What Causes the Ticking Sound When Starting the Engine?

[OscarAnn]

There are several reasons for the ticking sound when starting 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 vibrations and provide cushioning during engine operation, as well as to secure the engine in place. Once the engine mounts age or become loose, the engine may shake, and in severe cases, a "ticking" noise may occur. 2. Overly rich air-fuel mixture: When the engine's air-fuel mixture is too rich, symptoms include difficulty accelerating after startup, uneven engine operation; black smoke from the exhaust pipe accompanied by a ticking noise, sometimes with backfiring; reduced engine power and increased fuel consumption. 3. "Piston slap" noise: Due to poor lubrication conditions, excessive wear of the piston and cylinder walls can cause the clearance between the piston and cylinder wall to exceed normal tolerance. During engine operation, the piston skirt impacts the cylinder wall, producing a clear "ticking" sound, which is usually more noticeable at idle or low speeds.