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 engine oil at the mouth the position is not easy to make people close to the diagnosis of abnormal sound also brought 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
Baotou beiben features parts of connecting rod bearing ring is increased when the speed and load, the noise also increases, when suddenly accelerated, continuous issued a “Dangdang” sound is obvious, but the sound does not change with temperature.
The reason
Baotou beiben parts of connecting rod bearing and shaft neck wear, or bearing cap bolt loose, damaged the gap with the original engine, strong pressure by generated noise in the work.
The working time of the engine is too long, the working temperature of the bearing is too high and the alloy is ablated.
The gap with Baotou beiben fittings connecting rod bearing and shaft neck was too small, the oil is difficult to enter the friction surface, or oil is not easy to form oil film bearing caused by dry friction or semi dry friction bearing and burning.
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 the connecting rod bearing noise 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.