Audi 80/Avant (B4)

Since 1991-1995 of release

Repair and car operation

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

So there is a cooling

At the working engine the water pump constantly pumps over cooling liquid on numerous охладительным to 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 клиновым with a belt, in the 5-cylinder engine a gear belt, and in the 6-cylinder engine – поликлиновым a belt.

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

If the engine yet has not reached working temperature the cooling liquid flows on the small contour passing through the engine and the heat exchanger. In addition the inlet collector is connected to a small contour of a cooling liquid. On reaching temperature approximately 87С the thermostat opens the big contour which includes also a radiator. If the temperature of a cooling liquid rises further so even in a radiator the temperature makes from above 92С, business is entered by the radiator fan, helping at cooling.

The system of cooling calculated for work at superfluous pressure

In cooling system at working temperature the elevated pressure 1,2 – 1,5 bar that raises temperature of boiling of a cooling liquid considerably above 100С dominates. Thereby the certain reserve is created. The engine can reach workers of the temperatures exceeding 100С, and thus in system of cooling there is no danger of boiling.

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