BMW 3 Series E30

since 1983-1994 release

Repair and operation of the car

Today gear belts found "second wind". Practically all car makers equip the cars with the elastic drive. The German designers went further away. They widely apply a double gear belt (Duplex) as reliable connection of a cam-shaft with the krivoshipno-conrod mechanism.

The gear belt has a number of advantages before a chain. It it is obvious more expensively. It is much simpler to make a belt, than a chain. By and large, it is the closed tape from maslobenzostoyky rubber reinforced by a kapron cord with teeths, pirvulkanizirovanny to it. If to compare it to a chain, then comparison will appear not in favor of the last. The belt is much lighter than a chain that, naturally, cannot but affect the mass of the engine. Besides, the engine equipped with a belt, the fellow much more quietly equipped with a chain. Also "elastic band" out of an engine casing is mounted that affects time of its installation or replacement. For example, at the author of these lines on replacement of a GRM belt with the subsequent its installation on tags 25–30 minutes leave. With a chain such focus will not pass.

At the correct service and control the gear belt goes long. Domestic manufacturers, we will remind, give a guarantee for a run in 60 thousand km, foreign – and that it is more. Rover managed to postpone the time of replacement of a belt to 160 thousand.

What the correct control and service of this simple adaptation consists in? At least, than each 15–30 thousand km correctness of situation and tension of a belt has to be checked. However it does not mean that it is only necessary to remove a casing and to check, whether on the place a belt. It is the best of all to examine it, having removed from the engine. Sometimes it is difficult to notice that one of teeths overstrained. If it already occurred, then be sure that he will not stretch. Therefore, having taken off a belt, make on it a mark chalk, and further tooth behind tooth "banish" it. After installation it is also necessary to check the provision of guides and a natyazhitel. All these elements have to be on one axial, otherwise the belt will work with a distortion that will not do it good.

Important factor for work of a belt – absence on its surface of oil. Whatever was maslobenzostoyky rubber of which the belt is made, nevertheless it is not that case when "oil you do not spoil porridge". Here oil just to the detriment. Therefore it is periodically necessary to pay attention to a condition of epiploons. And if you noticed an oil leak, try to eliminate somewhat quicker it. As practice shows, stay of a belt in the oil environment cuts its resource by half, and even three times.

If to ignore this control, then consequences will not keep themselves waiting long. Through 40-50 thousand km at the expense of a belt pulling the necessary tension weakens and it begins to whip. As a result of it the heavy cam-shaft rotates not synchronously, and with lag. This asinkhroniya of operation of the motor leads to a bigger weakening of a belt. As a result there are excessive loads of teeths.

The break of several teeths in a row can lead to the fact that once the cam-shaft will remain motionless while the knee will rotate. At such moments open valves meet pistons. Result – a fiasco or a bend of the valve, its broken plugs, the broken-off cam-shaft. There are, however, also exceptions when the break is painless practically. However it is possible only on those cars in which specially on this case there are pro-points in pistons. For example, our VAZs, namely cars with VAZ-2105 engines, 1300 cubic cm, and VAZ-2108, 1500 cubic concern them see.

If the car is not equipped with such engine, the break of a belt costs the owner in the round sum connected with overhaul of the engine. Cost, for example, of a belt on BMW reaches $40. repair of the engine on the same Saab will cost $5000. For VAZ "nine" the belt can be bought for $25. And here repair of a cursor will pull for $400.