First, valve foot ring is a continuous rhythmic, crisp "click" sound, idling, medium speed, the sound is clear and clear, high-speed, the sound is messy, in the valve room side to listen to, the sound is more obvious, and The sound is not affected by "fire off" and diesel engine temperature. During the inspection, the valve cover is removed first to allow the diesel engine to run at idle speed, listen to the noise of the valve and observe the effect of oil splashing. After the valve foot is found to be ringing, apply a thick gauge to check the valve clearance. If the valve clearance is larger than the standard requirement, the gap range should be readjusted. After the adjustment, the valve foot will disappear. If there is still a slight noise, the valve clearance can not be adjusted to less than the specified value, otherwise it will affect the normal power of the diesel engine. Second, the valve top rod sound is a kind of crisp and similar to the small steel ball falling on the stone plate "click" sound, the site of the ring on the axle. When the diesel engine is idling, the sound is obvious, and when the speed is above the medium speed, the sound is weakened or disappears. When inspecting, remove the valve chamber cover and hook it with the wire to adjust the screw of the valve top rod. If the sound is weakened or disappears, it indicates that the valve top rod sounds. Third, the knocking sound of the valve spring is usually caused by the valve spring being too soft or broken. Its sound is a kind of "click" sound. At the time of diagnosis, the valve chamber cover is removed and auditory and visual inspections are performed. If it is a multi-cylinder diesel engine, first find out which cylinder valve is not working properly, and then use a screwdriver to hold the valve spring. If the sound disappears, the cylinder valve spring is indicated. Too soft or broken. 4. The knocking sound of the valve seat looseness is caused by the following reasons: The material does not fit, it deforms and becomes loose after being heated, and it is loosened with improper clearance. Loose valve seat will give a kind of "click" sound, this sound is similar to the valve spring breaking sound, but it is a bit more boring than the valve spring breaking sound, if it is a multi-cylinder diesel engine, you can use the "oil off" method to determine if When the oil is cut off, the sound is not reduced. Sometimes it is even more obvious. That is, the valve seat ring is loose. When the inspection is performed, the valve chamber cover should be removed and observed. If the valve clearance is not large and the spring is not broken, it can be concluded that the valve seat ring is loose and knocked.
