Citroën Xantia

since 1993 release

Repair and operation of the car

Turbocompressor - general information and precautionary measures

General information

Scheme of functioning of a turbocompressor

Some models are equipped with the system of a turbo-supercharging increasing efficiency of return of the engine due to rise in pressure in the inlet pipeline is higher than atmospheric. Now air instead of just being soaked up in cylinders, is forced in the engine under a pressure. TNVD at the same time provides giving of additional amount of fuel, supporting by that the required composition of gas mixture.

Functioning of a turbocompressor is provided due to kinetic energy of the fulfilled gases (see the illustration Scheme of Functioning of a Turbocompressor). The stream of final gases is banished through a special form a turbine casing, forcing a wheel of the last to rotate at the same time. The wheel of the turbine is fixed on a shaft since which other end the second wheel which is also equipped with shovels and called by a compressor wheel is established. The wheel of the compressor rotates in own casing, compressing at the same time the external air given to the inlet pipeline.

On the road from a turbocompressor to the inlet pipeline the stream of air is banished through the built-in cooler of system of a turbo-supercharging (Intercooler). This device represents the heat exchanger functioning by the principle air-air, is established outside on the engine and provides selection of heat from the air given to combustion chambers and transfer to its external air banished through podkapotny space. A problem of the built-in cooler is compensation of the heating of air mass happening owing to its compression in a turbocompressor. As density of gases is inversely proportional to their temperature, it allows to increase efficiency of action of a turbocompressor and, respectively, return of the engine.

Pressurization pressure size (pressure in the inlet pipeline) is limited by means of the special waste gate providing removal of the fulfilled gases from a turbine wheel at the command of pressure of the actuation mechanism, sensitive to change. At the same time the special sensor switch makes inclusion of the control lamp on an instrument guard of the car informing the driver on excess of extreme value of pressure of pressurization.

Greasing of a shaft of the turbine is carried out due to giving on it being under pressure of engine oil. Oil under a pressure on the special giving tube arrives from the main oil gallery of the engine. Return of oil to the pallet of a case of the engine is carried out on the second (by-pass) tube. The system provides practically posting of a shaft on an oil pillow, allowing it is essential to increase the term of operation of a turbocompressor.

Precautionary measures

The turbocompressor works in the conditions of very high speeds of rotation and considerable temperatures in view of what at its service it is necessary to observe some special precautionary measures.

Do not allow functioning of a turbocompressor with open internal details at all, or at the disconnected hoses. Hit in the device of foreign objects easily leads to failure of turbine shovels and, besides, constitutes personal danger to the contractor.

Do not raise engine turns right after implementation of its start (especially cold). Let's oil protsirkulirovat a little on the engine.

Before suppressing the engine, wait for final dumping of its turns to single. Otherwise, the turbine will continue to rotate by inertia without lubricant for some time.

After a high-speed trip before muffling, let's the engine work a little on single turns.

Try to observe intervals of routine maintenance of the car strictly. Remember that the careless relation to regular change of oil and an oil filter leads to formation of coal deposits on a shaft of the turbine and essential reduction of service life of a turbocompressor.