Clicking Sound in Chassis When Accelerating and Releasing the Throttle?
4 Answers
This situation may be caused by damage to the suspension control arm bushings or failure of the CV joint. If this occurs, it is essential to have the CV joint and suspension control arm bushings inspected at a 4S shop. If the suspension control arm bushings are damaged, they should be replaced immediately. Below is the relevant information: 1. Function of Automobile Suspension Control Arm Rubber Bushings: The connection points of automobile suspension control arms are equipped with rubber bushings, which enhance driving comfort and handling quality. However, rubber components can deteriorate over time with prolonged use. 2. Hazards of Aging Automobile Suspension Control Arm Rubber Bushings: If the rubber bushings on the suspension control arms age, the clearance in the control arms will increase, leading to abnormal noises in the chassis and negatively affecting the vehicle's handling and comfort. If the rubber bushings on the suspension control arms are aged, they must be replaced promptly.
I've been driving for almost twenty years and have encountered this kind of thumping noise when accelerating or releasing the throttle several times. The most common cause is aging and cracking of the rubber bushings in the chassis, especially the control arm bushings and front stabilizer bar bushings, which creak when under stress. There are also many issues with the drivetrain, such as worn CV joints, loose universal joints in the driveshaft, and excessive gear backlash during shifting, which can also cause a thump. Last time, the abnormal noise in my car was caused by collapsed engine mounts—when accelerating, the engine rocked back and forth and directly hit the chassis frame. Nowadays, mechanics say chassis noises are the hardest to diagnose; they have to lift the car and shake each component to find the play. I recommend getting it checked early, as these small issues left untreated can lead to suspension deformation or even driveshaft failure, which is especially dangerous at high speeds.
As an enthusiast who often tinkers with cars, I recommend starting with basic troubleshooting. Park on a level surface, engage the handbrake, then try rocking the car back and forth to see if the clunking noise reappears. Open the hood to inspect the engine mount rubber blocks, and gently shake the engine with a pry bar to check for excessive movement. For the chassis, focus on checking for play in the tie rod ends and lower control arm ball joints, and see if the stabilizer bar bushings are cracked. If you can't figure it out yourself, take it to a repair shop and have the mechanic test it on a lift, observing the movement of chassis components while revving the engine. Such noises are mostly metal-on-metal impact sounds, possibly due to loose subframe bolts or broken exhaust pipe hangers. Remember to bring a dashcam recording of the noise for the mechanic's reference.
Both of my family's cars have had this issue, and I've summarized several typical scenarios. The first is a 'clunk' sound during sudden acceleration, which is often caused by wear in the inner CV joint of the drive axle creating clearance noise. The second is a noise when suddenly lifting off the throttle, mostly due to excessive clearance in the differential gears or a damaged transmission mount. Last week, a neighbor's car was diagnosed with a shattered center support bearing in the driveshaft, where metal balls fell out and caused a rattling noise. Rubber bushing problems are usually more noticeable when the car is cold, while metal component failures often worsen with speed. For safety, avoid highway driving if you hear such noises and get it checked at a shop as soon as possible. Repair costs can range from a few hundred for replacing bushings to several thousand for replacing an axle, but delaying repairs may lead to more severe mechanical damage.
