Audi A4

since 1994 release

Manual of the car

Audi A4
+ Running gear
+ Regular servicing
+ Engines
+ Turbo-supercharging
+ System of an exhaust
- Cooling system
   So there is a cooling
   Check of level of cooling liquid
   Antifreeze check
   Check of the cooling system on tightness
   Locking cover of the cooling system
   The help at malfunctions
   Water pump
   Maple belt of the water pump
   Various models of fans
   Viscous fan
   The radiator fan with the electric drive
   Violations in operation of the fan of a radiator
   The help at malfunctions
+ Fuel tank and fuel pump
+ Air filter and channels of absorption
+ System of injection
+ Coupling
+ Transmission and main transfer
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tires
+ Electrotechnical equipment
+ System of ignition
+ Lighting
+ Alarm equipment
+ Tools and devices
+ Heating and ventilation
+ Body details
+ Salon
Search of malfunctions
Technical characteristics


Viscous fan

Here you see the viscous fan (the radiator fan) of the six-cylinder engine. Its knots:

1 – fan blade;
2 – an axis of viscous coupling – at the six-cylinder engine with a big fixing bolt with a six-sided head;

3 – viscous coupling.

For economy of power this fan is supplied with so-called viscous coupling. It turns on the fan at the ambient temperature of 82 °C. It is carried out by means of a bimetallic tape which, being temperature and dependent, via the valve lets in viscous silicone oil working space of viscous coupling. Oil creates power short circuit between a belt pulley and the fan – the fan gives cool air. At a temperature below 60 °C silicone oil comes back from working space to a collector – the fan rotates with a smaller speed, without spending power.

Dismantle of the viscous fan

Dismantle of the viscous fan of the six-cylinder engine: to weaken a fixing bolt of the fan, it is necessary to block a belt pulley: to insert the screw-driver into an opening (2) and to rest against an arm (1).

The same process which is described in the dismantled engine at the left is shown in the car here. The screw-driver is inserted into an opening (2) and rests against an arm (1). It is possible to unscrew a bolt (3).

Dismantle of the viscous fan at the four-cylinder engine: the belt pulley (1) is blocked by a bolt of M5 X 60 (2), the fixing bolt can be unscrewed a key with an internal hexagon of 8 mm (3).


  1. Four-cylinder engine: unscrew a key behind in the fan bearing a fixing bolt with an internal hexagon
    in 8 mm. Block a belt pulley, having inserted a bolt of M5 X 60.
  2. Remove the viscous fan.
  3. Unscrew its coupling from the fan.
  4. At installation tighten a bolt on 70 Nanometers.
  5. The fan inhaling moment at coupling: 10 Nanometers.
  6. Six-cylinder engine: weaken a fixing bolt of the fan (it at the same time is a fan axis) Rozhkov SW 32 key.

     Attention: left carving! Block at the same time a belt pulley the screw-driver. The screw-driver rests against the arm provided for this purpose.

  7. Remove the viscous fan.
  8. Unscrew viscous coupling on the fan.
  9. At installation tighten a bolt on 70 Nanometers.
  10. The fan inhaling moment on coupling: 10 Nanometers.