When a part of the diesel engine is in trouble, it is often accompanied by abnormal noise. Diesel engine in the running state, the “abnormal sound” diverse, complex, difficult to distinguish, to the mechanical maintenance personnel often bring a lot of trouble, thereby extending the maintenance time. But as long as the normal maintenance process, pay attention to summing up grasp its regularity, can identify the noise due to wear and the gap by increasing: small parts such as the impact of the tone, high, weak, crisp, sharp and short; large parts impact, is low in pitch; small parts and parts the impact of the sound, like the small iron hammer drill; bearing and shaft collision, the sound low dull dumb. Several common abnormal sound features and identification methods are as follows.
When the engine suddenly changed when the load in Baotou Benz accessories (near the crankcase cylinder to the lower part of the central range) can clearly hear a short “empty, empty, empty blunt and dumb percussion sound, and change sharply with increasing load or speed of sound increases, open the oil cap can be heard more clearly, no load is not obvious. This is due to the excessive wear of the connecting rod and the connecting rod and crankshaft connecting rod journal clearance is too large; if the diesel engine cylinder off oil, if the abnormal sound immediately disappear, it is the cylinder connecting rod ring.
When the diesel engine has a heavy and continuous knock in the lower part of the crankcase, low audible, heavy load is more obvious at the same time, the oil pressure decreased, which is caused by the crankshaft main bearing clearance is too large; when the engine speed suddenly changed speed, on the cylinder Department issued a “clang, clang” this is the sound of the piston pin and the connecting rod bushing, or with the gap is too large due to the piston pin. If the engine is running at high speed, a “thump, thump” stuffy hammering, decreased suddenly when the accelerator is particularly serious, this is because the gap is too large due to the spindle ZWZ; in cylinder length of parts to hear the roar and dreary “empty, empty Dong Dong” knock, and open the oil port cover found the bubble (the leakage phenomenon), this is the piston and cylinder with the gap caused by too much; if in the same position slightly by the crankshaft direction to hear “crash GA, GA, GA, is Baotou Benz accessories link twisted in the swing percussion sound, after the two sound change when the rotating speed of the more obvious to hear, and easier to distinguish; along the cylinder, there were similar small hammer tap block sound, the exhaust pipe of the diesel engine (blue smoke from burning oil, accompanied by the phenomenon) with a screwdriver handle against the cylinder It is easier to hear, it can be concluded that the piston ring gap is too large or broken ring.
When the engine front side and a timing gear chamber at a rhythmic crash, crash sound, low speed sound bigger, this is the timing gear shaft and sleeve wear gap is too large due; idle operation of the engine, the timing gear chamber and the camshaft side issued no rhythm “the gala Gala” sound in low noise is more prominent, and become cluttered with a crushing sound speed, if high load noise enhancement, this is when the gear gap is too large, the tooth surface of mutual impact, or after the two gear wear sleeve disorders and percussion; vibration sound the operation of diesel engines, and it is difficult to operate, the timing gear mark installed wrong, or the balance weight is wrong, or the balance shaft bearing severe wear caused by.
In Baotou North Benz parts cylinder head office issued a “Chow, Chow, Chow” sound, accompanied by “hush, hush, hush sound of air”, when the engine will be extinguished, the sound is more obvious, this is the valve seat loose after the crash between the valve seat, and the cylinder head near the injection; is located in the upper part of the engine, hear the ringing heavy clang, clang “sound, and varies with the speed change, and the start and the combustion is not normal, this may be caused by the fall of swirl chamber; when the diesel engine hood in the valve by an outdoor like broken tiles broken” Chacha sound, or like two springs the rattle, and the middle of the exhaust pipe to the sound of an explosion, diesel engine instability, black smoke, which is caused by the valve spring break; the junction between the head and the body, if a rough and sharp” Hush, hush, hush “sound, accompanied by smoke, gas leakage phenomenon, this is being washed by the cylinder; if you hear the” hush, hush, hush “sound in the air cleaner, and the diesel engine is difficult to start, or to start after running for a period of time to touch the intake pipe feel hot hand, this is the most the valve (corrosion), coke burning, strict closure and leakage caused by the engine running in a low;” when bang, bang when “and” quack, quack “sound, the sound than the main bearing clearance is too large, the sound of many, especially sudden changes in speed greater sound, this is the fly wheel fastening the nut loosening caused by.