Compared with the gasoline engine, diesel engine abnormal sound diagnosis is more difficult to grasp, this is decided by the structure characteristics and working characteristics of the diesel engine, such as compression ratio, thermal load, work is relatively rough, big noise, broken oil cannot instantly, and even some diesel oil at the opening of the position of the people not easy to close, to the diagnosis of abnormal noise also brings inconvenience. However, the abnormal sound of the diesel engine has its specific rules, as long as the analysis and comparison, look at the phenomenon of grasping the essence, it is possible to find out its regularity.
Connecting rod bearing abnormal sound
North Ben V3 fittings connecting rod bearing characteristics is when the speed and load increases, the sound also increases, when suddenly accelerated, continuous issued “Dangdang” sound is particularly obvious, but the sound does not change with temperature.
The reason
The connecting rod bearing and the shaft neck wear is serious, or the bearing cap bolt is loose, has destroyed the original fit clearance, when the engine is working by the strong pressure to produce the sound.
The working time of the engine is too long, the working temperature of the bearing is too high and the alloy is ablated.
North Run V3 fittings connecting rod bearing and the neck of the clearance is too small, the oil is difficult to enter the friction surface, or oil is not easy to form oil film, resulting in shaft neck and bearing dry friction or semi dry friction and burning the bearing.
The crankpin lost round.
The diagnosis and treatment methods
First look at the oil pressure gauge, if the pressure is too low, and accompanied by a “dangdang……” Sound should be further examined.
The oil cap is opened, a stethoscope, can be inserted into the stethoscope plus oil inside the mouth, can hear the knocking sound serious, then heard near the engine. When the throttle suddenly increased, the sound is more prominent.
The engine speed is slightly improved, gross area to avoid idle work, by cylinder oil break off the oil after listening, if the sound is reduced, then quickly supply the moment again issued “when” sound, the cylinder connecting rod bearing ring.
The car run on the way, if beiben V3 accessories sound connecting rod bearing is not obvious, and the broken oil after sound disappeared, and no large driving gradient, first off the oil on the cylinder sound, when traveling to repair after the repair. Special attention should be paid during this period:
A) travel distance can not be too long.
B, the throttle should be kept small and medium load, not too large, so as not to pose a threat to other cylinders.
When the bearing noise is obvious, should be in place to repair, can not be forced to travel, to avoid further damage.