I caught (knocked) engine: what it is?
During operation, the main indicators of the good condition of the internal combustion engine is the sound of the engine, stability of the unit operation in different modes, no problems with startup, etc.. As for extraneous noise during engine operation, the appearance of different sounds may indicate the occurrence of certain faults. These faults should be divided into two groups. The first includes breakdowns, which do not pose a great threat to the main components and units of the internal combustion engine. The second gets sounds, which directly or indirectly indicate a high probability of serious engine failure, which leads to the need for major repairs or replacement of the existing power plant with a new engine, b / to the unit from the "donor", contract engine, etc..
We also recommend reading the article about it, what is a contract engine. In this article you will learn about the advantages and disadvantages of units of this type, and also find answers to questions, where and how to choose, and then buy a contract motor.
There can be many reasons for knocking the engine in the bonnet space, from the wear of the actuators or rollers of the attachments and ending with the knock of the valves, hydrocompensators and other elements of timing. As for the question, when knocking inside the engine itself, it can be pistons, crankshaft, connecting rods and other components of the CHP. Let's take a closer look at the possible causes of engine knocking.
Why the engine "knocked": possible reasons
Let's start with the definition. Drivers often talk, that the engine knocked or knocked. What does "caught the engine" really mean? Under such wording of malfunction, usually, Professionals and experienced amateurs understand the change in the sound of the internal combustion engine precisely because of problems in the field of CNG, KShM and GRM, which means the need for major repairs.
Note, not every driver can accurately determine such a knock. In such cases, inexperienced car owners say, that the engine knocked, the definition is used in cases of any extraneous sounds of shock or other nature during the operation of the internal combustion engine. In other words, it is most correct to apply the definition of "engine caught" just then, when knocking inside the engine, and not in attachments or in the area of attachment pulleys. The definition was sorted out, now let's move on to the reasons themselves.
Internal combustion engine, regardless, what type of unit is under the hood (petrol, diesel, hybrid or rotary) consists of many loaded nodes. Mechanisms and systems inside the engine (KSHM, Timing, etc.) form so-called friction pairs. A working motor should run quietly, which means the integrity and normal interaction of all parts with each other, as well as the efficient operation of the lubrication system.
The appearance of metal knocks (hit metal against metal, rattle or squeak) is a reason for immediate cessation of operation and in-depth diagnostics of the engine to identify the causes as soon as possible. You should also pay attention to the nature of the knocks, taking into account individual characteristics:
- the engine knocks only on cold and / or hot;
- the sound appears at high or low speeds;
- knocking in the engine is manifested with a certain frequency
- the motor knocks constantly, with equal force, loud or deaf;
- knocks in the engine progress (intensified) or remain at the same level;
Let's add, that the increase in the overall noise level may occur by itself, that is, it does not have to be a malfunction. This is true for engines with solid mileage, which are already worn out and cannot work as quietly, as new units. A knock on the engine can also be caused by overheating of the engine, use of incorrectly selected or poor quality (counterfeit) engine oil, of long operation of the engine at considerable excess of the recommended interval of service replacement of lubricant and the oil filter. Example, riding on oil without replacing more 20-25 thousand. Km. instead of the recommended ones 15 thousand. km.
The engine is knocking: dangerous and not very
Given the above, the knock can be divided into:
- loud knock of the engine, which means the need to stop the operation of the engine;
- weak knock of the engine, which occurs as a result of natural wear of individual components or for other reasons;
Usually the engine starts not knocking very much or periodically knocking as a result of inconsistency of engine oil of this type of engine on certain characteristics or after aging of lubricant. The reason is obvious, engine parts are lubricated less efficiently, as a result there is an increase in noise. You can also hear the knock of compensators or poorly adjusted valves. Compensators start knocking like bad oil, and as a result of own wear. pay attention, on motors without hydrocompensators to regulate the valve optimally not later than through each 20-25 thousand. Km. mileage.
In the list of possible causes of knocking is the timing belt. To be precise, we are talking about tension or guide rollers. It is not the engine itself that starts knocking, and the bearing in the drive device on motors with a belt to actuate the timing mechanism. As for the units, having a timing chain, attention should be paid to the state of the circuit itself, chain tensioner, etc..
Knocking can also be caused by problems igniting the mixture, which is a detonation, hot ignition, and also received on gasoline engines the name of dieseling. Gradual production of a camshaft leads to increase of superfluous noise on the worn out engines, crankshaft, valve mechanism, etc.. In such situations, the engine may knock, but it is still possible to work properly for a long time. It is often possible to eliminate the causes without a global overhaul of the internal combustion engine. In the worst case, it is necessary to make overhaul of cylinder head, change drive rollers, chain, etc.. Now let's talk about those cases, when there is a knock on the engine, there are serious problems.
Let's start with the most common symptoms. In the list of the most frequent and dangerous knocks of the engine the following are noted:
- knock of pistons;
- the knock of the connecting rods;
- crankshaft knock;
We also recommend reading a separate article about knocking the engine, in which the possible reasons are considered in detail, as well as signs, which can more accurately determine the cause of the nature and characteristics of the sound of a knocking motor.
Usually malfunctions of this kind are accompanied by a distinct metallic sound, which is manifested with a certain constancy or increases with increasing speed. Crankshaft knocking can also occur after unqualified engine repairs, as the bolts at the point of attachment of the connecting rod head to the crankshaft may not be tightened enough. Knocking is also common ??such, when the piston starts knocking. Piston knock is manifested in the cold, with warming may weaken.
One of the most dangerous sounds is considered to be the knock of the crankshaft. Without going into details, the crankshaft is fixed by means of so-called inserts (radical and basic). If the crankshaft insert turns, that is, tears off the seat, the part begins to rotate together with the crankshaft, resulting in strong metal impacts or engine jamming.
Problems with the support liner, which limits the movement of the shaft in the horizontal plane, lead to a strong cloning beat. Faults of this kind cause the actual destruction of the internal combustion engine, since the broken bed was cloned, the shaft itself and other elements of the engine. If distinct metallic sounds are heard in the engine while the unit is running, then there is a high probability, that caught the crankshaft. Remember, in this case, operation must be stopped immediately, since the engine can jam. The so-called "wedge" of the engine is the most serious malfunction, after which in some cases it is advisable not to repair, and completely change the engine. If the engine is still spinning, then there is a chance to get rid of grinding / replacement of the crankshaft and replacement of liners.
As a result, I would like to note once again, that not only the engine can knock. Example, a broken or defective flywheel crown will mean, that when trying to start the engine with a starter, the driver will hear a loud metal grind. If the motor is chain, noticeably makes noise and taps the stretched timing chain. The water pump can make extraneous sounds (pump), air conditioning compressor, GUR, etc..
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