Audi A3

Since 1997 of release

Repair and car operation

Audi A3
+ The maintenance instruction
+ Current leaving and service
+ The engine
+ Systems of cooling, heating
- The power supply system and release of the fulfilled gases
   + The power supply system
   + System of injection of fuel
   + System of injection of the diesel engine
   - System of release of the fulfilled gases
      Work каталитического the converter
      Security measures for an exception of damages каталитического the converter
      Removal and installation of system of release
      Checking of system of release
      Replacement of the central/additional muffler
      Check of system of release on tightness
      Replacement of the gauge of oxygen
+ Engine electric equipment
+ Manual box of a gear change
+ Automatic transmission and models with a full drive
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Electroschemes

Security measures for an exception of damages каталитического the converter


The system scheme турбокомпрессора

1 - an adsorber with the activated coal
2 - the ventilating pipeline from a fuel tank
3 - the return valve for an adsorber with the activated coal
4 - турбокомпрессор with a drive from exhaust gases
5 - a regulator of pressure of fuel
6 - the inlet pipeline (a fuel highway)
7 - ventilation картера the engine
8 - the return valve of an adsorber with the activated coal
9 - connection on the case throttle заслонки
10 - интеркулер (a cooler of forced air)
11 - a receiver интеркулера
12 - the valve отсечки at movement накатом
13 - the electromagnetic valve for restriction of pressure of pressurisation
14 - the valve of restriction of pressure of system of ventilation картера
15 - электрически the operated valve of an adsorber

For an exception of damages of the gauge of oxygen and каталитического the converter it is necessary to fulfil following requirements:

Petrol engines

– Necessarily apply only Unleaded gasoline.
– Start of the heated-up petrol engine by pushing or towage is authorised to be spent only in one attempt and on distance no more the starting cable is better to apply than 50 m. to this purpose. Not burnt down fuel at ignition can lead to an overheat каталитического the converter and to its destruction.

Start of cars with АТ is for technical reasons impossible.

– At difficulty with engine start it is not necessary to include a starter too long. Constant injection of fuel is thus made. It is necessary to reveal and eliminate a cause of defect.
– If there are malfunctions with ignition system, at definition of their character it is necessary to exclude fuel injection at starter inclusion. For this purpose disconnect the relay of the fuel pump.
– Never spend fuel in a petrol tank completely.
– At occurrence of faults in ignition do not raise number of turns of the engine and immediately eliminate malfunction.
– Apply only the recommended spark plugs.
– Do not spend check of a spark with disconnected штекерным spark plug connection.
– Carrying out of the test of work of the cylinder by switching-off of a wire of ignition from its candle is not supposed. Thus not burnt down fuel gets in каталитический the converter.
– Do not stop the car over dry foliage or a grass. The system of release of the fulfilled gases in area каталитического the converter very hot also radiates heat even after an engine stop.
– Do not put on elements of system of release of means for protection of the bottom of the car.
– It is not supposed to change a design of heat-shielding screens.
– At filling of the engine with oil especially pay attention to to exceeding at all the level designated on the index as Max. Surplus of oil owing to incomplete combustion arrives in каталитический the converter and can damage its covering from the alloyed metal or completely to destroy каталитический the converter.


Petrol engines of 1.8 l of 150 h.p. are equipped турбокомпрессором.

turbocharger has two turbines established on one shaft and placed in two separate cases: приводная the turbine working from fulfilled gases, and the delivery turbine compressing air, arriving in the engine. Thus angular speed of rotation of a shaft of the turbine reaches 120 000 rpm. Greasing турбокомпрессора is carried out from system of greasing of the engine. In addition турбокомпрессор it is cooled by a liquid of system of cooling of the engine.

The increase in capacity of the engine at the expense of a turbo-supercharging reaches 100 %. Growth of capacity among the other depends on pressure of submitted air which at engines of cars makes 0.4 – 0.8 bar (pressure of air in tyres makes 1.8 bar). Pressure of air is supervised by the gauge. If pressure of air exceeds the established value, the valve of adjustment of pressure opens, reducing it.

Along with increase of capacity owing to application турбокомпрессора the twisting moment increases also that, first of all, affects improvement of elasticity of the engine. A condition of reliable pressurisation is rotation турбокомпрессора with demanded number of turns. Therefore at the engine it is established concerning small турбокомпрессор which starts to work already at small numbers of turns of the engine, and raises its twisting moment.

Between турбокомпрессором and an inlet path of the engine is интеркулер (a cooler of submitted air). Air cooling promotes increase of capacity of the engine as cold air thanks to higher density has higher maintenance of oxygen.

In the diesel engine regulated турбокомпрессор (турбокомпрессор with adjustable geometry) provides increase in capacity of the engine. Smooth adjustment of shovels is carried out by a control system of the engine through the electromagnetic valve and a vacuum box. Thanks to it at any number of turns optimum pressure of pressurisation and by that increase of capacity of the engine is reached, in particular, at low turns of the engine.

turbocharger represents the precision mechanism. Therefore, as a rule, in case of malfunction турбокомпрессор it is necessary to replace.

Malfunctions турбокомпрессора

If турбокомпрессор works incorrectly, it can be defined on decrease in capacity or impossibility of achievement of the maximum speed in the assumption that the system of injection of fuel works normally. It can be caused leak in system or malfunction турбокомпрессора. The following sequence of checks is recommended:

Leaks in system

Check up an air hose between турбокомпрессором and the inlet pipeline through интеркулер on presence of breaks, the cracks, the weakened connections etc. And at their detection eliminate them. Check up, whether there is no thinness between a head of cylinders and the inlet pipeline. It can occur because of defective linings or, in certain cases, because of pipeline displacement.
Thinnesses can be in connecting flanges between a final collector and a head of cylinders or between a final collector and турбокомпрессором.

Faulty турбокомпрессор

Check up pressure of pressurisation in a workshop. It can be either too high or too low. If pressure too high malfunction of the electromagnetic valve of restriction of pressure of pressurisation or a receiver of the regulating valve of pressure of pressurisation can be the reason of it. Interrogation of memory of the device of diagnostics in a workshop will help to establish, where malfunction.

If pressure too low it is possible to suspect a receiver of the device of restriction of pressure of pressurisation. Otherwise it should be faulty турбокомпрессор.


As it is known, the engine after a long trip with high speed cannot be switched off at once, it is necessary to allow for it to work a little idling. The reason of it in the following: if at once to muffle “перегретый” the engine the shaft bearing турбокомпрессора will heat up so that oil for bearing greasing can burn out. At such reference and restart турбокомпрессор will soon fail.

turbocharger it is sensitive enough to a dirt or alien subjects, therefore at removal and installation it is necessary to observe cleanliness.

1. Disconnect a wire of "weight" from the storage battery (do not forget about the radio receiver coding).
2. Remove an air hose from турбокомпрессора.
3. Press the hose of a cooling liquid going to турбокомпрессору by means of a clamp or merge cooling liquid.
4. Lift and establish a forward part of the car on supports.
5. Disconnect fastening of an exhaust system from РКПП. Disconnect the catalyst from турбокомпрессора (4 nuts). Disconnect bringing and taking away oil tubes from турбокомпрессора. Watch, that has flowed out less oils. From the bottom party turn away fastening bolts турбокомпрессора from a final collector. To these bolts it is hard to reach, therefore it is necessary to take advantage of a suitable key (накидной a key on 12 mm). Thus keep турбокомпрессор and when all bolts will be removed, extend it upwards. Installation is carried out in an order, the return to removal. Always use new nuts and bolts. Before connection of a tube of a supply of oil fill in a few oils in турбокомпрессор (preliminary greasing). At first let's to the engine work on high turns.

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