What Causes the Ticking Noise in Car Engine at Idle?
2 Answers
Car engine making abnormal noise at idle can be attributed to the following reasons: 1. Valve noise: The "ticking" sound after starting the engine is typically caused by valves, especially noticeable during cold starts when oil pressure hasn't built up yet and valve lubrication isn't optimal. This condition usually improves after a short period. 2. Insufficient lubrication: Most vehicles exhibit slightly louder engine noise during cold starts compared to warm operation. As long as the sound remains even and smooth (not harsh), this is normal. The noise occurs because the clearance between cylinder walls and pistons hasn't reached optimal dimensions during cold operation, combined with inadequate oil lubrication. The sound typically normalizes when engine block temperature reaches about 95°C. 3. Oil-related issues: Using substandard oil, prolonged oil change intervals, or low oil levels can increase friction between valves and guides as well as hydraulic lifters, thereby amplifying various engine noises.
The car makes a ticking noise at idle, and I've experienced this several times. The most common cause might be a problem with the hydraulic lifters. When the engine oil is too low or of poor quality, the lifters can't lubricate properly, resulting in continuous knocking sounds. A loose timing chain or belt is also a major suspect—at idle, the engine vibrates more, causing the chain to rattle. Sometimes, the fuel injectors produce similar sounds at low RPMs, but that's generally normal and nothing to worry about. If the valve clearance isn’t adjusted properly, the valve tappets have gaps, leading to a noticeable ticking sound at idle. It's important to check the oil level immediately; if it's low, top it up or replace the oil. If the noise persists, don’t ignore it—take the car to a repair shop for inspection. Delaying repairs could damage the cylinders or pistons, leading to costly repairs. Regular maintenance is key—checking the oil condition monthly can prevent minor issues from escalating.
