BMW 3 Series E30

since 1983-1994 release

Repair and operation of the car

Practical advice for professionals

It is possible to reanimate any "tired" car. But technical difficulties at the same time are big. Without spare parts, any machine park, welding and other technological support not to manage here. The main thing – factory instructions for repair (they are available now) tell nothing about possible alternative decisions, especially about choice problems among details, materials and tools which are in today's domestic market. Such is a circle of questions which both the loner enthusiast, and mechanics of "small service" lack for information. We also want it in process of opportunities to fill.

Sooner or later any engine becomes a source of troubles: becomes deaf in way, it does not want to be started in the mornings, pulls worse, "eats" excess fuel and oil. It is quite probable that the reason of his whimsical behavior is plain: it is enough to clean the carburetor, to adjust ignition and to replace oil scraper caps that everything entered norm. But happens that traditional approaches do not help it, and at measurements of a compression it becomes clear that in one or several cylinders it is lower admissible, – and the question becomes serious.

Then first of all specify the nature of malfunction: wear of tsilindro-piston group, podgoraniye of facets of valves or wear of cores and guides of plugs. Technology of diagnosing is rather simple and described in all grants on repair of engines.

Then decide on repair. Here it is only necessary to take itself for the rule: from any miracle liquids to be far away. The effect in principle is possible, but the usual result – excess expenses and efforts is reached seldom. It is better to be guided by the full-fledged repair procedure at once.

To find a workshop where engines treat, today it is not difficult any more, and not only in the large cities. But here is how work, what its quality is organized there? Life shows that at all importance of experience and qualification of employees good results without the special equipment and equipment are unattainable, and in this plan the dispersion of technical armament of our stations and mechanics, alas, is high. And if told above concerned generally the motorist operator, then the further statement is addressed not so much to it how many to the mechanic, it will be a question of technology.

In cases when results of diagnostic check indicate malfunction of the valvate mechanism, the head of the block should be removed. The first action after dismantle, dismantling and the general survey – assessment of gaps between cores of valves and their directing plugs. If they are higher than maximum permissible values, valves replace with new. But when this vague measure is insufficient, it is necessary to replace also plugs too.

For a small workshop such operation presents the known difficulties: pig-iron plugs press in the aluminum case with a tightness. At the same time to avoid microcracks and smyatiya, plugs should be cooled previously in liquid nitrogen (temperature – 196 °C), and to warm up the case to 160–170 °C (there can be harmful consequences above). All this is quite difficult, labor-consuming and is often simply non-reproducible in semi-handicraft conditions. Therefore in rare workshops do not deviate from the ordered conditions that directly develops into loss of quality of landing and distortion of geometry of knot. It is corrected then, processing "in the place" saddles of valves a vertical drill or a sharoshka, and valves long and tiresomely grind in.

But today there is also other technique, extremely profitable both on labor input, and on investment of capital which at the same time guarantees high-quality results. It is reached by use of the original and almost unknown tool of the American company Neway in our practice.

With its help restoration of worn-out guides of plugs is made on the place, without vypressovka! Special knives rollers cause plastic deformation of metal, compensating wear of an internal surface of the plug, at the same time forming in it a spiral fillet which improves valve core lubricant conditions, and also serves as a peculiar labyrinth consolidation, oblegachayushchy a task to oil scraper caps.

Five knives and a set of development for finishing processing of the plug are included in the package. It is characteristic that all operations with the Nyyuey tool are conducted manually and are not connected with power supply or other energy from the outside.

Now about saddles of valves. At traditional methods of their processing directing a sharoshka or a vertical drill freely rotates in the valve plug. Mills of "Nyyuey" have a motionless axis which is densely fixed already in the restored plug by self-established broad collet "pilot". The mill is put on an axis with a precision gap of 0,5 microns that provides the minimum admission of processing. Mills of "Nyyuey" due to unique sharpening and a form of the cutting edges form on a valve saddle surface a special microrelief like "comb": extra earnings of the valve and a saddle occurs quickly and effectively, and need for grinding in disappears. Their productivity is high: any facet on a saddle of the valve turns out for 3–4 turns of the tool.

The last stage – restoration of working facets of valves. For this operation Nyyuey offers the special Gizmatik-2 tool. The valve is not movably fixed in special adaptation which is installed, in turn, in table vises. There are enough several rotations of a mill (axial giving obespechivtsya by the microelevator) to receive the ideal concentric surface of the valve. Let's notice that on its working surface, as well as when processing a saddle, the special microrelief is also formed.

Here, actually, and all. It is necessary only to wash out and grease all details, and it is possible to collect a head.

And grinding in? Let's remind once again: during the work as the Nyyuey tool in this tiresome, long and tiresome operation there is no need. After processing of couple "valve saddle" interface of both details happens on very narrow corbel, practically on the line.

It is reached small (to one degree) by a divergence of angles of processing of working surfaces of a saddle and the valve (between them the so-called interferential corner is formed). In the first seconds of operation of the engine the area of interface increases for the account a smyatiya of superficial ledges of the created microrelief on facets, and then there is a necessary 100 percent consolidation.

At the cost of set of the equipment about 400 dollars (depending on a complete set) "Nyyuey" can pay off in the first month of work, and at repair of engines of foreign cars to bring in the noticeable income.