Change the oil and drain it well. No matter where the oil is changed, the oil is released by natural gravity. The functions of oil are:
1. Lubrication: There is rapid relative sliding between the piston and the cylinder, between the main shaft and the bearing bush. To prevent the parts from wearing too quickly, an oil film needs to be established between the two sliding surfaces. There is a sufficient thickness of oil film to separate the surfaces of the relatively sliding parts, so as to achieve the purpose of reducing wear;
2. Auxiliary cooling and cooling: The oil itself does not have a cooling effect due to its low specific calorific value and inside the engine. However, heat energy is generated in the engine due to the combustion of fuel. When the engine is working, the oil can bring the heat back to the oil tank and then dissipate it into the air to help the water tank to cool the engine. The real cooling effect is the water or antifreeze liquid outside the engine shell;
3. Cleaning and cleaning: Good engine oil can bring the carbide, sludge and wear metal particles on the engine parts back to the oil tank through circulation, and wash the dirt generated on the working surface of the parts through the flow of lubricating oil;
4. Sealed and leak-proof: The oil can form a sealing ring between the piston ring and the piston to reduce the leakage of gas and prevent the entry of external pollutants;
5. Anti-rust and anti-corrosion: lubricating oil can be absorbed on the surface of the parts to prevent water, air, acidic substances and harmful gases from contacting the parts

Oil filter replacement steps:
1. Drain the waste oil, first drain the waste oil in the fuel tank of the car, place the old oil container under the oil pan, open the oil drain bolt, and drain the waste oil. When draining the oil, let the oil drip for a period of time to ensure that the waste oil is drained cleanly;
2. Remove the old oil filter element, move the old oil container to the bottom of the machine filter, and remove the old filter element. Be careful not to contaminate the inside of the machine with waste oil;
3. The vehicle is a vertically installed oil filter. This installation method generally recommends that users replace the filter and fill the filter with oil first. The horizontally installed oil filter element does not need to be filled with oil before the filter element is installed.