Audi 80/Avant (B4)

since 1991-1995 of release

Repair and car operation

Audi 80/Avant
+ Technical specification
+ Engines
+ System of production of the fulfilled gases
+ cooling System
+ Fuel tank and fuel pump
- Air filter and airintaking channels
   Removal of a replaceable element of the air filter
   Purge of a replaceable element of the air filter
   Replacement of a replaceable element of the air filter
   Heating of inlet air
   Heating of an inlet collector
   Inlet collector with changeable length of a path
+ injection System
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
+ Brake system
+ Anti-blocking system of brakes
+ Wheels and tires
+ Body electrosystem
+ ignition System
+ Lighting
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ body Elements
+ Search of malfunctions
+ Specifications

Inlet collector with changeable length of a path

Fixing bolts of an inlet collector of 2,6-liter and 2,8-liter 6-cylinder engines should be tightened in the specified sequence. Only this way it is possible to prevent a distortion of an inlet collector at installation.

At the left: zaslonka of an inlet collector with changeable length of a path of the 2,8-liter 6-cylinder engine are given by means of the membrane mechanism noted by an arrow.

On the right: «the valve for switching of a consecutive inlet collector» (arrow) defines this, whether the rarefied air on the membrane mechanism can to get. The valve is located on the right behind in a motor compartment at an air flowmeter.

Models with the 2,8-liter 6-cylinder engine

The long inlet collector of small diameter provides a high torque already at low frequency of rotation. The short inlet collector, on the contrary, is necessary for high engine capacity at high frequency of rotation of its shaft with big cross-section section.

To combine one with another, engineers of Audi developed a new inlet collector with changeable length of a path. Depending on operating modes at it inside are closed and open six zaslonok. Thereby for each cylinder the inlet collector of different length and different cross-section section is provided: or an inlet collector for a torque (a long pipe with small diameter), or moshchnostny an inlet collector (a short pipe with big cross-section section). All six zaslonok are put in action by depression and copes depending on frequency of rotation: to 4000 rpm they remain closed for achievement of a high torque. Over 4000 rpm they completely open for achievement of high capacity. Below 4000 rpm by means of an inlet collector of a torque in comparison with a moshchnostny inlet collector about 30 N • are won by m.
The 2,8-liter engine develops the maximum torque of 245 N • m at 3000 rpm with a condition of application of AI-95 gasoline; with application AI-98 its torque raises to 250 N • m. In a wide range from 2000 rpm to 5500 rpm the torque of at least 220 N • m develops.

Check of action of an inlet collector

Switching of an inlet collector should be checked only in case the car does not develop the necessary capacity. For a start it is necessary to check manually a legkokhodnost of system of drafts and levers. Then turn of dough for action: it is necessary to check at the heated-up engine.


  1. To start the engine and to finish frequency of rotation to exceeding 4000 rpm.
  2. To watch the membrane mechanism of switching of an inlet collector:
    Draft of a drive should depart now back.
  3. If it not so, it is necessary to check vacuum hoses on tightness. If they as it should be:
  4. To check the membrane mechanism: to put on connection of the mechanism a spare vacuum hose, strong to involve a mouth.
  5. If draft does not move and/or so a lot of air is involved, the membrane mechanism is faulty. To replace. If mechanism as it should be:
  6. To check the valve of switching of an inlet collector with changeable length of a path: to remove from the valve both vacuum a hose. To put on a spare vacuum hose a tip to an inlet tube of the valve.
  7. Strongly to involve a mouth air from a spare vacuum hose. Retraction of air should be impossible (impassability).
  8. To get the engine, to finish frequency of rotation to much exceeding 4000 rpm.
  9. Again strongly to involve air a mouth. Now retraction of air should be possible (passableness).
  10. If still you could not find, where malfunction (that in itself is rather improbable) disappears, the workshop should be engaged in check of management.
  11. To remove protection of the engine.

Removal of an inlet collector 2,8 - the 6-cylinder engine


  1. To remove tips of spark plugs, to take out high-voltage wires from holders.
  2. To remove distributive топливопровод together with all vpryskny nozzles (head System of injection of MPI/MPFI).
  3. To remove an inlet air sleeve.
  4. To remove the valve of stabilization of idling or to disconnect the tip.
  5. To remove on an inlet collector and the case of throttle knot all vacuum hoses/hoses of system of ventilation of the case of a case.
  6. To remove a rope of "gas" and the tip of a potentiometer of a butterfly valve.
  7. To unscrew bolts in the sequence opposite to those that is shown in drawing above.
  8. To remove an inlet collector together with the case of throttle knot.
  9. Installation: to replace sealing laying.
  10. To tighten fixing bolts of an inlet collector according to specified in drawing at the top of sequence for four stages: First stage: 5 N • m, second stage: 10 N • m, third stage: 20 N • m, fourth stage: once again 20 N • m.

Removal of an inlet collector 2,6 - the 6-cylinder engine


  1. Logically removal occurs to identically similar process at the 2,8-liter engine.
  2. For sequence of an inhaling of fixing bolts it is necessary to use the same, as at the 2,8-liter engine.