Audi A3

Since 1997 of release

Repair and car operation

Audi A3
+ The maintenance instruction
+ Current leaving and service
- The engine
   Compression check in engine cylinders
   Check of the engine by means of the vacuum gauge
   Removal and installation of the bottom cover of an impellent compartment
   Removal and engine/rkpp installation
   + Four-cylinder petrol engines 1.6, 1.8 l
   + Diesel engines
   - Major repairs
      Measurement of cylinders
      Check, assemblage and installation of shatunno-piston group
      Check of a cranked shaft
   + Greasing system
+ Systems of cooling, heating
+ The power supply system and release of the fulfilled gases
+ Engine electric equipment
+ Manual box of a gear change
+ Automatic transmission and models with a full drive
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Electroschemes

Check, assemblage and installation of shatunno-piston group


1. All details should be checked up well. If on details traces of furrows, dredging or deterioration are visible, it is necessary to replace them. It is necessary to make the following check of pistons:
2. Measure backlashes of piston rings in flutes on height, establishing rings by turns in corresponding flutes. The backlash between a surface of a ring and a surface of a flute of the piston is defined by means of flat probeа. If the ring backlash 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 turned piston of a ring it is necessary to press approximately on 15 mm downwards. Thus both edges of a ring should be shifted to measure a backlash in the ring lock.
4. Rating values are specified in Specifications. The deterioration border also is various for various piston rings.
5. At too small backlash (for example if new), ring edges 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 backlash in the ring lock it is necessary to replace a corresponding ring.
6. Piston fingers and plugs of rods should be checked up on deterioration and presence of the erased places. If at least one rod is unsuitable, it is necessary to replace all complete set.
7. Nuts шатунных bearings should be replaced.
8. Rods should be checked up on a bend and twisting in the special adaptation.
9. Check up bolts of rods on presence of damages and if necessary replace. In this case are applied растяжные bolts, and it is necessary to replace them same.
Assemblage 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 Н). Nozzles are located in the bottom part of cylinders.
11. If pistons are replaced, it is necessary to check up, that all pistons were one type.
12. Heat up pistons to temperature 60С (put in hot water). It is necessary to take care of presence of the suitable tool which can be put to an inside of a piston finger.
13. Press fingers by hand in нагретые pistons and into rods.
14. At assemblage of pistons and rods it is necessary to fulfil the following requirement:

– The arrow on the piston bottom (either 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 bearing cover should be turned to a pulley.
– Designations of numbers of cylinders on rods and covers of bearings should coincide.
15. Check up, that after assemblage the piston could shake freely on a rod if to move it in an arrow direction.
16. By means of flat-nose pliers for piston rings establish rings in flutes by turns. Both компрессионных rings can be mixed, and therefore it is necessary to check up their section before installation. Besides, both компрессионных rings are marked on the one hand by a word of "Torahs" or “Oben” and this designation after ring installation should be read from above.
17. Establish маслосъемное a ring consisting of three parts, having distributed in regular intervals 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. Arrows on the bottom of pistons should specify in the forward party of the engine.
21. Arrange locks of piston rings on 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 up, that they have been 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 position НМТ.
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 шатунные a neck. The loose leaf шатунного the 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 rod basis 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 preliminary remove. Necessarily it is necessary to pay attention to that cast ledges on a rod and a cover шатунного the bearing coincided, differently at the last minute it is possible to make an error.
28. Grease surfaces прилегания nuts on covers шатунных bearings with oil.
29. Tighten nuts of covers шатунных bearings alternately the moment of 30 Nanometers and from this position hold on for 90 , i.e. on a turn quarter.
30. After a tightening шатунных bearings it is necessary to examine each bearing once again. From experience it is known that defects шатунных bearings are sometimes shown after the repair termination when the cover of the bearing and a rod are not pulled together faultlessly. Figure 1 on an illustration designates both aforementioned cast ledges, and figure 2 – cover designations шатунного the 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 necessarily before closing картера the engine.
31. After installation of rods the cranked shaft needs to be turned some times to define, whether there are no jammings. If is, it is necessary to check up once again, whether there are pistons in correct position, i.e. arrows on the bottoms should be directed forward (towards a pulley).
32. By means of measuring probeа check up a lateral backlash of a rod to a cheek of a cranked shaft. Thus it is necessary to press шатунный the bearing to the right to measure a backlash measuring probeом. It is an axial backlash of the bearing of a rod, and it should not exceed 0.37 mm. Establish the pallet картера.
The moment of an inhaling of bolts of fastening for them various.
33. From the forward party of the engine ослабьте bolts of a pulley of a cranked shaft (демпфера крутильных fluctuations), keeping a flywheel.
34. On cars with automatic transmission turn on приводной a 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. Turn away a pulley from the pump of a cooling liquid and the bottom cover of a gear belt.
37. Mark a direction of rotation of a gear belt with a paint from an outer side.
38. After easing of a nut of a tension of a belt remove a gear belt from gear wheels of a drive and натяжителя. The Camshaft (shaft) after that cannot be turned.
39. Turn away the pallet картера.
40. Remove the oil pump.
41. If it is necessary, remove only a cranked shaft, pistons and rods can be left 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 шатунных bearings, remove them and store together with loose leaves of bearings. Not to forget that damaged растяжные it is necessary to replace bolts necessarily.
42. Establish стрелочный a 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 probe to a cranked shaft. By means of a screw-driver press a cranked shaft in one party, establish стрелочный a measuring instrument on a zero and press a shaft in other party. The strelochnyj measuring instrument will show an axial backlash of a cranked shaft and this size it is necessary to write down. If it exceeds 0.25 mm, it should be considered at assemblage. Loose leaves of average bearings are supplied by the adjusting half rings defining an axial backlash.
43. If is not present available стрелочного a measuring instrument, it is possible to measure a backlash on the average bearing between a flange of the bearing and a surface of a cranked shaft by means of measuring probeа лезвийного type. For check measuring probeом (thickness no more), a shaft it is necessary to wring out than 0.25 mm in one party.
44. Turn away bolts of fastening of a sealing flange on the forward party of the engine and remove a flange with a lining.
45. Remove an intermediate plate of the engine, turn away bolts of a flange of an epiploon and remove a flange with an epiploon. The intermediate plate goes by means of directing plugs.
46. Loosen the gradually cross-wise bolts of covers of bearings of a cranked shaft also remove them one after another. Check up, that numbers of covers were well visible. The cover №1 is located from outside a pulley.
47. Remove loose leaves of bearings and radical necks and store them together with corresponding covers of bearings. It is necessary to have in view of that one loose leaves are supplied by lubricant flutes, and others – are not present.
48. Cautiously to take a cranked shaft from картера the engine.
49. Take out the remained loose leaves from картера the engine and store them together with other loose leaves and covers of bearings. These loose leaves are supplied by lubricant channels and at assemblage should be again established in картер the engine.
50. Remove the bottom half rings on the average bearing. It is necessary to mark them on a lateral face.

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