What Causes Abnormal Noise When a Car Just Starts?

[LailaFitz]

Car just starts when there is abnormal noise for the following reasons: Bearing wear and damage: When the bearing is damaged, because the bearing cannot operate normally, it will produce abnormal noise, and even cause damage to the transmission components in the gearbox, resulting in the expansion of the fault. The wear of transmission components or the selection of parts with too low precision during replacement, such as gear wear or the excessive fit clearance between the new gear and the original gear. Poor lubrication of lubricating oil: At this time, the corresponding lubricating oil should be replaced, otherwise it will aggravate the wear of the gearbox and shorten the service life. Loose gearbox bolts: The vibration during use loosens the bolts, which will cause abnormal noise when starting. Regular inspection is required.

[IvanDella]

With years of experience in car repair, I've encountered many car owners reporting abnormal noises during initial acceleration, with brake system issues being the most common. For example, after the car has been parked overnight or after rain, rust forms on the brake discs, resulting in a squeaking sound when releasing the brakes upon starting—this is usually a normal short-term phenomenon. However, if it persists, it may indicate severe wear of the brake pads requiring replacement, otherwise, it could affect braking efficiency. Additionally, aging rubber bushings in the suspension system can cause a rattling noise when the vehicle starts, especially noticeable at low speeds over speed bumps. Furthermore, wear in the driveshaft universal joints might lead to a clunking noise, sounding like gears getting stuck. While these noises may not pose immediate danger, prolonged neglect can accelerate component wear and even lead to safety hazards. I recommend having these points checked by a technician during routine maintenance, using a multimeter to test voltage and lubricate components to prevent potential issues. Recording the specific conditions when the noise occurs, such as on wet roads or at certain speeds, can help repair shops diagnose the problem accurately.

[Raymond]

I've been driving for decades and have encountered several instances of unusual noises when starting the car. One particularly loud case happened on a freezing winter day when there was an issue with the rear suspension. The car made a creaking sound as soon as it moved, and it turned out to be due to hardened, aged bushings on the shock absorbers that produced noise under pressure, especially noticeable during low-speed turns. Then there's the braking system—when brake pads get damp and rusty, they can squeak upon starting, which is common after rain or snow. Don't underestimate these sounds. When I was younger, I often ignored them, only to end up with severely worn universal joints on the driveshaft that clunked loudly before I finally got them fixed, costing me unnecessary extra money. Now I've learned my lesson: every season during oil changes, I remind the mechanic to thoroughly inspect the suspension's rubber components and brake assemblies. After all, as a car ages, its parts are more prone to fatigue, and regular lubrication can extend their lifespan. Safety is crucial—frequent unusual noises might affect handling stability, especially when starting in heavy traffic, where the risk of accidents is higher.