What Causes the Ticking Sound in the Engine?
2 Answers
Reasons for the ticking sound in the engine: 1. Aging or loosening of engine mounts: Engine mounts are rubber blocks placed between the engine and the frame. Their purpose is to reduce vibration and absorb shocks during engine operation, as well as to secure the engine. Once these mounts age or become loose, the engine may shake, and in severe cases, produce a "ticking" noise. This can usually be resolved by replacing the engine mounts. 2. Overly rich air-fuel mixture: When the engine's air-fuel mixture is too rich, symptoms include difficulty accelerating after starting, uneven engine operation, black smoke from the exhaust pipe, a ticking noise from the engine, reduced engine power, and increased fuel consumption. This is often related to carbon buildup or clogged filters and generally does not require major repairs. 3. "Piston slap" noise: Due to poor lubrication or excessive wear of the piston and cylinder walls, the clearance between the piston and cylinder exceeds normal tolerances. During operation, the piston skirt strikes the cylinder wall, producing a clear "ticking" sound, which is usually more noticeable at idle or low speeds.
I've worked in an auto repair shop for over a decade and often hear car owners complain about engine rattling sounds. This noise is mostly caused by issues with the engine's valve train, such as aging hydraulic lifters or excessive clearance, which becomes more noticeable with poor lubrication. Worn piston pins or connecting rod bearings can also produce similar rhythmic sounds, resembling small hammers tapping inside the engine. Another common cause is a loose timing chain that hits the chain cover. Insufficient oil or unstable oil pressure can worsen these noises, so it's crucial to check oil level and quality immediately. Neglecting this long-term may damage core engine components, leading to expensive repairs. I recommend promptly visiting a shop to locate the sound source with a stethoscope and trying an oil top-up first. Additionally, temporary rattling during cold starts isn't usually serious, but persistent cases warrant attention—don't let it escalate into major trouble.
