Sludge refers to the fuel residue inside the engine. Also known as carbon slime, it is retained in the engine oil and filtered by the oil filter. But if the oil or oil filter is not replaced, the sludge will accumulate and the oil will become dirty and deteriorated. If the oil is black, it is probably caused by sludge, so the oil needs to be changed.

First of all, is this sludge normal? It should be abnormal. There are also many people who explain that this kind of greasiness is normal and every engine will have it. This statement is wrong. The oil is pumped by the oil pump to various parts of the engine through the filter screen, and then returns to the oil filter element from top to bottom. The impurities are filtered and flow to the oil pan. This sludge can be said to be several times the viscosity of the oil, basically does not have the performance of the fluid, will be firmly adsorbed on the surface of the oil pump filter. The filter cannot effectively inhale enough oil, which will affect the circulation performance of the oil, accelerate the deterioration of the oil, and the sludge will increase. The oil has a cooling effect in the engine, and insufficient flow leads to local high temperature of the oil, which is the root cause of sludge.

The oil filter element will leave residues in the filter element during the oil circulation process. If the oil circulation is normal, the sludge should be in the oil filter element, not adsorbed on the surface of the oil pump filter. Turbocharged engines can use low-viscosity oil, but for ordinary engines, change the correct type of oil, the sludge is not caused by oil problems. Of course, fake oil is another matter.

The oil filter element will leave residues in the filter element during the oil circulation process. If the oil circulation is normal, the sludge should be in the oil filter element, not adsorbed on the surface of the oil pump filter. Turbocharged engines can use low-viscosity oil, but for ordinary engines, change the correct type of oil, the sludge is not caused by oil problems. Fake oil, of course, is another matter.

The task of the air filter is to filter the suspended particles in the air entering the cylinder to reduce the wear of the cylinder, piston and piston ring. Of the three media required for engine operation, the largest amount of air comes from the atmosphere. If the air filter cannot effectively filter the suspended particles in the air, the lighter ones will accelerate the wear of the cylinder, piston and piston ring, and the heavier ones will cause the cylinder to strain and shorten the service life of the engine.

In theory, the service life and maintenance cycle of the air filter should be measured by the ratio of the gas flow through the filter element to the gas flow required by the engine. When the flow rate is greater than the flow rate, the filter works normally; when the flow rate is equal to the flow rate, the filter should be maintained; when the flow rate is less than the flow rate, the filter can no longer be used, otherwise the working conditions of the engine will deteriorate. The situation is getting worse and worse, even unable to work.
In actual work, when the air filter element is blocked by suspended particles and cannot meet the airflow required by the engine, the engine working state will be abnormal, such as roaring sound, slow acceleration (insufficient intake air volume, insufficient cylinder pressure), Weak work (the mixture is too rich to cause incomplete combustion), the water temperature is relatively high (continue to burn when entering the exhaust stroke), and the smoke becomes thicker when the exhaust accelerates. When these symptoms occur, it can be judged that the air filter is clogged, and the filter element should be removed for maintenance or replacement in time.
When maintaining the air filter element, pay attention to the color change of the inner and outer surfaces of the filter element. After dust removal, the outer surface of the filter paper is clear and the inner surface is bright, and the filter element can continue to be used; if the outer surface of the filter paper loses its original color or the inner surface becomes dark, it must be replaced.

In the air cleaner instruction manual, although mileage or working hours are specified as maintenance or replacement data. But in fact, the maintenance and replacement cycle of the air filter is also related to environmental factors.
For cars that often drive in dusty environments, the maintenance or replacement cycle of the air filter should be shortened; for dusty cars, the maintenance or replacement cycle of the air filter is sufficient. Prolonged appropriately.
In actual work, many drivers and maintenance personnel act mechanically according to the regulations and do not have the flexibility to grasp different factors such as the environment. They insist on waiting for the mileage to reach the standard and the engine working condition to be obviously abnormal before carrying out maintenance. It should be noted that if repairs are carried out at this time, not only the losses that have been caused cannot be recovered, but also greater harm will be caused. What's more, individual drivers do not even know that the air filter will fail, as long as the appearance is not damaged, continue to use.