Audi 80/Avant (B4)

Since 1991-1995 of release

Repair and car operation

Audi 80/Avant
+ The description
+ Engines
+ System of release of the fulfilled gases
- Cooling system
   Check of level of a cooling liquid
   Frost resistance check
   Check of system of cooling on tightness
   Radiator
   Carving cover of a broad tank
   The thermostat
   The list of malfunctions
   The water pump
   Klinovoj belt of the water pump
   The fan of system of cooling
   Malfunctions of the fan of system of cooling
   The list of malfunctions
+ Fuel tank and the fuel pump
+ The air filter and воздухозаборные channels
+ Injection system
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
+ Brake system
+ Antiblocking system of brakes
+ Wheels and tyres
+ Kuzovnaja electrosystem
+ Ignition system
+ Illumination
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ Body elements
+ Search of malfunctions
+ Specifications

The thermostat

If to speak упрощенно the thermostat defines, the cooling liquid will be or not to circulate. That is, it defines, whether it is necessary a cooling liquid to pass on a small or big contour (see about it also in the beginning of this chapter). Naturally, the thermostat operates a stream of a cooling liquid depending on its temperature. It occurs by means of the sleeve filled with special wax and the plate of the valve strengthened on it.

On an illustration the water pump and the thermostat case are shown in a cut that you could glance inside. It is clearly visible лопастное a wheel (1) water pumps. Nearby the thermostat (2) is located.

After removal of a cover of the case (3) on a left-hand side of the engine the 5-cylinder engine has an access to the thermostat (2). The position (1) shows the water pump.

At heating of a cooling liquid wax thaws, extends and opens a valve plate. Until the temperature of a cooling liquid rises, the thermostat opens access to cold water from a radiator more and more. If the working temperature, on the contrary, falls, the spring in the thermostat again presses a valve plate in position "is closed" (zu), closing thereby access to cold water before working temperature.