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





Works on a gear belt

The gear belt on the 6-cylinder engine will be pulled correctly if it is possible to turn it fingers a boundary a gear wheel of the drive of a gear belt and the top directing roller no more than on 90o.


In the engine with a working volume of 1,8 l the top cover of a gear belt too fastens clips (2 and 3). At installation ledges (1) below on a cover have to be correctly inserted into the lower part of a cover.


Big efforts are demanded by work on dismantle of the lower cover of a gear belt in the engine with a working volume of 1,8 l. Figures (1–4) designated an arrangement of fixing bolts.


Here both pistons (1 and 2) of the mechanism of a tension of a gear belt in four-cylinder engines are shown.

At the left: a tension roller of a gear belt at the four-cylinder engine. Are designated by figures:

1 – a wrench with two openings for installation of a tension of a gear belt (the text above);
2 – fixing bolt.

On the right: the tension roller at the six-cylinder engine is in quite hidden place on the right ahead on the motor block. The arrow showed tightening a bolt.

On the dismantled engine with a working volume of 1,8 l the arrangement of some knots is visible

1 – belt pulley of the crankshaft;
2 – tension roller of a gear belt;
3 – pulley of a gear belt of a cam-shaft;
4 – Hall sensor;

5 – gear belt;
6 – the device for a tension of a poliklinovy belt;
7 – radiator fan bearing;
8 – pulley of a maple belt of the water pump.

At the left: the engine with a working volume of 1,8 l. The mark of BMT (2) in a pulley of a gear belt of a cam-shaft and the mark (1) in a cover of a head of the block of cylinders corresponding to it have to be opposite to each other the same as a mark of BMT (4) in a belt pulley of the crankshaft and the arrow (3) corresponding to it in the lower cover of a gear belt.

On the right: at the engine with a working volume of 1,6 l the mark in a pulley (2) gear belts of a cam-shaft has to correspond to a mark in the form of an arrow (1) in a back cover of a gear belt. Crankshaft VMT in the same situation, as in the engine with a working volume of 1,8 l.

As the silent driving element which is located from above a cam-shaft(s) the gear belt which is set in motion the crankshaft serves.

The gear rubber belt from a steel wire works with an insert without wear, thus rubber mix of a gear belt provides dry greasing of belt pulleys. The gear belt except a cam-shaft serves in the 6-cylinder engine as the drive of the water pump. In the 4-cylinder engine the belt in addition puts in action an intermediate shaft which in turn serves as the drive of the oil pump and the distributor of ignition (only in 1,6 l the engine).

 Council: For work on a gear belt the car with the four-cylinder engine has to be given to so-called service situation (the head Detali of a body). Thus the frontal part is removed from the car and is taken away on some distance by means of bolts. For the purpose of access improvement we recommend to you to dismantle also a gear belt in the 6-cylinder engine.

Dismantle of a cover of a gear belt

 PERFORMANCE ORDER

  1. Four-cylinder engine: dismantle an airintaking hose, having unscrewed two screws with crosswise heads on frontal part of the car.
  2. Wring out above on a cover two fixing collars.
  3. Remove the top part of a cover up.
  4. At installation track that the cover was correctly inserted by bottom edge into an opposite detail, otherwise it will not be reliably recorded.
  5. In most cases it is enough to dismantle the top part of a cover. To dismantle also lower part of a cover, more difficult.
  6. Bring frontal part of the car into service situation (the head Detali of a body).
  7. Dismantle the viscous fan (the head the Cooling system).
  8. Take off a klinovo-ridge belt and unscrew the belt tension mechanism.
  9. Unscrew a pulley of a klinovo-ridge belt at the crankshaft and a pulley of a klinovo-ridge belt of the water pump.
  10. Weaken fixing bolts or nuts of the lower cover of a gear belt and remove it.
  11. At installation bolts are tightened as follows: a pulley of a klinovo-ridge belt at the crankshaft with the moment of an inhaling of 25 Nanometers (watch fixing), pulleys of a klinovo-ridge belt at the water pump on 20 Nanometers, nuts or bolts of a cover of a gear belt on 10 Nanometers.
  12. 6-cylinder engine: dismantle the viscous fan.
  13. Dismantle a klinovo-ridge belt with a tension roller of a klinovo-ridge belt.
  14. Weaken from above and from below on each half of a cover of a gear belt on one coupling collar.
  15. Carefully take out a cover from other hooks.

Check of a condition of a gear belt

 PERFORMANCE ORDER

  1. Uncover a gear belt.
  2. The gear belt should not be greasy or cracked.
  3. Lateral faces of teeth have to be serviceable and not bear of wear tracks.
  4. In order that you could examine a belt on all length, turn a cranked shaft as it is described in the head further.
  5. Surely replace the damaged gear belt.

Check of a tension of a gear belt

The four-cylinder engine has a spring roller for a tension of a gear belt which automatically creates the necessary tension of a belt. In this regard only the belt tension mechanism is checked. The six-cylinder engine has a static tension of a belt.

 PERFORMANCE ORDER

  1. Four-cylinder engine: remove the top cover of a gear belt.
  2. Press a belt between pulleys and observe a spring tension roller: the tension roller has to be wrung out thus and at a belt otpuskaniye again to return to a starting position. In this case belt tension mechanism as it should be.
  3. Check by means of a mirror, in what range of a scale there is an edge of the piston.
  4. Range "And": everything is all right.
  5. Range "In": normal area of wear; adjustment can remain.
  6. Range "With": adjustment of the mechanism is necessary (see the following section) or there is a defect in a gear belt or in a tension roller.
  7. Six-cylinder engine: uncover a gear belt.
  8. Take measurement between a pulley of a cam-shaft and the top by-pass roller on the right side of cylinders if to look in the direction of travel.
  9. The cold gear belt at the correct tension has to turn on 90 ° (= to a right angle) only big and index fingers.

Installation of a tension of a gear belt

4-cylinder engine

Installation is made at the cold and heated-up engine by a wrench with two openings, for example Hazet 2587.

 PERFORMANCE ORDER

  1. Remove the top cover of a gear belt, weaken a fixing bolt.
  2. Turn the device of a tension of a gear belt a wrench so that the 1 piston completely started and the 2 piston raised the tension device approximately on 1 mm.
  3. Tighten a hand a fixing bolt of a tension roller in the beginning.
  4. Turn a cranked shaft on two turns in the direction of the movement (to the right).
  5. Check, whether range "And" on a scale opposite to the upper edge of the 2 piston settles down.
  6. If it cannot be made because of bad access, it is possible to measure "D" = 25–29 mm.
  7. If installation does not meet standard yet, pull also for check again turn a cranked shaft.
  8. At the correct installation tighten a fixing bolt of a tension roller with the moment of an inhaling of 25 Nanometers.
  9. Turn the crankshaft on one turn and double-check a tension of a gear belt.

Installation of a tension of a gear belt

6-cylinder engine

 PERFORMANCE ORDER

  1. In the beginning uncover a gear belt.
  2. Dismantle a klinovo-ridge belt and the device of its tension.
  3. Weaken tightening a bolt (with an internal hexagon of 8 mm) on a tension roller.
  4. Turn a key with an internal hexagon 8 mm a tension roller to the right down to that time until the tension of a belt becomes correct.
  5. Keep a tension roller in this situation.
  6. Key with an internal hexagon of 8 mm tighten tightening a bolt of a tension roller (45 Nanometers).
  7. Turn the crankshaft on one turn and double-check a tension of a gear belt.

Replacement of a gear belt, installation of phases of gas distribution

The description of process of replacement of a gear belt belongs not only directly to this work, but also to dismantle and installation of a head of the block of cylinders, thus the gear belt inevitably has to be removed.

Installation of a gear belt according to the logic of things assumes also installation of phases of gas distribution. But to avoid delusion, it is necessary to remember that phases of gas distribution do not change as a result of wear. Installation is made only once if before it the gear belt was removed.

 Council: Only at the correct installation of phases of gas distribution the coordinated work of valves and the gas-distributing mechanism is ensured. Incorrectly established phases of gas distribution are the reason of low engine capacity and as a last resort can even lead to the heaviest damages of the engine when the basis of the piston beats on out of time closed valves. Installation in different types of engines is made differently.

Audi does not provide replacement of a gear belt within regular maintenance of the car any more. Nevertheless all of us would replace a belt after 150 000 km of run. If the gear belt tears, the new engine will be necessary. In comparison with it preventive replacement of a gear belt costs kopeks.

Whether it is possible to make it by own efforts?

Replacement of a gear belt puts different problems depending on engine model:

  • At the four-cylinder engine replacement of a gear belt represents in general a laborious work, but professionally not a component of too bigger problem. Thus special tools are not necessary.
  • At the six-cylinder engine for installation of phases of gas distribution (that becomes necessary after dismantle of a gear belt and a head of the block of cylinders) it is necessary to record absolutely precisely cam-shafts and the crankshaft in situation VMT by means of special tools (tools 3242 and 3243). You have to get the mentioned tools.

Replacement of a gear belt

4-cylinder engine

 PERFORMANCE ORDER

  1. Bring frontal often the car into service situation (the head Detali of a body).
  2. Dismantle the viscous fan.
  3. Take off maple and klinovo-ridge belts, unscrew the device of a tension of a belt (section Generator).
  4. Dismantle a pulley of a klinovo-ridge belt at the crankshaft after weakening of a bolt with an internal hexagon (not the central bolt).
  5. Unscrew a pulley of a maple belt of the water pump.
  6. Dismantle the top part of a cover of a gear belt.
  7. Weaken fixing bolts and nuts of the lower cover of a gear belt and remove it.
  8. Put the piston in the cylinder 1 in the provision of ignition in VMT, see above in this chapter.
  9. Designate the direction of the movement on a gear belt for the subsequent installation. Keep the same direction of the movement of the belt which was in the use.
  10. Weaken fixing bolts of a tension roller and take off a gear belt.
  11. Impose a new gear belt. If the provision of a pulley of the crankshaft and a cam-shaft did not change, phases of gas distribution of valves are still established correctly. Safety for the sake of nevertheless them need to be checked before final assembly:
  12. Turn a pulley of a gear belt of a cam-shaft so that marking of a pulley rose under an arrow on a back cover of a gear belt (the engine with a working volume of 1,6 l) or under a mark in a cover of a head of the block of cylinders (the engine with a working volume of 1,8 l).
  13. If now it is necessary to turn a cam-shaft, it can be made only when the piston is in situation VMT, otherwise it is possible to damage valves or the bases of pistons.
  14. The mark of VMT of the crankshaft is checked through a viewing opening on a transmission.
  15. At the engine with a working volume of 1,6 l check also the provision of an intermediate shaft. For this purpose uncover the distributor of ignition and check, whether points a distributor finger to a tag in edge of its case. If is not present, turn an intermediate shaft so that tags coincided.
  16. Impose a gear belt, thus watch that the provision of various pulleys did not change.
  17. Pull a gear belt as it is described above.
  18. For all models: completely turn a cranked shaft two times and still check installation.
  19. Screw the lower cover of a gear belt with the moment of an inhaling of 10 Nanometers.
  20. Fix a pulley of a poliklinovy belt of a cam-shaft with the moment of an inhaling of 25 Nanometers. Thus track the correct provision of a cover: depending on model of the engine or the fixing pin has to enter a belt pulley, or fixing openings of a belt pulley are located asymmetrically. In this case all fixing openings have to coincide with openings on the crankshaft.
  21. Other assembly is made, respectively, as it should be, the return to dismantle.
  22. The engine with a working volume of 1,6 l: adjust ignition.

Replacement of a gear belt

Six-cylinder engine

 PERFORMANCE ORDER

  1. Dismantle poliklinovy a belt together with the tension device (section Generator).
  2. Dismantle covers of a gear belt on both parties.
  3. Turn the crankshaft in the provision of ignition in cylinder 1 VMT. Marks in a belt pulley of the crankshaft and a cover of a gear belt have to coincide, big openings on the fixing plates on pulleys of cam-shafts have to be turned to each other to the center of the engine.
  4. Unscrew the sensor of the moment of ignition from a case and instead of it screw in the special
    Fastening of the Crankshaft 3242 tool. Slightly tighten.
  5. Dismantle a pulley of a poliklinovy belt of the crankshaft, unscrew the lower cover of a gear belt.
  6. Note the direction of the movement of a gear belt for the subsequent installation. Keep the same direction of the movement of the belt which was in the use.
  7. Weaken a tension roller of a gear belt, take off a gear belt.
  8. Installation: install the special tool "Fastening of a Cam-shaft 3243" on the fixing plates of cam-shafts.
  9. Weaken bolts of pulleys of cam-shafts approximately only on three turns.
  10. Again dismantle the special tool 3243.
  11. Remove both pulleys of a cam-shaft from a cone. Use nippers for this purpose. Establish holding straps on a reverse side of a nave of a pulley of a gear belt; the bolt remains as was (weakened on three turns).
  12. After completion of preliminary works installation begins now:
  13. For carrying out further work it is necessary to impose a new gear belt now. When imposing the belt which was in the use consider the direction of its movement.
  14. Again install the special tool "Fastening of a Cam-shaft 3243" on the fixing plates of cam-shafts.
  15. Double-check correctness of installation of the special tool.
  16. Pulleys of cam-shafts have to be put on a cone so that they rotated on a shaft, but were not shaken (the bolt is screwed up manually).
  17. Now pull a gear belt (see in the head above).
  18. Tighten pulleys of cam-shafts with the inhaling moment on 30 Nanometers and then finally tighten bolts on 1/2 turns (180 °).
  19. Remove the special tool.
  20. Mount again the dismantled details.

At the left: in drawing installation of the special tool 3243 for fixing of cam-shafts is shown in the provision VMT at the six-cylinder engine.

On the right: here the tool 3242 and a place in which it is screwed in in the block of cylinders for fixing of a cranked shaft is shown.


To install the special tool 3243, it is necessary to unscrew from a case (1) sensor of the moment of ignition (2) six-cylinder engines.


Removal of a pulley of a gear belt of a cam-shaft by means of a stripper at the weakened fixing bolt.