The timing belt tore: consequences and what to do next?

Another 20 years ago, almost all machines were equipped with a chain drive timing. The use of timing belts at that time caused many motorists bewilderment. And no one could have thought that in a few years, it would be such a design to be used on all modern cars. Manufacturers explain this by the fact that the belt, unlike the chain, is less noisy, has a simpler design and a small mass. However, nothing lasts forever. What should I do if the timing belt is torn? About this and not only - later in our article.

Differences from the chain drive

During operation, the chain drive is practically not worn. It serves as much as the engine itself. Yes, it's noisier, sometimes stretched, however, unlike a belt, it never slips and breaks. Do not pull the chain. In the case of a belt, it must be periodically tightened. And improper stretching can provoke skewing on the teeth. Because of this, the motor will work incorrectly, and the resource of the element is significantly reduced.

Does the valves bend?

Among motorists there is an opinion that if the timing belt "Renault" tore, immediately the valves are bending. This is partly true. But not always. Everything depends on the complexity of the engine design. If it's a "shesnar", there will definitely be a bend in the valves. Cars that have 2 valves per cylinder (inlet and outlet, respectively) are considered more reliable in this regard. But again there are exceptions (take, for example, the Soviet "eight", a 1.3-liter carburetor). In the case of the chain, things are much simpler. It begins to ring strongly. And this noise can last long enough - one, two, three thousand kilometers. Until the car owner gets tired of this sound and he does not come to the conclusion that something is wrong here. The chain, unlike the belt, is very "tenacious" in this regard.

What does this lead to?

If you have torn the timing belt, the consequences may be different. As we said earlier, it all depends on the design of the power unit. Here you can follow the principle "the simpler the motor, the more reliable it is". When the valve in the TDC position does not reach the bottom of the piston, nothing will happen. In this case, if the timing belt is torn, you can only write in the expense item the purchase of a new product. All valves remain intact, without damaging the geometry of the rod. But not always a belt break occurs with such an easy descent. If your car uses 2 intake and exhaust valves per cylinder (and this is most cars under the 2000s), it is more likely that they will be bent. The use of this design of the timing is aimed at increasing the power. However, if the timing belt is torn, the consequences will be very sad. In this case, the camshafts (of which two) stop in the position at which the fault occurred. The flywheel, untwisted by inertia, rotates the crankshaft, because of which the rod collides with the piston. If the failure occurred at idle and on neutral, deformation of 2-3 elements will occur. If the timing belt (16 valves) is torn on the move (and at high speed, which happens in 90 percent of cases), all the elements are bent, without exception. In order to replace them, the cylinder head must be dismantled. But even if there was a bend of several elements, experts recommend changing the whole valve assembly. Also at the speed deform guide bushings. As a result, replacement or expensive repair of the cylinder block is required. If the speed and speed are too high, this is enough to deform the piston in contact with the valve. Repair it does not make sense - just a replacement.

Which motors are the most unreliable at breakage?

According to statistics, DOHC engines, as well as units from Japanese manufacturers ("Nissan", "Toyota", "Subaru") are highly prone to deformation and damage. The simplest and, accordingly, reliable are eight-valve engines with one camshaft (SOHC). They are installed on Nexia, Lanos and Lacetti.

Diesel

Whatever horror stories they tell about eight- and sixteen-valve gasoline engines, the most serious consequences still have diesel engines. Due to the more complicated design, the valves in the TDC position almost do not have a stroke. Therefore, if the timing belt is torn in the diesel engine, a whole series of nodes will deform. These are camshafts with a bearing, connecting rods (as shown in the photo above) and pushers. Also, the cylinder block is to be replaced.

Causes

There are many factors that cause a clipping:

• Contact with rubber coating of oil and dirt. To prevent this from happening, this assembly is carefully closed with a plastic casing, which is bolted on both sides. When the element is broken or replaced, this casing is often deformed, because of which foreign objects can re-enter the surface of the mechanism.
• Natural wear of the element or factory marriage.
• Wedge of the water pump, or in the common people "pump". It is closely interrelated with the work of this mechanism.
• Wedge of a tension roller, distributive or crankshaft. To cause a breakdown of the last two is very difficult, which is not to say about a pump or roller.

Replacement

If the timing belt is torn (VAZ is a foreign car - it does not matter), the first step is to install a new element. There are two reasons for the coming replacement:

• Natural wear. Manufacturers recommend replacing the element at least once every 80 thousand kilometers. However, it is not uncommon for a belt to "take care" of 150-200 thousand without deformations and whistles. But this does not mean that you can postpone the replacement for an indefinite period. This is fraught with expensive repairs.
• Mechanical damage. The belt structure can be damaged due to gross installation errors. This is a mismatch of labels, insufficient or excessive stretching of the element. Also, the belt tears (more often just flies) with an active ride "to cut off", which is accompanied by severe braking. If the machine is "proschivana" with a cutoff offset, the probability of belt breakage is high. Therefore, it is not necessary to often operate the car in the mode of hard loads.

For prolonged use it is important to pay attention to the degree of tension of the element, and if necessary, tighten it. The presence of various tears and cracks on its surface is unacceptable. By the way, an unhandled belt can fly off the marks. In this case, the take-off between the point on the camshaft housing and its sprocket will be more than one centimeter.

Prevention

To suddenly not tear the timing belt (8 valves), you need to monitor its external state and listen to the engine. If you have any doubts, pay attention to the gas distribution mechanism. Remember that replacing the belt is much easier and cheaper than repairing the engine. If he publishes a characteristic squeak or sags with the engine off, this is the first sign of his replacement. Some drivers believe that it is so "accustomed". This is a lie - the belt should work properly from the first seconds of starting the engine. Do not often pull it - the cord has the property of stretching, thereby losing strength. Because of this, the belt bursts or flies off the marks. If frequent indulgences, most likely, you installed a defective part. To avoid wedges of shafts and pumps, do not overheat the motor and try not to use it in a hard sport mode.

Cost of work

If the timing belt is torn (2112 including) without bending the valves, the cost of replacing it will be about 500 rubles. But with certain skills, you can do it yourself. Thus, the budget of the breakdown will not be more than a thousand rubles. Together with this it is recommended to check the condition of the impeller of the pump and tension roller - they should rotate smoothly, without sounds and backlash. In the event that a wedge has occurred and replacement of valves and repair of the cylinder block is required, the cost of work can reach 40-50 thousand rubles. If it's an old foreign car, it's easier to install a contract engine from dismantling - in some cases it's really cheaper than repairing an old one. Well, in order to prevent such a situation, follow the stretch of the element and its external state, and most importantly - observe the frequency of replacement in 60-80 thousand kilometers. Even if after this period the belt is not a danger (without deformations and extraneous sounds), it will not be superfluous to reinsure by installing a new element in its place.

So, we found out what to do if the timing belt was torn.