Audi A3

since 1997 of release

Repair and car operation

Audi A3
+ Maintenance instruction
+ Current leaving and service
- Engine
   Compression check in engine cylinders
   Engine check by means of the vacuum gage
   Removal and installation of the bottom cover of an impellent compartment
   Removal and engine/RKPP installation
   + Four-cylinder petrol engines 1.6, 1.8 of l
   + Diesel engines
   - Major maintenance
      Measurement of cylinders
      Check, assembly and installation of shatunno-piston group
      Check of a cranked shaft
   + greasing System
+ Systems of cooling, heating
+ the Power supply system and production of the fulfilled gases
+ engine Electric equipment
+ Manual box of gear shifting
+ Automatic transmission and models with a full drive
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Elektroskhema

Check, assembly and installation of shatunno-piston group


1. All details should be checked well. If on details traces of furrows, dredging or wear are visible, it is necessary to replace them. It is necessary to make the following check of pistons:
2. Measure gaps of piston rings in flutes on height, establishing rings in turn in the corresponding flutes. The gap between a surface of a ring and a surface of a flute of the piston decides on the help flat щупа. If the gap of a ring exceeds 0.12 mm, means rings or pistons are worn-out. The nominal size makes 0.02–0.07 mm.
3. Insert one after another all piston rings from the bottom party of the block of cylinders into cylinders. By means of the overturned piston of a ring it is necessary to press approximately on 15 mm down. Thus both edges of a ring should be shifted to measure a gap in the ring lock.
4. Nominal rates are specified in Specifications. The limit of wear is also various for various piston rings.
5. At too small gap (for example if new), edges of a ring it it is necessary to grind off a ring, for this purpose it is necessary to clamp a file in a vice. At too big gap in the ring lock it is necessary to replace the corresponding ring.
6. Piston fingers and plugs of rods should be checked on wear and existence of the erased places. If at least one rod is unsuitable, it is necessary to replace all set.
7. Nuts of shatunny bearings should be replaced.
8. Rods should be checked on a bend and twisting in the special adaptation.
9. Check bolts of rods on existence of damages and if necessary replace. In this case rastyazhny bolts are applied, and it is necessary to replace them same.
Assembly of shatunno-piston group
10. If the oil nozzle for piston cooling acted in film, it should be turned together with a safety valve (27 N of m). Nozzles are located in the lower part of cylinders.
11. If pistons are replaced, it is necessary to check, that all pistons were one type.
12. Heat up pistons to temperature 60°С (put in hot water). It is necessary to take care of existence of the suitable tool which can be put to inside of a piston finger.
13. Press fingers by hand into warm pistons and in rods.
14. At assembly of pistons and rods it is necessary to fulfill the following requirement:

– The arrow on the piston bottom (or drawn or beaten out on the new piston) should be turned to the forward party of the engine.
– Cast ledges on a rod and a cover of the bearing should be turned to a pulley.
– Designations of numbers of cylinders on rods and covers of bearings should coincide.
15. Check, that after assembly the piston could shake freely on a rod if to move it in the arrow direction.
16. By means of flat-nose pliers for piston rings establish rings in flutes in turn. Both kompressionny rings can be mixed, and therefore it is necessary to check their section before installation. Besides, both kompressionny rings are marked on the one hand with a word of "Torahs" or “Oben” and this designation after installation of a ring should be read from above.
17. Establish the maslosjemny ring consisting of three parts, having distributed evenly locks.
Installation of shatunno-piston group
18. Well grease cylinders.
19. Spread out all rods according to numbers of cylinders. Cast ledges on rods and covers of bearings should be turned to a pulley of a cranked shaft.
20. Shooters on the bottom of pistons should point to the forward party of the engine.
21. Arrange locks of piston rings at identical distance on a piston circle, i.e. through 120 °.
22. Arrange a coupling tape for piston rings as it is represented on an illustration and press piston rings into flutes. Check, that they were well pressed.
23. Put on short pieces of rubber or plastic tubes rod hairpins not to scratch cylinders.
24. Turn a cranked shaft that two necks of a shaft were in situation NMT.
25. Move a rod into the cylinder from above. The engine for this purpose needs to be put on one side that it was possible to bring rods to necks of bearings and not to scratch thus cylinders or shatunny necks. The loose leaf of the shatunny bearing already should be thus in a rod, a ledge in dredging.
26. Move the piston while rings one behind another will not be moved into the cylinder, and the basis of a rod will sit down on a neck of a cranked shaft. Thus do not scratch a bearing neck.
27. Lay the loose leaf of the second bearing in a cover, well grease the loose leaf, dress a cover on hairpins of a rod and slightly hammer. Pieces of rubber tubes it is necessary previously remove. Surely it is necessary to pay attention to that cast ledges on a rod and a cover of the shatunny bearing coincided, differently at the last minute it is possible to make a mistake.
28. Grease surfaces of a prileganiye of nuts on covers of shatunny bearings with oil.
29. Tighten nuts of covers of shatunny bearings alternately the moment of 30 Nanometers and from this situation hold on for 90 °, i.e. on a turn quarter.
30. After a tightening of shatunny bearings it is necessary to examine each bearing once again. From experience it is known that defects of shatunny bearings are sometimes shown after the completion of repair when the cover of the bearing and a rod are not pulled together faultlessly. Figure 1 on an illustration designated both aforementioned cast ledges, and figure 2 – designations of a cover of the shatunny bearing and a rod, in this case for the second cylinder. The specified labels should settle down on all rods the friend opposite to the friend. Such check should be made surely before closing of a case of the engine.
31. After installation of rods the cranked shaft needs to be turned several times to define, whether there are no jammings. If is, it is necessary to check once again, whether there are pistons in the correct situation, i.e. shooters on the bottoms should be directed forward (towards a pulley).
32. By means of measuring щупа check a lateral gap of a rod to a cheek of a cranked shaft. Thus it is necessary to press the shatunny bearing to the right to measure a gap measuring the shchupy. It is an axial gap of the bearing of a rod, and it should not exceed 0.37 mm. Establish the case pallet.
The moment of an inhaling of bolts of fastening for them various.
33. From the forward party of the engine weaken bolts of a pulley of a cranked shaft (a damper of krutilny fluctuations), holding a flywheel.
34. On cars with automatic transmission unscrew a driving disk in the way described above.
35. Remove a head of cylinders together with the inlet pipeline and a final collector. Some details act in film already at engine removal (depending on its type).
36. Unscrew a pulley from the pump of cooling liquid and the bottom cover of a gear belt.
37. Mark the direction of rotation of a gear belt with paint from outer side.
38. After weakening of a nut of a tension of a belt remove a gear belt from drive and natyazhitel gear wheels. The camshaft (shaft) after that cannot be turned.
39. Unscrew the case pallet.
40. Remove the oil pump.
41. If it is necessary, remove only a cranked shaft, it is possible to leave pistons and rods in the block of cylinders. Otherwise it is necessary remove pistons and rods. If pistons and rods remain in the block, it is necessary to mark in the order of a cover of shatunny bearings, remove them and store together with loose leaves of bearings. Not to forget that it is necessary to replace the damaged rastyazhny bolts surely.
42. Establish a strelochny measuring instrument (indicator) on a support to the forward party of the block of cylinders or fix it by means of magnetic fastening on the block of cylinders, having put measuring щуп to a cranked shaft. By means of a screw-driver press a cranked shaft in one party, establish a strelochny measuring instrument on a zero and press a shaft in other party. The Strelochny measuring instrument will show an axial gap of a cranked shaft and this size it is necessary to write down. If it exceeds 0.25 mm, it should be considered at assembly. Loose leaves of average bearings are supplied with the adjusting half rings defining an axial gap.
43. If there is no available a strelochny measuring instrument, it is possible to measure a gap on the average bearing between a flange of the bearing and a surface of a cranked shaft by means of measuring щупа lezviyny type. For check measuring shchupy (thickness), a shaft it is necessary to wring out no more than 0.25 mm in one party.
44. Unscrew bolts of fastening of a sealing flange on the forward party of the engine and remove a flange with laying.
45. Remove an intermediate plate of the engine, unscrew bolts of a flange of an epiploon and remove a flange with an epiploon. The intermediate plate goes by means of directing plugs.
46. Weaken gradually cross-wise bolts of covers of bearings of a cranked shaft and remove them one after another. Check, that numbers of covers were well visible. The cover No. 1 is located from a pulley.
47. Remove loose leaves of bearings and radical necks and store them together with the corresponding covers of bearings. It is necessary to mean that one loose leaves are supplied with lubricant flutes, and others – are not present.
48. Carefully to take a cranked shaft from an engine case.
49. Take out the remained loose leaves from a case of the engine and store them together with other loose leaves and covers of bearings. These loose leaves are supplied with lubricant channels and at assembly should be again established in an engine case.
50. Remove the bottom half rings on the average bearing. It is necessary to mark them on lateral face.