Turned the insert: possible causes, description and features of the solution of the problem

Often in numerous forums devoted to automotive topics, you can read the topic of knocking on the engine or on the cranked liners. This is an emergency situation in the ICE. When they say that the liner is turned on, it means that the plain bearings on the crankshaft and on the connecting rods ripped out of the seat and they became useless. This is a serious breakdown, which happens quite often. Motorists see the cause in low-quality engine oils from an unknown manufacturer.

But the reasons are much larger, and they are not directly related to lubrication and its quality. As proof of this, there are many examples where the root inserts fail if the engine is flooded with branded original oil. Or on the contrary - bearings work not one hundred thousand kilometers on oils of average quality. Let's figure out why crankshaft crankshaft rotates, what factors influence this and what is the main reason for this phenomenon.

Connecting rod - what is it?

In the engine there is one very highly loaded part. This is the crankshaft. The element is not installed on traditional bearings. Because of the design features, sliding bearings are used . The design of these same parts can be different. But the constant improvement of engines has led to the fact that now a sheet of steel, coated with a special antifriction layer, is used. This is the connecting rod. These elements are installed in special places - beds. The inserts are fixed. The need to fix these parts is due to the fact that they have holes for the movement of oil. They must necessarily match the same in bed. Also, by fixing, friction is provided on special surfaces intended for this purpose. The connecting rod is a kind of protective element, due to which the service life of the crankshaft is greatly extended.

The difference between the root and connecting rod inserts

It is necessary to know that there are two types of liners. They are conrod and indigenous. The first are between the connecting rod and the crankshaft neck. The root element is similar to the first in its function. However, it is located where the crankshaft runs in the engine casing. The inserts are different in size. Dimensions depend on the type of engine for which a particular part is made. There are also special repair inserts. They differ from the original new ones installed in the engine. Repair inserts differ only in marks, multiples of 0.25 mm. So, their dimensions are approximately the same - 0.25 mm, 0.5 mm, 0.75 mm, 1 mm.

Causes of cranking

So, the crankshaft is a part that operates under harsh conditions, and it has to withstand enormous loads under extreme temperatures. To ensure that the mechanism is reliably supported on the axis and could ensure the correct operation of the entire crank mechanism, liners are needed. Cervical shafts work as an inner cage. Inserts - as an external. In the engine block there are channels for supplying lubrication under pressure. Due to the oil film, which envelops the liners, the crankshaft can rotate. Why are car owners faced with situations when the engine cranked the crankshaft inserts? There are several possible reasons. Let's consider them below.

Mechanical wear

The first reason for the replacement of the crankshaft and crank liners during the engine repair is production. The parts are worn due to mechanical loads. Many try to save the liners, but this is useless. Physics is involved here, and physical processes can not work in another way. Wear is inevitable. Antifriction layer on the liner is erased with time. This leads to the free running of the crankshaft. Backlash appears. As a result, the oil pressure decreases, and it is quite significant. On most engines, which are highly reliable, if you checked the liner, this indicates their wear and tear.

Cranking crankshaft connecting rods

This is also one of the most popular malfunctions. A lot of car owners faced this problem. But not everyone knows about the reasons. Let's see what happens to the element. The conrod insert is thin enough. It is installed in a special seat. The outer walls on the semi-rings have special protrusions, which are still in the unrolled and undeveloped engine abut the front of the cylinder block. At some point, the seat simply can not hold the connecting rod. As a result, a typical situation - turned the liner. The plate not only turns, but also sticks to the crankshaft neck. In this case, the motor stalls and does not start again.

Causes of damage to connecting rod inserts

Specialists in the repair of internal combustion engines see several reasons why the plain bearings rotate. Often this is due to excessively thick oil, which gets the particles of metal. Grease with chips has an abrasive effect on the liners. Often there is a complete lack of oil. Especially this affects cars with worn oil-lubricated rings. Part of the grease just goes "into the pipe." As a result, the liner was turned and the engine was sent for repair. The bearing caps may not be sufficiently tightened. And, finally, one more reason. It's too liquid butter. Especially such products are harmful for motors that work under high loads.

Faulty interference

If checked liners, the reasons can be in this. In the production cars assembled at the plant by qualified specialists, this will not happen. But if the motor has already been repaired, then, most likely, the selection of the liners was not carried out correctly and the interference was disturbed. When the motor is running, the inserts experience an increased friction torque. This moment tends to crank the liner. And because of the reduced effort that holds the part in place, the risk of cranking increases at times. Under the influence of an uneven load, a weak landing of the friction bearing causes the liner to vibrate. Also, the lubricating film is broken. As a result, the part turns, and the restraint is unable to prevent it.

How to identify a breakdown

When cranking the main bearings, the crankshaft and the cylinder block immediately fail . In the case of cranking the crankshaft bearings, the connecting rod itself, the rotor, and the cylinder block will fail. As a result, the car owner can be helped only by overhauling the engine. This breakdown can be determined. There are some signs of cranked liners. One of them is a characteristic metallic knock on the entire motor. It does not stop even at idle, and with increasing load, it knocks even more intensively. Another sign is the low oil pressure. If the engine is cold, then there may not be any sounds. If the situation is desperate, the engine stalls, and it can only be revitalized by repair.

Repair and consequences

A typical situation - turned the liners. What to do? Solve the problem in different ways, depending on the nature of the damage. In some cases, you can do by replacing the liners with grinding the crankshaft. In difficult situations, repairs will be much more expensive. If the crank liner is turned off, then in modern engines this is not a serious problem. But this does not apply to the root. Often the situation happens that the damaged insert simply changes, and the motor works further. Specialists do not recommend this approach. The resource of the crankshaft pair of the crankshaft thus restored can be greatly reduced. A much more acceptable option is the replacement of the connecting rod with which the problem occurred. Also, if checked liners (VAZ-2172 including), the lock on the connecting rod also necessarily breaks. It will be more optimal to bore the crankshaft to the next repair size and perform a complete replacement of the liners and connecting rods. Grinding the shaft after turning is mandatory. Scuffs are formed on the neck of the mechanism. This is the only way to achieve the desired state of the surface and the engine will work correctly.

What in the end

If something is pounding in the engine, it is a signal to stop the car immediately. Do not start the engine. Most likely, inside the engine rolled liners. Repair of this breakdown can be quite expensive. It should be taken into account that the temperature of the engine's operation affects the resource of the elements. Do not overheat the engine. As for the oil, it is safest to use those products that fully comply with the requirements and tolerances of the manufacturer.

Conclusion

So, we have found out, for what reasons occurs проворачивание loose leaves of a cranked shaft. To prevent damage, do not hold the engine for a long time at high speed, change the oil, filters in time, and observe the temperature conditions of the motor.