Audi A4

Since 1994 of release

Repair and car operation



Audi А4
+ Running gear
+ Regular servicing
- Engines
   Capacity steps
   Engine signs
   Technology of the engine, maintenance service and repair
   Greasing system
   Exhaust ventilation картера
   The visual control of the engine
   Engine service life
   Nominal and maximum frequency of turns
   Restriction of number of turns
   Measurement of pressure of compression
   The help at malfunctions
   Hydropushers
   Works on a gear belt
   The help at malfunction
   Installation and dismantle of a head of the block of cylinders
   Installation and engine dismantle
+ Turbo-supercharging
+ Exhaust system
+ Cooling system
+ Fuel tank and the fuel pump
+ The air filter and channels всасывания
+ Injection system
+ Coupling
+ Transmission and the main transfer
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tyres
+ The electrotechnical equipment
+ Ignition system
+ Illumination
+ The alarm equipment
+ Tools and devices
+ Heating and ventilation
+ Body details
+ Salon
Search of malfunctions
Technical characteristics



Hydropushers

For what hydropushers serve?

At the expense of engine heating separate details клапанных mechanisms extend and extended. Therefore, that valves kept tightness, despite the a little extended cores, between a cam-shaft and тарелочными pushers should be small люфт or a backlash. This люфт – so-called клапанный the backlash – in old models of cars should to be regulated through certain time intervals. In Audi A4 at each actuating of the valve it occurs automatically at the expense of so-called hydraulic alignment клапанного a backlash which is carried out тарелочными by pushers. From here and the name "hydropushers".

Actuating of valves by means of hydropushers: oil under a high pressure is represented by red colour. Pink colour designates the quantity of the oil which have been not used for actuating of valves. By figures are designated:

1 – a cam-shaft cam;
2 – space of an oil collector;
3 – the returnable valve;
4 – oil giving;
5 – the high pressure chamber;

6 – a valve core;
7 – a press spring;
8 – the cylinder;
9 – the piston;
10 – a hydropusher.

Noise in valves

Knock in valves in the field of a cylinder head can specify in one or several defective hydropushers.

But noise in the valve can arise and at serviceable hydropushers, if:

  • Shortly before engine start oil giving on hydropushers has not been provided yet;
  • The car before it moved with full loading at high external temperature;

  • By the car long did not go. Noise should disappear at achievement by the engine of working temperature;
  • At extremely low level of oil the oil pump sometimes sucks in air.

Definition of a defective hydropusher

 PERFORMANCE ORDER

  1. Start the engine, and let it works, yet will not reach working temperature.
  2. Lift turns on 2 mines approximately to
    2500 rpm.
  3. If noise in valves does not disappear, switch off the engine and dismantle a head of the block of cylinders.
  4. Turn the cylinder № 1 in ВМТ the ignition moment.
  5. All тарелочные cylinder pushers № 1 wring out downwards wooden клинышком. If at the pressed hydropusher it is possible between it and a cam-shaft to insert a template in the thickness
    0,20 mm, replace a pusher.
  6. Repeat the same process on other cylinders. For this purpose each cylinder put in ВМТ. This position when at the checked cylinder all cams of a cam-shaft are equally turned upwards.

 Council: For replacement defective тарелочного a hydropusher it is necessary to dismantle a cam-shaft. After installation new тарелочного a pusher during 30 mines it is impossible to start the engine! The tarelochnyj pusher should "sit down". Otherwise valves will strike on the piston.


For check of hydraulic pushers it is necessary to press a plastic or wooden wedge (1) the unloaded hydraulic pusher (2). Metal tools with which it is possible to scratch easily a pusher surface, it is impossible to apply.