BMW 3 series E30

Since 1983-1994 of release

Repair and car operation

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

THE GENERAL DATA

Now our motorist faces to a problem – it is necessary to choose. And to choose too it is uneasy, after all the market of automobile filters is great. The filter is not the engine and not коленвал what difference who has made it also what it designs if only the functions carried out, yes 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 consists that an unsuccessful choice such малости 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.

Appointment of the air filter as clearly all: to block access of a dust and to dust in a working cavity of the cylinder. Hit there small particles causes intensive deterioration, and as consequence – increase in backlashes between the piston and a cylinder wall.

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

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

The INTERNAL GRID – it is necessary only in the event that sealing trailer disks are executed from not elastic rigid material as is that element which helps to keep a surface прилегания a sealing ring enough the equal. But if on case covers there are dents the grid will disturb only, holding rigidity of a design and interfering with that the sealant has filled these backlashes and has prevented receipt of crude air.

TRAILER SEALING DISKS – their appointment, first of all, to promote absolute consolidation at a filter clip in the case, not to admit that the dirt has passed by a filtering curtain. If the material of which sealing trailer disks are made, is elastic, also 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 inquiry

The basic defects which are supposed at manufacturing of air filters, leaders to premature failure of the engine:

 – Use of a poor-quality filtering paper;
 – The small area of a filtering curtain (leads to a premature contamination and, as consequence, capacity falls and the fuel expense raises);
 – Incorrectly picked up material of sealing disks (insufficiently elastic, fragile at low temperatures);
 – A wrong profile of sealing disks (leads to impossibility dense прилегания to the case).

Usually the automobile owner does not penetrate into subtleties of a design of the filter and in own way chooses the filter approaching for it.

Researches have shown that at a choice of the filter of buyers interest:

 – Reliability of a filtration;
 – The reasonable price;
 – A trade dress;
 – The known trade mark.