Audi 80/Avant (B4)

since 1991-1995 release

Repair and operation of the car

Audi 80/Avant
+ Technical specification
+ Engines
+ System of production of the fulfilled gases
- Cooling system
   Check of level of cooling liquid
   Frost resistance check
   Check of the cooling system on tightness
   Carving cover of a broad tank
   List of malfunctions
   Water pump
   Maple belt of the water pump
   Cooling system fan
   Malfunctions of the fan of the cooling system
   List of malfunctions
+ Fuel tank and fuel pump
+ Air filter and airintaking channels
+ System of injection
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
+ Brake system
+ Anti-blocking system of brakes
+ Wheels and tires
+ Body electrical system
+ System of ignition
+ Lighting
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ body Elements
+ Search of malfunctions
+ Specifications

Cooling system

The cooling system in Audi 80 carries out two functions: cools the engine and warms salon. Usually it is very reliable but if after all there were malfunctions, this head will help you to deal with these problems.

So there is a cooling

At the working engine the water pump constantly pumps over cooling liquid on numerous cooling channels of the engine and deletes heat arising in cylinders at combustion.

The drive of the water pump in the 4-cylinder engine is provided with a maple belt, in the 5-cylinder engine a gear belt, and in the 6-cylinder engine – a poliklinovy belt.

The way of passing of cooling liquid depends on its temperature of time at present:

  • If the engine did not reach working temperature yet, cooling liquid flows on the small contour passing through the engine and the heat exchanger. In addition to a small contour of cooling liquid the inlet collector is connected.
  • On reaching temperature about 87 °C the thermostat opens a big contour which includes also a radiator. If temperature of cooling liquid rises further so even in a radiator temperature makes over 92 °C, into action goes the radiator fan, helping when cooling.

The cooling system calculated on work with an excessive pressure

In the cooling system at a working temperature the elevated pressure of 1,2 - 1,5 bars that increases temperature of boiling of cooling liquid above 100 °C dominates. Thereby a certain reserve is created. The engine can reach the working temperatures exceeding 100 °C and thus in the cooling system there is no danger of boiling.

The correct pressure in system is created thanks to a carving cover of a broad tank which is supplied with the safety valve (1,2 – 1,5 bars) and the vacuum valve (0,06 – 0,1 bars). The vacuum valve lets in air if cooling liquid becomes colder and by that takes less places.