The filter is not oil or insufficient oil reasons:
1. The filter paper quality of the oil filter is poor, and the microaperture is small
2. The oil filter inner mesh plate has a small oil hole and a small oil supply
3. Just installed the filter, the air in the oil circuit is not drained
4. The car oil circuit is blocked, no oil or less oil
5. The weather in the north is cold, the temperature is low, the oil flow is poor, and it is difficult to oil
6. The use of inferior oil, glue, easy to block the filter paper, resulting in oil circuit
7. The filter without bypass valve is not oiled after use for a period of time, which may be that the filter paper has been blocked and a new filter needs to be replaced
8. There is no oil in the use of the bypass valve filter, which may be blocked by the filter paper, but the opening pressure of the bypass valve is large or it is stuck and cannot be opened