Clogged oil filter will cause the following problems: 

1. The service life of the oil filter is determined by the dirt holding capacity. For example, the dirt holding capacity of a certain oil filter is 5 grams. When the impurities attached to the filter paper exceed 3 grams, the pressure of the oil passing through the oil filter will increase significantly; When the impurities attached to the filter paper exceed 4 grams, the oil flow will be greatly affected, the oil pressure will be slow, and the lubrication system will be poorly lubricated; When the impurities attached to the filter paper exceed 5 grams, it is difficult for the oil to pass through the filter paper, that is, what we commonly call the oil filter element is clogged;
2. Generally, when the dirt holding capacity of the oil filter element exceeds half, the oil filter element should be replaced. The oil filter of most car models is designed in this way. The oil filter of some models is designed to be larger and has a larger dirt holding capacity, so it can be used for a longer time. It is also possible to change the oil twice and replace the oil filter once; The oil filter of some models is designed to be very small, and the dirt holding capacity is naturally relatively small. Even if a fully synthetic oil is used, the oil and oil filter element must be replaced once 5,000 kilometers;
3. The dirt holding capacity of the oil filter is mainly determined by the amount of filter paper in it. This filter paper is a special microporous filter paper. It has a good filtering effect, good circulation, and sufficient mechanical strength, so its price is relatively high, and the main cost of the oil filter is also here. Some oil filters look exactly the same in appearance, but the content and material of the internal filter paper are completely different, and the service life is naturally very different. The price is also very different, ranging from a few dollars to dozens of dollars. It can be said that for a particularly cheap oil filter, the internal filter paper must be very small, so it is better to use less of such an oil filter;
4. Because the impurities and gums filtered by the oil filter are stored in the oil filter, it does not have a self-cleaning function. Therefore, if there are too many impurities and gums in the oil, the oil filter will become clogged due to excessive impurities over time. At this time, the bypass valve of the oil filter will open, and the oil will directly enter the lubricating oil circuit without passing through the filter, causing the oil filter to fail.