In order to optimize the processing technology, in order to optimize the processing technology, there are some machining holes in the lubricating oil channel, water jacket (Road) and so on. In the working process of the engine, these machining holes must be in a closed state in order to ensure the normal work of the lubrication system and the cooling system. In most cases, the cylinder manufacturer will end the machining holes in a certain way at the end of the processing process, but sometimes there will be no plugging in the processing hole. If the repairman does not pay attention, it will open the hole in the block and cause problems in the corresponding system. . Here are two cases of low oil pressure on the engine when working holes were not blocked on the lube.