If the diesel filter element is very dirty, there is definitely no way to ensure that the fuel is clean when it enters the engine cylinder and burns. After all, the gasoline added is not pure and contains impurities. Not only will it cause a serious decline in vehicle power, but there is also a certain probability that it will affect the service life of some parts and high maintenance costs. It can even block the fuel injector directly, resulting in increased fuel consumption and unstable idling. Therefore, if the gasoline filter element is found to be dirty, it needs to be replaced even if the replacement deadline has not expired. 

How to recognize whether the diesel filter element is dirty is as follows:
1. If the diesel filter element is not good, the debris in the diesel will easily block the small holes in the carburetor, making the carburetor work poorly, and the combustible mixture will become thinner;
2. The sundries in the diesel fuel enter the fuel injection pump, which easily accelerates the wear of the precision parts and reduces the pump oil pressure;
3. If the moisture and gum in the diesel enter the cylinder, it will cause the combustible mixture to burn badly and reduce the power of the engine;
4. Generally, there are three precision parts in the diesel engine supply system, which require relatively high diesel cleanliness. In order to improve filtration efficiency, diesel filters generally have two or more stages, which are divided into diesel coarse and fine filters. Installed between the diesel tank and the fuel transfer pump, the fuel transfer pump and the fuel injection pump respectively;
5. The filter element of the diesel filter has several types, such as a cylindrical felt type, a nylon cloth type, and a cotton yarn type. These filter elements have good passing performance and long service life, but they generally have disadvantages such as low filtration efficiency, complex structure, high cost, and inconvenient maintenance, and they have been gradually eliminated.