Why should the various filters on the car be replaced regularly?

Everyone knows that cars must be maintained on a regular basis. During maintenance, the oil and oil filters, air filters, and fuel filters need to be replaced, referred to as "three filters". Everyone can understand that when changing the oil, any oil has a shelf life, and the quality of expired oil will decrease, which will reduce the protection of the engine. But those filters do not have a shelf life, why should they be replaced simultaneously? What happens if it is not replaced for a long time? Let's analyze this problem below.

Oil filter

The oil filter is called the "kidney of the engine", and its main function is to filter impurities in the oil and provide clean oil to the engine. Because the engine will produce a large amount of carbon deposits, gums, sludge, metal wear debris, etc. during operation, these impurities are mixed in the engine oil and if they are not filtered out, it will aggravate the wear of the engine. With the oil filter, leave these impurities on the filter paper of the oil filter, and the engine can get clean oil.

What if the oil filter is not replaced for a long time? There is a bypass valve in the oil filter, this valve will open when the oil filter is clogged to prevent the engine from not being lubricated by the oil. If we don't change the oil filter for a long time, the filter paper has too much impurities and the oil cannot pass through, the bypass valve will be opened and the oil will be directly supplied to the engine without filtering. The most popular way is to say that there is no oil filter. At this time, the residual carbon, gum, sludge, metal wear debris, etc. in the oil will enter the lubricating surfaces of the engine along with the flow of the oil, thereby aggravating the engine's Wear.

Therefore, the oil filter is generally replaced at the same time when the oil is changed. When we choose the oil filter, we must choose the original parts or brand parts with guaranteed quality. Many sub-factory parts and fake and inferior oil filters generally have insufficient dirt holding capacity. The filter paper will be sufficient in a short time It is blocked, and the bypass valve is opened, and the oil is not filtered from now on. If the opening pressure of the bypass valve is high, it will cause poor lubrication of the engine. Also, if you are using long-term oil, you must use a long-term oil filter to prevent the oil filter from failing earlier than the oil.

Air filter

The air filter is called "the mask of the engine", its function is to filter out the sand, impurities, etc. in the air, and provide clean air to the engine. If the unfiltered air enters the engine directly, the hard particles such as sand particles and impurities in the air will enter between the piston and the cylinder wall, aggravating the wear of the cylinder and shortening the service life of the engine.

What if the air filter is not replaced for a long time? The air filter is filtered by microporous filter paper. These micropores can pass air, but impurities cannot pass. After long-term use, these micropores will absorb a lot of impurities, resulting in a significant decrease in the passage capacity of the micropores, and a decrease in the amount of air entering the engine. The engine will be weak, unable to increase the speed, power drop, and smoke. malfunction. If it is not replaced all the time, impurities will enter the engine through the pores of the filter paper under the powerful vacuum suction of the engine, and at the same time, the pores of the filter paper will become larger and the filtering effect will deteriorate, which will result in increased engine wear.

The replacement cycle of the air filter should depend on the specific situation. If the air in the area is good and the dust content is low, it can be replaced once for 10,000 or 20,000 kilometers; if the area has a large amount of dust in the air and the air quality is poor, then at least 5,000 kilometers must be replaced. When replacing, choose a high-quality filter element with guaranteed quality. Inferior filter elements generally have larger pore diameters and poor filtration effects, so they are not recommended. In addition, there is a so-called "KN" air filter, which is an oil-absorbing air filter composed of a metal filter. Its filtering effect is not as good as that of ordinary paper air filters. It is used in ordinary private cars. Not recommended for use.

Some people may say that the air filter has been used for a long time, so I just blow it with compressed air to blow off the impurities adsorbed on it. In fact, this is not right. On the one hand, the compressed air pressure is very high, which will enlarge the pores of the filter paper; on the other hand, if the blowing method is not correct, it will seriously damage the air filter. Generally, we can blow once in the middle of the air filter replacement cycle. When blowing, the pressure of compressed air must not exceed 0.4 MPa, and blow from the reverse side to the front. It is not allowed to blow from the front to the back. For the large air filter of the truck, it is generally only allowed to blow twice, and it must be replaced the third time.

Fuel Filter

Fuel is the food of the engine, and the power of the engine is converted from fuel combustion. Fuel is divided into gasoline and diesel, and their filters are slightly different. Today we only talk about gasoline filters. The function of the gasoline filter is to filter impurities, gums, etc. in the gasoline, provide clean gasoline to the engine, and prevent "illness from entering the mouth." As fuel is inevitably mixed into some impurities during production and transportation, certain moisture will be absorbed during storage, and these impurities will seriously damage components in the fuel system. For example, the extremely precise fuel injector coupler has an accuracy of only a few microns. If impurities and gums in gasoline enter the coupler, the surface of the coupler will be scratched, which will cause the injector to drip and fail to open.

What happens if the gasoline filter is not replaced for a long time? The filtering principle of the gasoline filter is also completed by the internal microporous filter paper. If the microporous filter paper is not replaced for a long time, the microporous filter paper is full of impurities, gums, etc., which will lead to poor passability and insufficient gasoline. Supply the engine, and then there will be failures such as weak acceleration and insufficient power of the car.

Gasoline filters are divided into built-in and external. Generally, the built-in type is replaced once for about 60,000 kilometers, and the external type is replaced once for about 30,000 kilometers. If the fuel quality in the area is not good, shorten the replacement cycle.

Air conditioning filter

Another type of filter in a car is the air conditioner filter. The function of this filter is to filter the air entering the passenger compartment to prevent the occupants in the car from breathing dirty air. It is generally replaced once every 10,000 kilometers, and the cycle can be appropriately extended or shortened according to the local air quality; if it is not replaced for a long time, the air quality in the car will be poor, and the air-conditioning volume will be small. The overall air quality in China is not good, so some models use this air conditioner filter to make a fuss, claiming that their cars have the functions of filtering PM2.5, filtering viruses, etc., which are actually some gimmicks. As long as it is a qualified air conditioner filter, the filtering effect is similar.