Signs of timing belt failure

Signs of timing belt failure

It is not a secret that timely maintenance of a car, keeping to the schedule, prescribed in the instruction manual is the key to faithful service. However, is everyone faithfully following the rules? Meanwhile, the failure even of insignificant, at first sight detail can cause serious damages. Thus, motorists often do not pay attention to the importance of regular replacement of a timing belt. What does ignoring the signs of timing belt failure lead to, what is the importance of the part and what is it for? If the car is very old or badly damaged due to an accident, there is no point in spending money to buy a new timing belt. In this situation, it makes sense to recycle the machine:

What is a timing belt and what is it for?

The acronym timing belt stands for timing mechanism. It is a complex element, whose task is the uninterrupted supply of fuel mixture into the cylinders and the removal of exhaust gases from them.

To do this, the mechanism performs the opening and closing of the intake and exhaust valves, which are part of the structure of the cylinders, in strict sequence. Synchronization of the engine crankshaft and camshaft torque is provided by the timing belt. It is also responsible for the operation of the water pump.

The belt replaces the noisier chain used in earlier versions of the engine. It is made of reinforced rubber with teeth. It consists of three layers – fiberglass filaments, a nylon layer, a rubber layer which gives the structure elasticity and performs a protective function.

Even such a strong structure in the process of operation loses its properties, deforms, covered with cracks, stretching, tearing.

What is the risk of malfunction

Engine operation is a continuous movement of pistons. On the intake, the piston moves downward, and on the exhaust, it moves upward. When it is at the top, the valves close. When the belt breaks, the camshaft stops and the crankshaft continues to rotate due to inertia, the pistons and valves are struck. The result is deformation of the valves.

The damage is more severe the higher the rpm. In addition to bent valves, damage to the cylinder head and pistons is possible.

In diesel engines, the consequences are even more serious, which is due to the peculiarities of the design. As a result, the valves, camshaft bearings, shaft, cylinder head and pistons get deformed.

Breakdowns of this kind require a serious expensive repair or complete replacement of parts.

Causes of timing belt failure

Most often, the cause of failure is untimely replacement, breaks come as a result of wear and tear of the part.

Improper operation of mechanisms, with which the belt interacts, can also be the cause of failure. Wear of the tensioner, crank mechanism, camshaft, rollers, valves and pistons, camshaft and crankshaft pins lead to breakage.

A common cause is the ingress of technical fluids, oil, dirt.

Often a low-quality belt purchased from unknown manufacturers does not last long. The same applies to the parts, in interaction with which it is located.

Signs of timing belt failure

Signs indicative of failure:

Cracks, visible dirt, chips, cuts, poor tension, runout.

Black exhaust smoke. Incomplete combustion of the mixture results in fuel entering the exhaust system.

Increase in engine operating temperature. The increase is due to a shift in timing, which occurs when the belt is stretched.

Problems with the ignition system when starting, irregular running, and missing detonation may be the result of belt wear, in which the teeth “slip”.

Belt stretching may be the reason of increased fuel consumption, power decrease.

Extraneous noises.

At occurrence of the listed signs it is necessary to apply to car service as soon as possible.

How often should the belt be changed?

Timely replacement will help to avoid expensive repair. In eight-valve engines, the service life is 50 thousand kilometers of mileage, in sixteen-valve engines – 40 thousand.

Check the tension of the part, its condition, should be checked after 25 thousand kilometers.

It is important to take into account the recommendations of the car manufacturer, following the accepted norms of maintenance.

In addition, the service life depends on the operating conditions. In conditions of high or low air temperature the period is reduced by 10-15%.

Purchasing a non-original belt, remember that such a part is less reliable. In this case, you must replace it twice as often.

When buying a used car, don’t tempt fate – replace the part as soon as possible.



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