Thermostat is a device for maintaining a static (constant) temperature, as its name implies. There are thermostats of different designs in many devices and mechanisms, from water heaters to refrigerators. There is also a thermostat in a car's internal combustion engine (liquid-cooled, of course). In a car, the thermostat regulates the temperature of the coolant (antifreeze): it accelerates the warm-up of a cold engine and provides heat removal from the hot one. Therefore, the engine works more efficiently and more comfortably for the driver, especially in winter - without a thermostat, the stove would usually blew cold air.

1. 6 Coupe (F13)
2. 5 Touring (F11)
3. 5 (F10)
4. 6 Convertible (F12)
5. X3 (F25)
6. X3 SAV (F25)
7. X5 (F15, F85)
8. X5 SAV (F15, F85)
9. 4 Coupe (F32, F82)
10. 3 (F30, F80)
11. 3 Touring (F31)
12. 7 (F01, F02, F03, F04)
13. 7 Saloon (F01, F02, F03, F04)
14. X5 (E70)
15. X5 SAV (E70)
16. X6 (E71, E72)
17. X6 SAC (E71, E72)
18. 5 Gran Turismo (F07)
19. 6 Gran Coupe (F06)
20. 3 Gran Turismo (F34)
21. See more in applications

The principle of the thermostat work

The classic METZGER brand Thermostat, coolant is a movable valve that moves due to a change in the external environment - heating or cooling of antifreeze. The thermostat is made of a thermoelement filled with a substance resembling wax in structure - ceresin, with the addition of copper powder, graphite or aluminum for better thermal conductivity. At a certain temperature of the antifreeze, ceresin expands, opening the thermostat valve. When the motor cools down, ceresin contracts and the thermostat closes again.