Oil filter, also known as oil grid. Used to remove impurities such as dust, metal particles, carbon deposits and soot particles in the engine oil to protect the engine.

The oil filter is divided into full-flow type and split-flow type. The full-flow filter is connected in series between the oil pump and the main oil passage, so it can filter all the lubricating oil entering the main oil passage. The split-flow cleaner is connected in parallel with the main oil passage and filters only part of the lubricating oil sent by the oil pump.

During the operation of the engine, metal abrasive debris, dust, carbon deposits oxidized at high temperature and colloidal precipitates, water, etc. are continuously mixed into the lubricant. The role of the oil filter is to filter out these mechanical impurities and colloids, to keep the lubricant clean and extend its service life. The oil filter should have such features as strong filtering capacity, low flow resistance and long service life. The general lubrication system is equipped with several filters with different filtration capabilities-collector filter, coarse filter and fine filter, which are connected in parallel or in series in the main oil channel. (The full-flow filter is connected in series with the main oil passage, and the lubricating oil is filtered by the filter when the engine is working; the split-flow filter is connected in parallel with it). Among them, the coarse filter is connected in series in the main oil passage and is a full-flow type; the fine filter is connected in parallel in the main oil passage and is a split-flow type. Modern car engines generally only have a collector filter and a full-flow oil filter. The coarse filter filters out impurities with a particle size of 0.05mm or more in the engine oil, and the fine filter is used to filter out fine impurities with a particle size of 0.001mm or more.