermostat to temperature of boiling of water the length b the open thermostat with the open valve should be more lengths and with the closed valve on 7 mm (fig. 7–4 see).
The thermostat, which valve is not closed at water cooling, also is subject to replacement.