Cleaning and check of a condition of a head of cylinders and components. BMW the 5th E28/E34 series (from 1981 to 1993 of release)
Repair of BMW E28 and series E34 from 1981 to 1993
1. Cars of the BMW brand of 5-series
2. Engine
2.1. The repair work which is carried out without extraction of the engine from the car
2.2. Procedures of major maintenance of components of the engine
2.2.1. General information
2.2.2. General information about major maintenance of the engine
2.2.3. Check of extent of compression
2.2.4. Ways of removal of the engine and precautionary measure
2.2.5. Removal and engine installation
2.2.6. Options of major maintenance of the engine
2.2.7. An order of dismantling of the engine at major maintenance
2.2.8. Dismantling of a head of cylinders
2.2.9. Cleaning and check of a condition of a head of cylinders and components
2.2.10. Service of valves
2.2.11. Assembly of a head of cylinders
2.2.12. Removal of pistons / rods
2.2.13. Removal of a cranked shaft
2.2.14. Removal and check of a condition of an intermediate shaft
2.2.15. Cleaning of the block of cylinders
2.2.16. Check of a condition of the block of cylinders
2.2.17. Honingovaniye of cylinders
2.2.18. Check of a condition of pistons / rods
2.2.19. Check of a condition of a cranked shaft
2.2.20. Check of a condition of radical and shatunny bearings
2.2.21. Engine balance of assembly at major maintenance
2.2.22. Installation of piston rings
2.2.23. Installation of an intermediate shaft
2.2.24. Installation of a cranked shaft and check of lubricant gaps of radical bearings
2.2.25. Installation of a back epiploon of a cranked shaft
2.2.26. Installation of pistons / rods in collecting and check of lubricant gaps in bearings of rods
2.2.27. Start and an engine running in after major maintenance
2.2.28. Diagnostics of malfunctions of the engine
3. Cooling system
4. Power supply system
5. Ignition system
6. Control systems of the engine and decrease in toxicity of the fulfilled gases
7. System of production of the fulfilled gases
8. Coupling
9. Manual box of gear shifting (RKPP) and automatic transmission (AT)
10. Transmission line
11. Steering and suspension bracket
12. Brake system
13. Body
14. Control body sizes
15. Heater and air conditioner
16. System of onboard electric equipment
17. Routine maintenance of the car
18. Size table and adjusting data
19. Schematic electric circuits
20. Governing bodies and operation receptions
21. System of onboard diagnostics - a principle of functioning and codes of malfunctions


2.2.9. Cleaning and check of a condition of a head of cylinders and components

Careful cleaning of a head (heads) of cylinders and the related components of the valve with the subsequent detailed check of a condition will allow to define, what amount of works with valves should be executed at major maintenance of the engine.

If the engine was tested by a strong overheat, a head of cylinders, probably, is bent (look item 4).



  1. Remove with a scraper from condensed surfaces of a head of cylinders, the inlet pipeline and a final collector all remains of old laying and a sealing compound. Observe extra care not to damage a head of cylinders. In shops of auto parts it is possible to get special solvents for removal of laying.
  2. Remove from cooling channels everything sedimentation.
  3. Rigid brush clean various openings to remove sedimentation which could appear in them.
  4. For removal of corrosion and carving hermetic which can be present at carving openings, clean them taps of the corresponding size. If the compressed air is available, after this operation clear with its help of an opening of garbage.

When using the compressed air apply goggles.

  1. Clear solvent a head of cylinders and carefully dry. The compressed air will accelerate process of drying and will provide purity of openings and deepenings.

There are chemical means for removal of a deposit and they can appear very useful when cleaning heads of cylinders and components of knots of valves. However, these means very aggressive and them should be applied with care. Follow instructions on their packings.

  1. Clear solvent shaft yokes/yokes/pushers, springs, springs of valves, holders and crackers, and then carefully dry them. Not to mix components of valves, clear valves in turn.

Do not clear M40 engine hydropushers; leave them completely shipped in oil.

  1. Remove a scraper from valves everything sedimentation, and then with an electric brush remove from heads and cores of valves a deposit. Again track, that components of valves were not mixed.

Condition check

Before making decision on need of works of a mechanical workshop be convinced that all specified checks of a condition are executed. Make the list of checks.

Head of cylinders


  1. Carefully examine a head about cracks, traces of leakage of a cooler and other damages. At detection of cracks address for consultation in a mechanical workshop. If repair is impossible, it is necessary to get a new head of cylinders.
  1. By means of a measuring instrument of planeness and щупов check existence of a curvature by condensed laying of a surface of a head. If curvature exceeds the limit given in the Size table and adjusting data at the end of the Management, it is possible for grinding in a mechanical workshop provided that the thickness of a head will not appear less admissible.
  1. Examine saddles of valves of each chamber of combustion. If they have considerable dents, cracks or прогары, the head will demand the service which is falling outside the limits possibilities of a house workshop.
  1. Check a gap between a core of the valve and directing, having measured by the tsiferblatny indicator a lateral deviation of a core. The valve should be in directing and at height about 2 mm over a saddle. A full deviation of a core of the valve, measured by the indicator, it is necessary to divide into two to receive the valid value of a gap. If after that there are doubts concerning a condition of directing valves, they should be checked in a mechanical workshop (the price of this service is minimum).



  1. Attentively check a surface of each valve in search of non-uniform wear, deformation, cracks, dents and obgoraniye zones. Will check a valve core about an istiraniye, and a core neck - on existence of cracks. Povrashchayte the valve also check existence of an appreciable curvature. Check existence on the end of a core of dents and excessive wear. Existence of any of these defects indicates need of service of valves as Service of valves is described in the Section.
1 — the valve End
2 — the Flute under crackers
3 — the Core (the worn most out part)
4 — the Core (the worn most out part)
5 — a valve Facet
6 — the Eminence
  1. Measure size of an eminence of each valve. The valve with smaller, than is required, an eminence, is subject to replacement

Components of valves


  1. Check wear on the ends of all springs. Before deciding to use springs in the restored engine, it is necessary to check their rigidity (for this check send springs in a mechanical workshop) by means of the special adaptation.
  1. Establish each spring on an equal surface and check their vertical position. If any of springs is bent or warped or, probably, has the broken round, replace springs.
  1. Check holders of springs and crackers on existence of obvious wear tracks and cracks. It is necessary to replace any suspicious details, otherwise, if they fail at operation of the engine, there will be considerable damages.

Yokes (engines M10, М20 and М30)

Yokes of final valves are most subject to wear and they should be checked with special care.


  1. Check yokes about excessive wear on the ends which contact to a core of the valve and a camshaft.
  1. Check a radial gap (look the Section Dismantling of a head of cylinders). If it is too great, either the yoke plug, or a shaft (or both) are worn-out. For the definition, what element is more worn-out, shift on some distance a yoke on a shaft and again measure a radial gap. If the gap corresponds now to requirements, that, possibly, the shaft is the most worn-out component. If the gap does not correspond to requirements, plugs of yokes are subject to replacement.

Shaft of yokes (engines M10, М20 and М30)

Check shaft on existence задиров, excessive wear and other damages. Surfaces of contact of yokes with shaft should be smooth. If on border of contact of a yoke with shaft there is a ledge, a shaft, probably, is worn-out.

Hydropushers (M40 engine)


  1. Check wear existence, задиров and dents on pushers where they contact with the ends of cores of valves and fingers. If there is a considerable wear of pushers and a camshaft, it is necessary to get a new camshaft together with pushers.
  2. Similarly check hydropushers where they contact to wells in a head of cylinders, on wear existence, задиров and dents. Sometimes hydropushers create noise at work and replacement demand, and it becomes appreciable at operation of the engine. To find internal damage or wear of a hydropusher when it is removed, quite difficult; in case of doubts, it is necessary to establish a set of new hydropushers.



  1. Check camshaft necks (round surfaces of sliding) and cams on existence задиров, dents, chips and excessive wear. Measure by a micrometer height of each inlet and final cam. Compare height of all inlet and final cams. If results of measurements on all inlet or final cams differ more, than on 0.08 mm or if on a camshaft any signs of wear are found, replace a camshaft.
  2. Check a condition of surfaces of bearings of sliding in a head of cylinders on existence задиров and other damages. If surfaces of bearings have teases or are damaged, usually make replacement of a head of cylinders as bearings are the processed surfaces in a head of cylinders.

Mechanical workshop (in particular, specializing on BMW) or office of the dealer can offer alternative to replacement of a head of cylinders option if the unique problem are insignificant scratches of surfaces of bearings of a camshaft.

  1. Measure by a micrometer of a neck of a camshaft and write down results of measurements.
  1. By telescopic measuring instrument or micrometer - a nutromer measure in a head of cylinders diameters of bearings of a camshaft (on the M40 engine previously establish covers of bearings). For receiving size of a lubricant gap from the size of a neck of a camshaft subtract internal diameter of the corresponding bearing. Compare a lubricant gap to the value given in the Size table and adjusting data at the end of the Management. If it does not correspond, the new head of cylinders and/or a new camshaft is required.

Before installation of a new head of cylinders check former in a mechanical workshop (especially, in specializing on BMW). Probably they can restore it.

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2.2.8. Dismantling of a head of cylinders
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2.2.10. Service of valves