E30 series BMW 3

since 1983-1994 of release

Repair and car operation

+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engine
+ 4. Cooling system
+ 5. Heating and ventilation
+ 6. Fuel system
+ 7. Exhaust system
+ 8. Transmissions
+ 9. Coupling
+ 10. Brake system
+ 11. Running gear
+ 12. Body
+ 13. Electric equipment
- 14. Good advice
   14.2. Changed numbers
   14.3. Purchase of the old car or mysterious set of figures and letters
   14.4. Durability of the car
   14.5. About parallelism of bridges of the car and the trailer
   14.6. Preparation of the car for winter
   14.7. Rule 35
   14.8. Choice of the second-hand car
   14.9. Engine oils
   14.10. That it is necessary to know, changing oil
   14.11. Emergence in deposit oil
   14.12 whether. It is possible to mix import oils?
   14.13. "Eats" much, but silently goes
   14.14. It is rather live, than it is dead …
   14.15. It is not got - good advice
   14.16. Visit to car-care center
   14.17. A gear belt for a drive of the mechanism of a gazoraspredeleniye
   14.18. Wear of pistons
   14.19. Valves
   14.20. Bearings of engines
   14.21. Engine pollution
   14.22. As the conditioner works and what to do, if it failed
   14.23. Conditioner: not only "pluses", but also "minuses"
   14.24. Rules of service of the conditioner
   14.25. It is not necessary to stir antifreeze with antifreeze …
   14.26. That it is necessary to know upon purchase of the air filter
   14.27. Engine overheat
   14.28. That it is necessary to know to the owner of the car with the injector engine
   14.29. Accumulator
   14.30. Possible malfunctions of the storage battery
   14.31. What to do with the failed generator
   14.32. The belt is guilty, and we blame the generator
   14.33. Catalyst
   14.34. Rub in one - or how to save the catalyst
   14.35. Probuksovochka
   14.36. Features of operation of brake system
   14.37. Malfunctions of brake system
   14.38. Brake liquids
   14.39. ABS: natural choice
   14.40. Rims
   14.41. We update rims
   14.42. Scheme of marking of a car tire
   14.43. Metal corrosion
   14.44. Automake-up
   14.45. What creaks?
   14.46. Hatch
   14.47. Safety cushion: troubles or pleasures?
   14.48. We fit well?
   14.49. Anticreeping "immunodeficiency"
   14.50. Why headlights grow dull
   14.51. "Galogenki"
   14.52. About the correct adjustment of headlights
   14.53. Electric motor
   14.54. From change of places "composed" changes nothing?


14.26. That it is necessary to know upon purchase of the air filter


Now our motorist faces a problem – it is necessary to choose. And to choose too it is difficult, after all the market of automobile filters is great. The filter is not the engine and not the crankshaft what difference who made it also what it designs if only the functions carried out and cheaply cost.

From time to time there are novelties in which new designs and materials are used, but happens that they at all have no quality certificate.

The trouble is that an unsuccessful choice of such malost as, for example, the air filter to which and the price of 5 dollars, can ruin the engine, and here already expenses are measured not by units, and thousand dollars.

Purpose of the air filter clearly all: to block access of a dust and to garbage in a working cavity of the cylinder. Hit there small particles causes intensive wear, and as a result – increase in gaps between the piston and a cylinder wall.

Let's consider a design of the ordinary air filter.

The FILTERING CURTAIN is the main working part of any filter, but the filter will not carry out the functions if it will not be dense, without gaps to become in the case.

The INTERNAL GRID – it is necessary only if sealing trailer disks are executed from an inelastic rigid material as is that element which helps to keep a surface of a prileganiye of a sealing ring of rather equal. But if on covers of the case there are dents, the grid will disturb only, holding rigidity of a design and interfering with that the sealant filled these gaps and prevented intake of crude air.

TRAILER SEALING DISKS – their appointment, first of all, to promote absolute consolidation at a filter clip in the case, not to allow that dirt passed by a filtering curtain. If the material of which sealing trailer disks are made, is elastic, and the grid in the filter is not necessary – rigidity of a design is reached by means of edges of rigidity of the goffered filtering curtain. The elastic sealant without hindrances blocks all cracks and roughnesses on case surfaces.


The main defects which are allowed when manufacturing the air filters, conducting to premature failure of the engine:

 – use of poor-quality filtering paper;
 – the small area of a filtering curtain (leads to a premature contamination and, as a result, the capacity falls and fuel consumption raises);
 – incorrectly picked up material of sealing disks (insufficiently elastic, fragile at low temperatures);
 – the wrong profile of sealing disks (leads to impossibility of a dense prileganiye to the case).

Usually the car owner does not penetrate into subtleties of a design of the filter and in own way chooses the filter suitable it.

Researches showed that at a choice of the filter of buyers interest:

 – reliability of a filtration;
 – reasonable price;
 – trade dress;
 – known trademark.