What Causes the Ticking Sound in a Car?

[SanHailey]

The possible causes of abnormal sounds in a car are as follows: 1. Valve noise: After starting the engine, you may hear a "ticking" sound, which is the sound of the valves. This is especially noticeable when the engine is cold, as the oil pressure hasn't built up yet and the valves aren't properly lubricated. The sound should disappear after a short while. 2. Insufficient lubrication: Generally, when a car is cold-started, the engine sound may be slightly louder than when it's warm. As long as the sound is even and smooth, not harsh, it's usually not a problem. This is because when the engine is cold, the gap between the cylinder wall and the piston hasn't reached the optimal size, and the oil lubrication isn't fully effective. Normally, when the engine block temperature reaches about 95 degrees, the sound will return to normal. 3. Oil-related issues: Poor-quality oil, not changing the oil for a long time, or low oil levels can all increase friction between the valves and guides, as well as in components like hydraulic lifters, making various sounds in the engine louder.