What Does Engine Piston Slap Sound Like?
2 Answers
When engine piston slap occurs, a crisp and rhythmic metal knocking sound is emitted from the cylinder. The lower the engine temperature, the more pronounced the piston slap sound becomes. As the temperature rises, the knocking sound diminishes. Possible causes of engine piston slap include poor lubrication, low oil pressure, or insufficient oil viscosity. During engine operation, the inability to form a proper oil film between the piston and cylinder wall leads to piston slap. Automobile piston slap, also known as engine piston slap, is caused by wear between the cylinder block and piston, resulting in increased clearance. Particularly when the piston skirt wears, the knocking sound becomes notably apparent.
I've been driving for over twenty years, and the knocking sound is that distinctive metallic tapping noise inside the engine, like someone gently hammering on a tin can inside. It mainly occurs when you're climbing a hill or suddenly accelerating, producing a crisp and loud sound. This happens because the gasoline ignites prematurely in the cylinder, creating abnormal pressure fluctuations. It sounds harsh, almost as if the car is 'complaining,' warning you to pay attention to your driving habits or fuel quality. Don't ignore it, or it can damage the pistons and cylinder walls, significantly shortening the engine's lifespan. Avoid driving at low speeds in high gears too often, regularly check the fuel system and carbon buildup, and schedule routine maintenance to prevent this issue. I've seen friends who neglected this end up spending tens of thousands on major engine repairs—totally not worth it.
