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. PASSAT Variant (3C5)
2. PASSAT Estate (3C5)
3. TIGUAN (5N_)
4. TIGUAN/TIGUAN LIMITED SUV (5N_)
5. SHARAN (7M8, 7M9, 7M6)
6. JETTA IV (162, 163, AV3, AV2)
7. JETTA VI (162, 163, AV3, AV2)
8. JETTA / CLASICO VI (162, 163, AV3, AV2)
9. BORA IV (162, 163, AV3, AV2)
10. SCIROCCO (137, 138)
11. A3 (8P1)
12. A3 / S3 (8P1)
13. TOURAN (1T1, 1T2)
14. GOLF V (1K1)
15. RABBIT V (1K1)
16. A6 (4F2, C6)
17. A6 Saloon (4F2, C6)
18. A6 / S6 (4F2, C6)
19. ALTEA (5P1)
20. OCTAVIA II (1Z3)
21. See more in applications

The principle of the thermostat work

The classic MAHLE ORIGINAL 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.