What Causes the Occasional Scraping Sound Under the Car While Driving?
2 Answers
Introduction to the causes of occasional scraping sounds under the car while driving: Steering system malfunction: When the car turns, abnormal noises from the chassis may be caused by faults in the steering system or suspension system. During the turning process, the tilt of the vehicle causes deformation of the suspension system. Brake system component failure: When driving on good road conditions, abnormal noises from the chassis may be caused by faults in brake system components, such as loose or worn brake system parts, out-of-round brake drums, or uneven brake disc surfaces. Bearing issues: Abnormal noises from the chassis may also be caused by problems with the bearings that connect moving and stationary parts of the vehicle. If there is a bearing issue, the driver can identify it by lightly applying the brakes. If the braking sound remains unchanged during uniform motion, it indicates a bearing problem. Suspension system abnormality: When driving on poor road conditions, abnormal noises from the chassis are mostly due to suspension system abnormalities or loose brake systems. The sounds from the suspension system are mostly friction noises.
Sometimes when I'm driving in the city, I suddenly hear a clicking sound from the chassis scraping, which is a bit annoying because it often happens on uneven roads, like running over small stones, curbs, or potholes, especially when going over speed bumps. Recalling my last maintenance visit, the mechanic mentioned that it might be due to loose chassis components such as the exhaust pipe or oil pan not being properly secured; or the vehicle's ride height being too low, like in some older cars where worn shock absorbers cause the entire body to sag. Other times, it could be small stones getting stuck and rolling around in the gaps of the chassis. Safety first—when I hear such sounds, I slow down and then find a place to stop as soon as possible to check for any damage to the chassis. If necessary, I take it to a repair shop to have professionals check for loose bolts, deformed underbody panels, or suspension system issues. For daily driving, it's advisable to avoid forcing the car over bumps, especially on slippery rainy days when extra caution is needed.
