Why Does a Sedan Make a Clunking Sound When Driving on Uneven Roads?
2 Answers
The reasons why a sedan makes a clunking sound when driving on uneven roads: 1. Loose Ball Joint of the Control Arm: If the ball joint of the lower control arm is loose with excessive clearance, it will produce abnormal noises when the car bumps. 2. Aging Plastic Components: Loose or excessively gapped stabilizer bar bushings. 3. Damaged Shock Absorber: A damaged shock absorber can also cause abnormal noises when the car passes over uneven roads. Although shock absorbers have a relatively long service life, they are still a vulnerable part of the car; if the driving environment is poor or the car is frequently driven aggressively, damage or oil leakage is inevitable. 4. Aging Buffer Rubber: The connection points between the shock absorber and the car body are cushioned with rubber. Rubber products will harden and age after prolonged use; when hardened rubber is squeezed, it produces a clunking sound.
I encountered this kind of clunking noise last time I drove on rough roads, it sounded like something was fighting under the chassis. After a careful inspection, I found that the lower control arm bushings were worn out—the rubber had cracked, causing the metal parts to directly hit and make noise. This is a common issue for cars over ten years old, and the sound becomes even more noticeable when going over speed bumps on rainy days, which should raise a red flag. Another possibility is loose tie rod ends—you can feel the play when shaking the tire. If a suspension spring is broken in half, it can also make a rattling noise, though this is less common. I recommend lifting the car and shaking the wheels; if there's any play, it needs to be fixed immediately, otherwise, the steering could go off, which is dangerous. A friend’s car had this issue and delayed repairs, resulting in the ball joint nearly coming off and almost causing an accident.
