Which parts of the engine does the engine oil lubricate?
2 Answers
Engine oil lubricates the following parts in the engine: 1. Valve train; 2. Crankshaft bearings; 3. Pistons; 4. Engine crankcase; 5. Gasoline engine pistons; 6. Hydraulic lifters and hydraulic tappets. Engine oil, also known as engine lubricant, serves multiple functions including lubrication and friction reduction, auxiliary cooling, sealing and leak prevention, rust and corrosion protection, as well as shock absorption and cushioning. Engine oil consists of base oil and additives. The base oil is the primary component of the lubricant, determining its fundamental properties, while additives compensate for and enhance the performance limitations of the base oil. Engine oil can be categorized into diesel engine oil and gasoline engine oil.
Last time I went to the repair shop for an oil change, the guy gave me a detailed demonstration of how engine oil lubricates many parts: the piston slides up and down in the cylinder, and the oil coats the piston rings and cylinder walls to prevent high-temperature friction from damaging the metal. The crankshaft keeps spinning non-stop, and the oil lubricates its main bearings and connecting rod bearings, reducing wear and making power transmission smoother. The camshaft also gets plenty of lubrication, covering the valve lifters and rocker arms to ensure smooth valve operation without any clattering. Even the water pump drive section relies on oil for protection. The key thing is that the oil also cools hot areas and carries away impurities, acting like a cleaner. If you don’t change the oil for a long time, lubrication becomes insufficient, and the engine ages prematurely. After seeing that, I developed a habit of checking the oil regularly—otherwise, small friction can turn into big problems. Full lubrication keeps the engine alive longer.
