When the loader is idling, it can hear uniform and slight exhaust sound; When running at high speed, it will sound steadily. If the sound increases, accompanied by power decline, increased fuel consumption, increased vibration and other phenomena, it can be judged as abnormal sound. In case of abnormal sound of the engine, the types and possible causes of the sound can be judged according to different technical conditions, different sounds, different working conditions and spatial positions of each cooperation, the location and sound characteristics of the sound, as well as the timing and change law of the sound.

（一）氣門敲擊聲在氣缸蓋罩部位有清脆的金屬敲擊聲，當(dāng)柴油機(jī)在中、低速變速時(shí)，敲擊聲更為明顯、清脆。出現(xiàn)有規(guī)律的“噠、噠”聲，主要是由于氣門間隙過大造成的。柴油機(jī)溫度升高或用“斷缸”方法試驗(yàn)時(shí)，響聲均不發(fā)生變化。

（1） There is a crisp metal knocking sound at the cylinder head cover. When the diesel engine changes speed at medium and low speed, the knocking sound is more obvious and crisp. Regular "Da, Da" sound is mainly caused by excessive valve clearance. When the temperature of diesel engine rises or the "cylinder breaking" method is used for test, the sound will not change.

（二）礦井裝載機(jī)的活塞銷響的主要原因是活塞銷、連桿襯套或活塞銷座孔磨損，導(dǎo)致配合間隙過大，活塞銷在運(yùn)動(dòng)中發(fā)生撞擊而發(fā)出響聲

（2） The main reason for the piston pin noise of mine loader is that the piston pin, connecting rod bushing or piston pin seat hole are worn, resulting in excessive fit clearance, and the piston pin makes a noise due to impact during movement

（三）活塞敲缸響的常見和主要的原因，是因?yàn)榛钊c氣缸壁磨損，配合間隙超過一定的限度，活塞在上下運(yùn)動(dòng)的過程中發(fā)生擺動(dòng)，敲擊氣缸壁而發(fā)出鐺鐺的響聲。

（3） The common and main reason for piston knocking is that the piston and cylinder wall are worn, and the matching clearance exceeds a certain limit. The piston swings in the process of up and down movement, knocking on the cylinder wall and making a clang sound.

（四）連桿軸承響的主要原因，是軸頸與軸承磨損，軸承合金層燒壞、脫落、軸承蓋（瓦蓋）松動(dòng)，軸承轉(zhuǎn)動(dòng)（軸瓦走外圓），做功的瞬間相互撞擊而發(fā)響

（4） The main causes of the connecting rod bearing sound are the wear of the journal and bearing, the burning and falling off of the bearing alloy layer, the loosening of the bearing cover (pad cover), the rotation of the bearing (the bearing pad goes to the outer circle), and the sound is caused by the instantaneous impact of work

（五）曲軸軸承響的原因與連桿軸承響相同，其特點(diǎn)為：響聲較敲缸、活塞銷和連桿軸承響沉悶。

（5） The reason for the crankshaft bearing noise is the same as that of the connecting rod bearing. Its characteristics are: the noise is more dull than that of knocking the cylinder, piston pin and connecting rod bearing.

（六）凸輪軸軸承響常見和主要的原因，是凸輪軸與軸承（軸套）磨損，配合間隙過大；軸承合金層燒壞、脫落或軸承外徑與座孔軸承“走外圓”。

（6） The common and main cause of camshaft bearing noise is the wear of camshaft and bearing (shaft sleeve) and excessive fit clearance; The bearing alloy layer is burnt out or falls off, or the outer diameter of the bearing and the seat hole "go to the outer circle".