What Causes the Clunking Noise in the Chassis When Accelerating or Decelerating?
2 Answers
When accelerating or decelerating, the clunking noise in the chassis can be caused by the following reasons: Suspension System: The noise heard when starting the vehicle is usually due to a fault in the suspension system, which may be caused by loose or damaged engine mounts. Steering and Suspension Systems: The noise heard when turning the vehicle may be due to faults in the steering and suspension systems, as the vehicle tilts during turning, causing the suspension system to deform and participate in the movement. Braking System Components: The noise heard when driving on good road conditions may be due to faults in the braking system components, such as loose or worn parts, out-of-round brake drums, or uneven brake discs. Bearing System: It could also be an issue with the bearings that connect moving and stationary parts of the vehicle. If it's a bearing problem, the driver can identify it by applying slight brakes. If the noise remains unchanged when braking at a constant speed, then the issue is with the bearings.
Last time my car made a clunking noise from the chassis when accelerating, and another noise when releasing the throttle. I specifically researched common faults. First is the wear of driveshaft components, especially when the CV joint is loose - torque changes cause impact noises. Then there's aging and cracking of the rubber bushings in suspension control arms, causing insecure connection between wheels and body - the chassis feels like falling apart when stepping on the gas. Also often overlooked are loose subframe mounting bolts - use a torque wrench to check if they meet specifications. Additionally, broken exhaust hangers on older cars cause the exhaust pipe to hit the frame during acceleration. I recommend first visually inspecting visible chassis bolts and bushings, then having a repair shop use a lift to check drivetrain clearances - safety should never be compromised.
