Audi A4

since 1994 of release

Repair and car operation

A4 Audi
+ Running gear
+ Regular servicing
- Engines
   Capacity steps
   Engine signs
   Technology of the engine, maintenance and repair
   Greasing system
   Exhaust ventilation of a case
   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
   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 fuel pump
+ Air filter and absorption channels
+ injection System
+ Coupling
+ Transmission and main transfer
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tires
+ Electrotechnical equipment
+ ignition System
+ Lighting
+ Alarm equipment
+ Tools and devices
+ Heating and ventilation
+ body Details
+ Salon
Search of malfunctions
Technical characteristics


For what hydropushers serve?

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

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

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

6–valve core;
7–press spring;

Noise in valves

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

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

    shortly before start of the engine supply of oil on hydropushers was not 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


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

 Council: For replacement of a defective tarelochny hydropusher it is necessary to dismantle a cam-shaft. After installation of a new tarelochny pusher during 30 mines it is impossible to start the engine! The Tarelochny 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.