Audi A4

since 1994 release

Repair and operation of the car

A4 Audi
+ Running gear
+ Regular servicing
- Engines
   Power steps
   Engine signs
   Technology of the engine, maintenance and repair
   Lubrication 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
   Hydropushers
   Works on a gear belt
   The help at malfunction
   Installation and dismantle of a head of the block of cylinders
   Installation and dismantle of the engine
+ Turbo-supercharging
+ System of an exhaust
+ Cooling system
+ Fuel tank and fuel pump
+ Air filter and channels of absorption
+ System of injection
+ Coupling
+ Transmission and main transfer
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tires
+ Electrotechnical equipment
+ System of ignition
+ Lighting
+ Alarm equipment
+ Tools and devices
+ Heating and ventilation
+ body Details
+ Salon
Search of malfunctions
Technical characteristics

Measurement of pressure of compression

For measurement it is necessary to warm up the engine. Tightness of piston rings increases when oil is hotter. Besides, it is necessary to stop supply of fuel in cylinders. Otherwise at measurement of pressure the engine will be filled in with fuel that can damage the catalytic converter. And, at last, it is necessary to switch off ignition, without the connected candles the ignition coil at start of the engine can be damaged.

At the left: measurement of pressure of compression by the inexpensive measuring device for fans.

On the right: in order that at measurement of pressure of compression fuel was not injected in cylinders, on all valves of injection (shooters) sockets are removed.

PERFORMANCE ORDER

Switch off ignition and stop fuel supply. In different models it becomes differently:
Four-cylinder the engine with a working volume of 1,6 l: disconnect the socket of a terminal exit of power of the coil of ignition.
Disconnect sockets of all four valves of injection.
The four-cylinder engine with a working volume of 1,8 l: coils of ignition are dismantled anyway (the head System of ignition), thus also sockets on coils of ignition or a terminal exit are disconnected. Disconnect sockets of all four valves of injection.
Six-cylinder engine: disconnect both sockets at the final exit of power of coils of ignition (the head System of ignition). Disconnect sockets of all six valves of injection.
For all models: unscrew all spark plugs.
Press a rubber cone of the manometer to an opening of a candle of the first cylinder (the sequence does not matter, but write down) or screw in a connecting tube in a spark plug carving.
Turn on the emergency brake, put the lever of gear shifting in neutral situation or the lever selector of an automatic transmission in situation "P".
Let your assistant a starter will turn the engine. The pedal of gas has to be wrung completely out thus (for the purpose of the best filling of the cylinder).
When pressure indicator already significantly does not rise, write down it and take measurements on the following cylinder.

Pressure indicators

Here pressure indicators according to Audi are given:

Engine	The 14-cylinder		The 16-cylinder
Alphabetic reference of the engine	ADP/ADR	AEB	ABC/AAH
Compression pressure nominal size, bar	9–14	10–13	9–14
Minimum size, bar	7,5	7,0	7,5
The maximum distinction in pressure, bar	3,0	3,0	3,0