What happens if motor oil is not changed for a long time?

[Millie]

The consequences of not changing the oil for a long time are as follows: 1. If the oil is not changed for a long time, as the oil's lifespan deteriorates, its lubrication ability will rapidly decline, preventing the engine from receiving proper lubrication and leading to abnormal wear. 2. Metal debris cleaned by the oil cannot be expelled and accumulates inside the engine, causing dirt and generating a large amount of sludge. 3. The engine may experience increased fuel consumption, reduced power, difficulty starting, abnormal shaking, and poor operation. In severe cases, the engine may be directly rendered unusable. Here are the functions of motor oil: 1. Lubrication: There are many moving friction surfaces inside the engine. The oil forms a film between these surfaces to achieve lubrication and anti-wear effects. 2. Cleaning: The movement of engine components causes wear and produces metal debris. The oil continuously circulates inside the engine through the action of the oil pump and carries these metal debris back to the oil pan. 3. Cooling: The continuous circulation of oil inside the engine can carry away the heat generated by the engine and cool it through the oil cooler. 4. Sealing: The oil film formed on the surface of the engine cylinder walls and the inner surface of the valve guides can provide a sealing effect to prevent leaks.