What Causes the 'Clunk' Sound When a Car Starts Moving?

[Susan]

Car starts moving with a 'clunk' sound for the following reasons: Aging of certain components in the car's chassis: In fact, aging of certain components in the car's chassis can often cause a 'clunk' sound when the car starts moving. After a period of time, the suspension ages very quickly because some supporting parts inside the car gradually lose their original function. Rust symptoms in the car's braking system: If the car is in a damp and rainy area for a long time, its brake discs will gradually rust due to such weather. In areas with more rain, brake discs are more prone to oxidation and rust. Therefore, when the car starts moving, the braking system may produce a 'clunk' sound. Presence of foreign objects in the car's wheels: When the car is driven on surfaces with a lot of debris, some foreign objects may enter the car's tires. If these foreign objects remain for a long time, they can cause the car to make a 'clunk' sound when starting to move.

[Anastasia]

I've been driving for over twenty years, and I've encountered the issue of a clunking sound from the chassis during startup several times. Most of the time, it's due to problems with the suspension system, such as aging ball joints in the shock absorbers or the rubber bushings of the lower control arms. These parts tend to loosen over time and make noise when you step on the gas. Brake pad sticking is also a common issue, especially in cold weather or during the rainy season, where the wheels get stuck and produce a clunking sound upon startup. Once, I was on a road trip when this sound appeared, and it turned out to be a worn-out universal joint on the drive shaft. If the sound is minor, it might just be due to bumps and vibrations—no need to worry too much. But if it happens every time or gets louder, it's best to take it to a repair shop. Ignoring chassis issues can lead to unstable handling and increased danger, especially at high speeds in rainy conditions. You can check if the wheels are loose yourself, but it's better to consult a professional mechanic to avoid higher repair costs later.