Audi A4, S4

since 2000 of release

Repair and car operation

Audi A4, S4
+ Introduction
+ Governing bodies and receptions of safe operation
+ Current leaving and service
+ Engine
+ Systems of cooling, heating and air conditioner
+ Power supply systems, release and decrease in toxicity of the fulfilled gases
- Systems of electric equipment of the engine
   + ignition and engine management System
   - System of preheat of the diesel engine
      General information
      Removal and installation of candles of an incandescence
      Check of candles of an incandescence
   + Diagnostics of systems of electronic control and diagnostic equipment
   + charging and start Systems
+ Manual box of gear shifting
+ Automatic transmission
+ Coupling, power shafts and differential
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment


System of preheat of the diesel engine

General information

On the cold diesel engine, at air compression in the cylinders, necessary for fuel spontaneous ignition the temperature is not reached. For this reason preheat is required.

For this purpose in each chamber of combustion the glow plug is established. The glow plug consists of the case with vpressovanny in it a heating core. The heating core in turn consists of a heating spiral and an adjusting spiral. After tension giving the heating spiral in a core heats up within several seconds to temperature + 850°С. Thus the current passing on a candle, reaches 30А. At increase in heating resistance of a spiral that limits a current to 15-25 A.Kogda a control lamp of preheat on the dashboard increases dies away, the engine can be started.

Time of preheat necessary for start of the engine, makes no more than 10 pages. Time is regulated by the relay of preheat and the control unit the engine which via the sensor of temperature of cooling liquid receives information on the current temperature of the engine. The control unit the engine on the basis of received information makes the decision on duration of inclusion of candles of an incandescence and a necessary current of heating.

On the diesel engine with direct injection preheat is required only at temperature below 0°С.