How to judge the engine knock  (Dieselpartsworld) 2016-01-19   

How to judge the engine knock
Slight knock cannot be perceived by the senses, which we call it 'Knock', so when you can feel the noise and vibration generated by the engine knock, knock at this time has been a serious beyond your imagination, we called it 'Knock'. A knock after a period of time, will make the piston, cylinder head, valve, piston ring, cause serious damage.
To know what it is to know what it is, to know what is normal.
Normal combustion is the fuel mixture of gasoline engine, starting from the high pressure spark ignition. Then, the burning flame to spark as the center, spread outward, the mixture gas in the combustion chamber is ignited this is normal combustion. If before the flame has not yet arrived, the rest of the mixed gas is not ignited self ignition and the combustion knock, is not normal combustion. It is not supposed to produce knock phenomenon in normal driving, otherwise it is the engine fault.
What is the consequence of engine knock
Engine knock it will burst in the cylinder, the impact on all sides, so that the engine piston, connecting rod, crankshaft and other strong vibration, and accompanied by the sound of metal impact. Engine in normal operation, do not allow the detonation phenomenon, for a long time the detonation will lead to engine cylinders and each part of the severe wear and shorten the service life, such as damage to cylinder liner, connecting rod bearings and piston, and quickly discarded engine. Will also cause the engine power to drop the fuel consumption to increase.
Some phenomena of engine knock
Engine detonation engine has the crack of metal percussion engine cylinder sound. The engine parts temperature rise sharply, fuel consumption increases, the engine and the body can feel vibration. If the above phenomenon, the engine knock is already very serious enough to affect the life of the engine and the daily use of the engine.

Specific characteristics of engine knock:
(1) the engine in irregular "bang bang", "KaKa", "Dangdang" rapping.
(2) engine tremor.
(3) engine temperature is too high.
(4) fuel combustion is incomplete, there are black smoke in the exhaust gas.
(5) engine power down.
(6) increase in fuel consumption.
(7) in the normal running, the speed of the sudden change of reason.