What Causes the Abnormal Noise When a Car Just Starts?

[MacJaxson]

Abnormal noise after starting the car is most likely due to engine belt failure or loose engine mount bolts causing engine vibration and a buzzing sound. Here are the specific details: 1. If the engine mount bolts are loose, you can find and tighten the screws yourself. If it's an engine belt issue, first check the belt's tension. You can try pinching the drive belt with your fingers and then twisting it. Note that this operation should be performed when the engine is cool, and the twist angle should generally be less than 90 degrees; otherwise, adjustment is needed. 2. Sometimes, if the car belt is loose, it may produce a buzzing sound. You should take the car to a repair shop to check the belt and tighten it appropriately to see the effect. Regular belt maintenance is essential, and the tension should be moderate.

[DiIsabelle]

It's quite common to hear rattling or squeaking noises when starting the car. I've encountered this odd issue a few times over my decade-plus of driving. The main cause is aging and loosening engine belts, especially rubber-made alternator belts or timing belts. After several years of use, they harden and become brittle, causing friction noises upon startup. Another possibility is poor oil fluidity; during cold morning starts, components aren't fully lubricated, resulting in dry, harsh noises. Or, it could be a faulty starter—worn bearings can produce sounds. Last time, I spent a small amount at the repair shop to replace the belt, and the issue was resolved. Don't delay fixing it, as a broken belt can affect drive systems and lead to dangerous stalling while driving. Regular checks of these components can prevent problems, especially paying attention to oil quality in colder weather.

[Tim]

The abnormal noise that occurs at the moment of car startup is usually related to belt issues. For example, if the timing belt is loose or cracked, it may squeal when rotating at high speed during startup. It could also be caused by excessive friction from an overly tight water pump or fan belt. Another important factor is the hydraulic tappet not working promptly, which can cause a rattling sound during cold starts when oil pressure is insufficient. I've seen many car enthusiasts discuss this, and older vehicles are more prone to such issues, especially in northern winters when temperatures drop below zero. It's recommended to have a technician check the belt condition and oil viscosity during each maintenance service, and adjust or replace them if necessary. Although the noise may seem minor, it can accumulate over time and indicate underlying problems. Addressing it early can prevent costly engine damage repairs.

[LeGage]

If there's abnormal noise when the car just starts, it's most likely a drive belt issue. The squealing sound could be from an aged and loose belt rubbing, or possibly due to worn starter bearings or cracks in the belt. Quick fix: After starting, listen to locate the noise source – if it's from the front of the engine, it's probably the belt. You can try manually tightening it but avoid random adjustments. If that doesn't work, visit a repair shop for a replacement, usually costing a few hundred yuan. Ignoring such minor noises may lead to belt breakage affecting power transmission. For safety, don't delay maintenance.

[WyattMarie]

That rattling noise when starting the car is quite annoying. I've experienced it myself, caused by loose belts or insufficient oil leading to dry component friction. Cold weather thickens fluids, making it more likely to occur. I recommend warming up for a few seconds before starting, then paying attention to the frequency and location of the sound. If it persists, don't delay—get it checked by a professional promptly. Don't underestimate this noise; it might mask bigger issues like engine wear, which could increase breakdown risks in severe cases. Regular oil changes and belt maintenance are key to avoiding skyrocketing repair costs and ensuring safer driving.