The function of the oil filter element is to filter the oil: 
1. The main function of the oil filter is to filter most of the impurities in the oil, keep the standby oil clean and prolong its normal service life. In addition, the oil filter should also have the performance of strong filtering capacity, low flow resistance, and long service life;
2. Under normal circumstances, all parts in the engine are lubricated by engine oil to achieve normal operation. However, metal scraps, dust, carbon deposits that are oxidized at high temperatures, and some water vapor generated during the operation of parts will continue to be mixed into the oil. Over time, the service life of the oil will be reduced, and it may affect the normal operation of the engine in severe cases;
3. In order to ensure the filtering effect, multi-stage filters are generally used: filter collector, coarse filter and fine filter. The filter connected in series with the main oil passage is generally a coarse filter; the filter connected in parallel with the main oil passage is generally a fine filter, with an oil flow rate of 10%-30%;

The working principle of the oil filter:
1. With the continuous accumulation of impurities on the filter paper, the passability of the filter paper continues to decrease, and the circulation resistance continues to increase, which makes the oil pressure on the outside of the filter paper continue to rise. When the oil pressure is sufficient to open the bypass valve, the oil is no longer filtered by the filter paper, but directly enters the center pipe from the bypass valve, and then enters the engine lubrication system from the oil outlet in the middle of the oil filter base plate to participate in lubrication;
2. All parts in the engine are lubricated by the engine oil to achieve normal operation, but the metal chips, dust, carbon deposits oxidized at high temperature and part of the water vapor generated during the operation of the parts will continue to be mixed into the engine oil. Over time, the service life of the oil will be reduced, and it may affect the normal operation of the engine in severe cases;
3. Therefore, the role of the oil filter is reflected at this time. Simply put, the main function of the oil filter is to filter most of the impurities in the oil, keep the standby oil clean, and extend its normal service life. In addition, the oil filter should also have the performance of strong filtering capacity, low flow resistance, and long service life.