An engine cooling system device designed to switch fluid circulation circuits - a thermostat. This element of the cooling system operates cyclically in closed and open mode.

1. GOLF VI (5K1)
2. R8 (422, 423)
3. SCIROCCO (137, 138)
4. R8 Spyder (427, 429)
5. A8 (4E2, 4E8)
6. A8 Saloon (4E2, 4E8)
7. A8 / S8 (4E2, 4E8)
8. A8L (4E2, 4E8)
9. GOLF V (1K1)
10. RABBIT V (1K1)
11. EOS (1F7, 1F8)
12. JETTA III (1K2)
13. JETTA I Saloon (1K2)
14. JETTA V (1K2)
15. BORA V (1K2)
16. VENTO III (1K2)
17. PASSAT (3C2)
18. PASSAT Saloon (3C2)
19. PASSAT / Magotan (3C2)
20. PASSAT Variant (3C5)
21. See more in applications

At a low temperature of the coolant, the thermostat is closed, which contributes to its movement in a small circle and rapid heating to operating temperature. Upon reaching the nominal value, the thermostat opens and directs the coolant in a large circle through the radiator, where it is cooled. Thus, the constant opening and closing of the thermostat valve helps to maintain a constant temperature of the antifreeze in the system.

The construction of an FEBI BILSTEIN brand Thermostat, oil cooling

The main elements of the thermostat:

1. frame;
2. stock;
3. thermoelement (usually artificial wax);
4. valve with piston and spring;
5. seals;
6. guiding device.

The thermostat can be framed or non-framed (mounted in the engine block). It has marking and embossed technical parameters (full opening temperature).