How to Determine if Engine Oil Needs to Be Changed

[StIan]

Here are the methods to determine if the engine oil needs to be changed: 1. Check the oil quality—if the color turns black and smells sour, it needs to be replaced; 2. Use your fingers to check if the oil still has viscosity; 3. Difficulty shifting gears when starting a cold engine. The steps to change the engine oil are as follows: 1. Remove the air filter, clean it using an air pump, and reinstall it; 2. Lift the vehicle, unscrew the drain plug to release the old oil, and remove the oil filter; 3. Add approximately 3.5 liters of new oil. The functions of engine oil include: 1. Reducing friction and high temperatures; 2. Cooling and lowering temperature; 3. Cleaning and removing contaminants; 4. Dampening vibrations and shocks; 5. Preventing rust and corrosion.