Одним из ключевых механизмов в двигателе внутреннего сгорания является привод газораспределения. Он необходим для вращения распределительного вала и своевременного открывания клапанов в цилиндрах. Каждому автовладельцу не помешает более подробно узнать о том, what is the timing belt, и что может произойти в случае его обрыва.

Content

• 1 What is a belt
• 2 Does your car have a timing belt
• 3 How long does the timing belt serve?
• 4 Why timing belt breaks
• 5 What to expect after the cliff
• 6 Symptoms

What is a belt

The appearance of the timing belt

To improve the transmission of torque used belts with a toothed inner surface. The use of products with a flat surface is impossible, as slippage occurs, as a result of which the timing mechanism starts to work incorrectly - the intake and exhaust cycles are lost, and the result is the impossibility of engine operation. The essence of the belt drive is the synchronization of the piston and valve system. For the normal functioning of the internal combustion engine, it is extremely important that the intake of fuel and the release of exhaust gases take place at a certain position of the piston in the cylinder. Therefore, a flexible V-ribbed belt is used to synchronize the operation of the motor. That's what a timing belt in a modern car.

Does your car have a timing belt

Almost all the cars that were made a decade and a half ago, it was equipped with a belt. Today, the trend of automakers is a bit twofold - they continue to install belts on low-cost cars, as this reduces their cost. But the more expensive models have a chain in their design - it is considered more reliable and durable.

To determine whether there is a timing belt in the engine of your car, simply open the owner's manual or look under the hood. Usually the timing mechanism is located on the left side of the motor (facing the car), covered with a plastic cover. The fact is that the lubrication belt is not needed and it is located outside the engine block. But the chain needs oil for normal operation, it is enclosed under a massive metal cover, under which lubricant penetrates from the engine tray. If in doubt what type of drive in your car, look at the forums that are devoted to your model.

Modern cars are increasingly equipped with a timing chain drive.

How long does the timing belt serve?

There is no final answer to this question, since the resource of an element is influenced by many factors, among which the first place is taken by quality. If you use the original belt, then it can without any difficulties serve exactly the period that is declared by the automaker. Therefore, it is necessary to adhere to the replacement time, which is recommended by the manufacturer, and when the timing belt is replaced, it is time, do not over tighten it. But often in stores people buy universal components that can be installed on dozens of models from different manufacturers. It is necessary to be afraid of such sets, since there is practically no confidence in them. One thing, if you buy universal wipers, and quite another - the same universal engine elements.

See also: What does contract engine mean

Most of the cars need to replace the timing belt and pulley after reaching a distance of 60 thousand km. But there are small nuances. If the vehicle has been in use for more than five years, it is necessary to replace the components with 10 thousand km earlier. So you protect yourself from a broken belt due to excessive wear. A similar requirement is imposed on machines that were produced 10-20 years ago. The older the engine, the more attention is paid to it.

Change the timing belt is usually necessary every 50-60 thousand kilometers of a car

Why is timing belt torn

A broken belt can happen at any time. And the reasons for this trouble abound. Consider the main ones:

1. Excessive wear, late replacement or poor quality of the material from which the belt is made.
2. Lubrication of the surface of the belt, as well as the ingress of dust, dirt.
3. Violation of the pump, the formation of a backlash in its bearing or a complete jamming.
4. Seizure of the camshaft, crankshaft or timing pulley.
5. There are foreign objects under the protective case - stones, slivers, etc.

What to expect after the cliff

А теперь о самом печальном – о последствиях обрыва. Стоит заметить, что он может пройти безболезненно, а может и навредить ГБЦ. Все зависит от того, какой двигатель, какой тип поршней. Практически всегда timing belt break безболезненно проходит на двигателях более простых конструкций. Чем сложнее устройство ДВС, тем плачевнее последствия. В некоторых моделях двигателей, когда поршень находится в ВМТ, тарелка клапана не достает до его поверхности. В других использовано небольшое ухищрение – сделаны небольшие выемки в поршне, чтобы не допустить соприкосновения с клапаном. Но что касается большинства 16-клапанных моторов, то они не защищены от обрыва. И когда он происходит, то загибание клапанов неизбежно.

If the belt is not replaced in time, either partial destruction of the belt or complete breakage may occur.

And the essence is quite simple - the belt breaks, the camshafts remain exactly in the position they were in during the break. But the crankshaft continues to rotate. As a result, the pistons repeatedly hit the valves. Of course, even the strongest metal can not cope with such a load. As a result, all the valves bend. A less “traumatic” result is a broken belt at idle. In this case, only a few valves are damaged. But the next steps remain the same - you will have to repair the cylinder head. And even if the damage is present on 3 or 4, it is better to change everything at once.

See also: Why the engine overheats

Sometimes there is a destruction of the pistons, guide bushings, the appearance of cracks on the head of the block. Fortunately, this happens quite rarely - at very high speeds. To repair the engine is very expensive, especially if it is of foreign manufacture. It will be easier to buy a contract. If you believe the statistics, the engines DOHC (mainly on Japanese cars) are very poorly tolerated by a broken belt. But no comparison does not come with this all open belt on diesel engines. Due to the peculiarities of their design, the entire timing distribution mechanism and the piston group - connecting rods, bearings and pushers, fail. And if this happens at high speeds, the overhaul of the cylinder head is inevitable.

Symptoms

1. The presence of black smoke from the exhaust pipe.
2. Difficult engine start.
3. The appearance of engine vibrations.
4. Extraneous noise.

The most common consequence of a broken timing belt is the folding of the valves.

If at least one of these faults is present, then immediately inspect the timing belt. Of course, competent mechanics at the service station will inspect more efficiently, and they will be able to identify all the problems in the engine using diagnostic equipment. But a visual inspection of the belt can be easily done by yourself.

But these are only minor signs of a broken timing belt. There are symptoms that directly indicate the poor condition of the belt. We'll have to work a little to figure them out. Despite this, all the work is quite a power to perform a person who knows how to use at least wrenches. First you need to remove the protection from the timing gear - you need to unscrew 3-4 bolts. Now you see the belt. It also needs to be inspected, check the tension, the presence of cracks and damage. Look, whether it is displaced and whether there are no damaged teeth.

Also on the belt should not be dirt, antifreeze or oil - this is a prerequisite. If there is a fluid leak, look for and fix it. If the belt gets fluid or dirt is excessive wear, perhaps even slipping. Yes, do not be surprised, the belt can jump on a shaft for a couple of teeth, which will immediately affect the operation of the engine. The tensioning roller often wears out - it can periodically wedge, because of which the belt will rub against its surface, gradually rubbing off.

Проверяют натяжение ремня ГРМ в самом длинном его участке. Если натяжение слишком сильное, то ослабьте, соответственно, при недостаточном — подтяните. Помните, чем слабее натяжение, тем выше вероятность обрыва. Теперь вы знаете, чем грозит timing belt break, поэтому старайтесь выполнять профилактические работы вовремя.