E39 series BMW 5

since 1996-2001 of release

Repair and car operation

+ Introduction
+ Maintenance instruction
+ Current leaving and service
+ Engine
+ Systems of cooling, heating
- Power supply system and release
   + Power supply system
   + System of injection of the petrol engine
   + Power supply system of the diesel engine
   - System of production of the fulfilled gases
      Operation of the catalytic converter
      Security measures for cars with the catalytic converter
      Removal and installation of system of release
      Replacement of the main exhaust silencer
      Removal and installation of the sensor of oxygen
      Check of tightness of system of release
+ engine Electric equipment
+ Manual transmission
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ electric equipment Schemes
+ System of onboard diagnostics

Operation of the catalytic converter

All engines are equipped with the catalytic converter for purification of the fulfilled gases.

The catalytic converter has the central ceramic part of a cellular design (3) covered with a layer of the carrier. On a layer of the carrier there are the salts of precious metals operating as converters. The catalytic converter is fixed in the case (1) by means of the insulating basic layer (2) compensating at the same time thermal expansions of the catalytic converter.

Petrol engines

The Elektronnoupravlyaemy system of injection in a combination to the sensor of oxygen allows to dose out precisely amount of injected fuel that in turn reduces harmful emissions in the atmosphere. The sensor of oxygen is in a reception pipe in front of the catalytic converter and is washed by a stream of the fulfilled gases. The sensor of oxygen represents the electronic sensor measuring the content of oxygen in final gases and representing result of measurement a type of fluctuations of tension. Information from the sensor of oxygen is transferred to the control unit of system of injection. The received value allows to regulate structure of an air-petrol mix. On the one hand it is necessary in view of continuous change of service conditions (the idling, full gas), on the other hand, since optimum reburning of fuel in the catalytic converter occurs only in this case if final gases contain gasoline enough.

That in the catalytic converter at temperature 300 - 800°С there was a fuel reburning, in a fuel mix it is necessary to have the bigger content of fuel, than for pure burning.

The applied catalytic converter represents the so-called three-functional catalytic converter. It means that thanks to existence of process of regulation oxidation of an oxide of carbon (WITH) and hydrocarbon (NANOSECOND), and also reduction of concentration of oxides of nitrogen (NOx) is carried out. Address to an accompanying illustration.

Diesel engines

Cars with diesel engines are also equipped with the catalytic converter. However here adjustment of structure of a mix is impossible. The catalytic converter reduces issue of an oxide of carbon harmful to environment and hydrocarbon to value considerably smaller, than at the petrol engine. Besides, the catalytic converter reduces a characteristic smell for the diesel engine of exhaust gases. Higher concentration of oxides of nitrogen at the diesel engine decreases by means of system of a retsirkulyatsiya of the fulfilled gases.