What Causes the Squeaking Noise When a Car Goes Over Bumpy Roads?
2 Answers
Causes of squeaking noise when a car goes over bumpy roads: 1. Issues with the suspension system. The suspension is a system, not just a single component, and includes parts such as links, springs, shock absorbers, and stabilizer bars. Any problem with these parts can cause abnormal noises when the car goes over bumpy roads. 2. A broken shock absorber can result in the car having no damping or rebound when going over bumpy roads, making it prone to abnormal noises when passing speed bumps or rough surfaces. 3. Problems with the stabilizer bar bushings. The stabilizer bar, also known as an anti-roll bar or sway bar, has two clips containing the bushings. Exposure to winter cold, summer heat, and erosion from dirt and dust can cause the bushings to harden over time. This leads to inconsistent heights of the left and right wheels when the car goes over uneven roads, producing squeaking noises.
With over a decade of auto repair experience, I've found that squeaky chassis noises usually indicate loose suspension components. The most common culprit is worn-out stabilizer bar bushings – when the rubber hardens and cracks, it creates metal-on-metal grinding that squeaks over bumps. Worn control arm ball joints will produce clunking sounds, and you can feel play when shaking the wheel by hand. Damaged shock absorber top mounts behave similarly, creaking when turning the steering wheel at standstill. Recently I serviced a car with completely split lower arm bushings where bare metal was grinding, making rusty-hinge noises over speed bumps. Aftermarket underbody protection plates are also worth checking – loose fasteners or contact with exhaust pipes can cause resonant rattles. My advice: get the car on a lift and have a mechanic shake the suspension components – this method catches about 80% of such issues.
