Removal and installation
It is difficult to remove the thermostat on the road, since it is necessary to drain the coolant completely. In addition, when the engine is hot, this process takes a very long time, since it is necessary to wait until the coolant cools down. When replacing the thermostat, you also need to install a new sealing ring, in which the thermostat is located in the radiator hose (engine type "C") or in the housing (engine type "F"), and a new thermostat housing gasket.
1. Unscrew the expansion tank cap to bring the pressure in the cooling system to atmospheric pressure.
Attention! Attention! Unscrew with a thick cloth so as not to burn yourself!
2. Disconnect the lower radiator hose, drain 2-3 liters of coolant into a clean container.
3. Disconnect the upper radiator hose from the coolant pump (type "C" engine) or from the thermostat housing (type "F" engine) and from the cylinder head.
4. Type "C" engine: Cut off the factory clamps with a knife.
5. Move the stuck thermostat by squeezing the radiator hose. Remember how it was installed (the direction of fluid movement is important!).
6. Before installation, clean the place where the thermostat is attached in the hose from scale. Then install the thermostat and fix its position with a threaded clamp.
7. Engine type "F": Unscrew the 3 thermostat housing bolts and carefully remove the housing.
8. If the body does not give in, help yourself by hitting with your hand.
9. Release the thermostat safety clamp and remove the thermostat and sealing ring from the housing.
10. Before installation, clean the sealing surfaces from any remaining sealant. Then apply a layer of sealant to them (for example, Loctite 518) thickness no more than 1 mm.
Checking the Thermostat
Using a thermometer, you can check for yourself whether the thermostat actually turns on at the required temperature.
1. Disconnect the thermostat.
2. Place the thermostat in a container of water and heat the water.
3. Make sure that the valve lifts from its place at the required temperature.
In the C-type engine, the thermostat is located in the upper radiator hose and is clamped there between two hose clamps (shown by arrow).
On "F" type engines, the thermostat is bolted to the front of the engine in the housing. Coolant pumped by the pump passes through the engine and flows back to the radiator through the top hose after the thermostat.
| engine | 1.4 liter (C3J) | 1.7 liter (F3N) | 1.8 liter (F3P) | 16-valve (FTP) | Diesel (F8Q) |
| Thermostat opening temperature open fully at * | 86°C 98°C | 89°C 98°C | 89°C 101°C | 89°C 101°C | 82 єC 94 єC |
* the used thermostat may have a fluctuation of ±3°C