Audi A4, S4

since 2000 release

Repair and operation of the car

Audi A4, S4
+ Introduction
+ Governing bodies and methods of safe operation
+ Current leaving and service
+ Engine
- Cooling systems, heating and air conditioner
   - Cooling system
      General information
      Antifreeze - a security measure from freezing
      Replacement of cooling liquid
      Removal and installation of the thermostat
      Check of the thermostat
      Replacement of hoses of the cooling system
      Removal and installation of a radiator
      Removal and installation of the fan of a radiator
      Removal and installation of the pump of cooling liquid
   + Systems of ventilation, heating and air conditioning
+ Power supply systems, release and decrease in toxicity of the fulfilled gases
+ Systems of electric equipment of the engine
+ Manual box of gear shifting
+ Automatic transmission
+ Coupling, power shafts and differential
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment

Removal and installation of the thermostat

Diesel engine of 1.9 l

At cars with the cooling system working according to the set characteristic, the ordinary thermostat is absent.



  1. Merge cooling liquid.
  1. Disconnect the lower hose of cooling liquid from a connecting branch pipe (2). Previously open a collar and completely shift it back.
  1. Turn out bolts (1) and remove a connecting branch pipe with the thermostat (4).
  1. Turn the thermostat on 90 ° to the left and take out from a connecting branch pipe.



  1. Surely replace consolidations and sealing rings.
  2. Clear sealing surfaces.
  3. Insert the thermostat (4) with a new sealing ring (3) into a connecting branch pipe (2) and turn on 90 ° to the right.

Collars of the thermostat have to stand almost vertically.

  1. Insert a connecting branch pipe with the thermostat into the block of cylinders and fix it the moment 15nm.
  2. Fill system with cooling liquid, address to the Section Check of the Engine by means of the vacuum gage.