The air filter's function is to filter out suspended particles from the air entering the cylinder, reducing wear and tear on the cylinder, piston, and piston rings. Of the three mediums required for engine operation, air has the largest volume and comes from the atmosphere. If the air filter fails to effectively filter out suspended particulate matter from the air, it will, at best, accelerate the wear and tear on the cylinder, piston, and piston rings, and at worst, cause cylinder scoring and shorten the engine's lifespan.

1. Misunderstandings

1. Don't compromise on quality when purchasing

Because some maintenance personnel don't realize the importance of the air filter, they only want cheap ones instead of high-quality ones, resulting in anomalies shortly after engine installation. Especially in the current market with many counterfeit and inferior products, it is essential to compare prices, carefully select, and always adhere to the principle of quality first.

2. Arbitrary removal during use

The engine must use a scientifically proven air filter.

However, some drivers arbitrarily remove the air filter, allowing the engine to operate by directly inhaling unfiltered air. Experiments on removing truck air filters show that after removing the air filter, engine cylinder wear increases eightfold, piston wear increases threefold, and piston ring wear increases ninefold.

3. Maintenance and replacement not based on practical needs

Although the air filter's instruction manual specifies mileage or operating time as maintenance or replacement data, the maintenance and replacement cycle of the air filter is also related to environmental factors.

For vehicles frequently operating in dusty environments, the maintenance or replacement cycle of the air filter should be shortened; for vehicles operating in less dusty environments, the maintenance or replacement cycle can be appropriately extended.

In practice, many drivers and maintenance personnel mechanically follow regulations, failing to flexibly consider different factors such as the environment, and insist on waiting until the mileage is reached or the engine's operating condition is significantly abnormal before maintenance. It should be noted that if maintenance is performed at this point, not only is the damage already done irreversible, but it can also cause greater harm. More importantly, some drivers may not even be aware that the air filter can fail and continue to use it as long as there is no visible damage.

2. Identification methods

The operating condition of the air filter and when maintenance or replacement is needed can be determined as follows:

Theoretically, the service life and maintenance interval of the air filter should be measured by the ratio of the gas flow rate through the filter element to the gas flow rate required by the engine. When the flow rate is greater than the required flow rate, the filter is working normally; when the flow rate is equal to the required flow rate, the filter should be maintained; when the flow rate is less than the required flow rate, the filter can no longer be used, otherwise the engine's operating conditions will worsen, becoming increasingly worse, and may even fail to operate normally.

In practice, when the air filter element is clogged with suspended particles and cannot meet the airflow required by the engine, the engine will exhibit abnormal operating conditions, such as roaring, slow acceleration (insufficient intake, insufficient cylinder pressure), weak power (over-rich mixture causing incomplete combustion), high water temperature (combustion continues during the exhaust stroke), and increased smoke during acceleration. When these symptoms appear, it can be judged that the air filter is clogged, and the filter element should be removed for maintenance or replacement immediately.

When maintaining the air filter element, attention should be paid to the color changes on the inner and outer surfaces of the filter element. After dust removal, if the outer surface of the filter paper is clear and the inner surface is bright, the filter element can continue to be used; if the outer surface of the filter paper loses its original color or the inner surface darkens, it must be replaced.