3.14.1. Knocks in the engine
If it seemed to you that at operation of the engine there were sounds which was not earlier, be immediately convinced, whether all as it should be with the engine. More often knock in the engine is connected with serious malfunctions, for diagnosing and which elimination it is necessary to assort the engine in the conditions of service or garage. However it is possible to try to define independently the knock reason to solve, go to car-care center under the own steam or on a tow.
If you have slightest doubts in independent diagnostics, get a towing cable. Serious repair of the damaged engine will be more expensive, than tower services.
Knock of radical bearings (it is listened in the most lower part of the block of cylinders) – very dangerous; stop immediately the engine, it is necessary to go to car-care center or garage on a tow. Knock of low tone, considerably amplifies under loading and at increase in frequency of rotation of a cranked shaft. Often its emergence is accompanied by oil pressure drop (the alarm lamp of emergency pressure drop of oil burns almost constantly).
Knock of shatunny bearings (it is listened in an average part of the block of cylinders) – very dangerous; immediately stop the engine, it is necessary to go to car-care center or garage on a tow. Sound rhythmical, ringing, metal, average tone. Considerably increases at increase in loading and completely vanishes at spark plug shutdown.
Knock of piston fingers (it is listened in the top part of the block of cylinders) – dangerous; without loading the engine, it is possible to reach to car-care center or garage independently. Rhythmical, a high-pitch tone with a sharp metal shade, it is audible on all power setting, amplifies at increase in loading at the engine. Completely vanishes at spark plug shutdown.
Knock of worn-out pistons and cylinders (it is listened in the same part of the engine, as knock of piston fingers) – harmless; without loading strongly the engine, it is possible to reach to car-care center or garage independently. A sound reminding knock of pottery. It is especially well audible on not heated-up engine, in process of warming up decreases or disappears.
Knock of valves (it is listened in the top part of the engine around a cover of a head of the block) – harmless; it is possible to reach to car-care center or garage independently. Metal knock against the general deaf noise. It is well listened on small and average frequency of rotation of a cranked shaft from a head of the block of cylinders over the locations of valves.
Detonation knocks are dangerous, but are, as a rule, eliminated with replacement of the sensor of a detonation or filling by qualitative fuel. Avoiding strong loading of the engine, it is possible to reach to car-care center or garage independently. The ringing metal knocks arising, as a rule, at dispersal of the car. The reason — failure of the sensor of a detonation, application of nizkooktanovy fuel, an engine overload at too early inclusion of an overgear, a considerable nagaroobrazovaniye in combustion chambers. It is necessary to apply a special additive to fuel to deposit removal on valves and combustion chambers.