Audi A4, S4

Since 2000 of release

Repair and car operation



Audi A4, S4
+ Introduction
+ Controls and receptions of safe operation
+ Current leaving and service
+ The engine
- Systems of cooling, heating and the air conditioner
   - Cooling system
      The general information
      Antifreeze - a protection frame from freezing
      Replacement of a cooling liquid
      Removal and thermostat installation
      Thermostat check
      Replacement of hoses of system of cooling
      Removal and radiator installation
      Removal and installation of the fan of a radiator
      Removal and installation of the pump of a cooling liquid
   + Systems of ventilation, heating and air conditioning
+ Power supply systems, release and decrease in toxicity of the fulfilled gases
+ Systems of an electric equipment of the engine
+ Manual box of a gear change
+ Automatic transmission
+ Coupling, power shafts and differential
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment



Cooling system

The general information

The scheme of connections of hoses of system of cooling

1 — a heater Radiator
2 — Pipeline OZH bottom
3 — the Broad tank
4 — Masloohladitel
5 — the Inlet pipeline
6 — the Bottom hose of a radiator
7 — the Top hose of a radiator

8 — the Radiator
9 — Pipeline OZH top
10 — the Water pump with the thermostat
11 — Turbokompressor
12 — the Block and a head of cylinders
13 — the Target union

On some models the system of regulation of temperature of the cooling liquid, working on put in the block of management to the characteristic is applied. In comparison with usual system of cooling such system raises thermodynamic efficiency of the engine and thus optimises the twisting moment characteristic.

The system of the cooling working under the set characteristic, consists of the distributor of a cooling liquid with the thermostat, an electric heating element, and also springs, for mechanical lock-out of channels of a cooling liquid.

By means of the warmed up thermostat the temperature of a cooling liquid is regulated by the engine management block under the characteristic put in it. The temperature, optimum from the point of view of given capacity of the engine is thus supported.

For example, at full loading of the engine the extending element heats up and thus the thermostat opens more. The temperature of a cooling liquid that leads to more intensive cooling of chambers of combustion Thereby decreases. Colder chambers of combustion lead to earlier ignition and by that to increase in a twisting moment of the engine.

The cooling liquid goes through a radiator constantly working pump. The liquid passes through a radiator from top to down and is cooled by air passing through it. The fan of a cooling liquid with the electric drive is applied.

Heater and ventilation

The heater consists of fans and the heat exchangers located in blocks of forward and back parts of salon. The hot cooling liquid passes through heat exchangers. At moving of the handle of management by modes of the heater, located on the control panel, valves open, and hot air starts to arrive in car salon. If to include the heater fan, air will move in salon compulsorily.

Intaking air before getting to salon, passes through the filter (address to the Head Current leaving and service). The basic share of particles of a dust will settle in the filter. It is necessary to observe periodicity of replacement of the filter. The filter littered by a dust will limit air giving in salon that will lead to a stagnation of air in salon.

Distribution of streams of air of system of ventilation is carried out with the help заслонок. The air circulation mode is provided. Заслонки cope servo-drivers.