How to Solve Abnormal Noise When Starting a Car Engine?
2 Answers
There are generally two reasons for a sizzling sound after the engine starts: 1. If the car hasn't been moved for a long time, the engine oil will return to the oil pan. When starting the vehicle, the valves will lack the sealing and lubrication of the oil, resulting in a sizzling sound. This is a normal situation. 2. Abnormal noise from the belt during startup. In this case, it is necessary to promptly check whether the belt has a problem. Here are the solutions for belt noise: 1. If there is belt noise, first check the assembly. The noise may be caused by friction between the timing belt and the timing cover. You can loosen the screws on the timing cover by half a turn to observe if the noise disappears. 2. Next, check the condition of the generator belt. It may be the accessory belt causing the noise. If the timing belt tension is adjusted too tightly, remove the generator and air conditioning power steering belts to determine if the issue lies with these belts. 3. The timing belt tensioner may be faulty, usually requiring replacement along with the timing belt. The noise could also be due to issues with individual engine bearings. Carefully identify the specific source of the sound. If the exact cause cannot be determined, it is recommended to visit a professional repair shop for inspection to determine the cause.
I've experienced abnormal noises when starting the engine several times, usually caused by common minor issues. The most common culprit is loose or aged belts, especially during cold starts when rubber belts shrink and produce squeaking sounds. I usually open the hood to locate the source of the noise first. If it's coming from the belt side, manually tightening it or applying some anti-slip spray can temporarily solve the problem. Insufficient engine oil is another frequent cause, where poor oil quality leads to inadequate lubrication of components, resulting in metal friction sounds. Checking the dipstick and adding quality engine oil can alleviate this. However, if the noise is more of a thumping or ticking sound, it might indicate chain slack or valve clearance issues, which require professional tools for diagnosis. Don't ignore these small noises—they often signal internal engine wear. Regular oil changes and belt inspections can prevent most abnormal sounds. During every maintenance session, I always ask the mechanic to thoroughly check the belt system—it's both reassuring and safer.
