What Causes the Clunking Sound When a Car Goes Over Speed Bumps?
3 Answers
Car over speed bumps clunking sound reasons are as follows: Excessive clearance between piston and cylinder wall: Piston pin installed too tightly or connecting rod bearing installed too tightly; Excessive clearance between tappet and its guide hole; Wear of cam profile; Sometimes, the starting claw is loose causing the pulley to make noise (especially noticeable during speed changes). Loose camshaft timing gear: Camshaft timing gear cracked or its fixing nut loose; Crankshaft broken; Loose piston pin bushing; Excessive axial clearance of camshaft or loose camshaft bushing. Crankshaft broken: Loose connecting rod bearing, bearing shell melted or incorrect size causing rotation; Loose crankshaft bearing or melted bearing shell; Broken piston pin; Broken crankshaft.
A loud clunking sound when going over speed bumps is often caused by issues with the suspension system. If the shock absorbers in the suspension system are aged or leaking oil, they cannot effectively absorb vibrations, resulting in loud noises. Additionally, worn or loose bushings in the stabilizer bar or control arms can also create metallic clashing sounds when going over bumps. Loose fasteners are another common issue—especially if the suspension mounting points are not tightened properly, causing rattling noises every time the car crosses a speed bump. Damaged tires or wheel hub bearings can also exacerbate the problem, as components rub against each other when the vehicle experiences impact. It is recommended to visit a repair shop as soon as possible to inspect the shock absorbers and suspension components to prevent further deterioration and ensure driving safety. Also, maintaining good tire condition will make daily driving smoother.
My car had the same issue before, making a loud clunking noise every time it went over a speed bump, which was really annoying. After checking, it's usually because the shock absorber is broken or loose. Long-term bumps can cause it to wear out and become brittle, making a sound like metal hitting metal. Sometimes it's the brake disc or the suspension ball joint screws that are loose; if they're not tightened properly, they'll rattle. If the sound is a continuous clicking noise, it might be due to aging or deformation of the chassis bracket, which needs adjustment. A friend of mine had a similar situation with his car—it turned out to be a broken lower control arm link. The repair wasn’t too expensive, but it needed to be fixed promptly. In short, don’t ignore such noises. Take your car to a 4S shop or repair shop, lift it with a jack to inspect the chassis, and reinforce any loose parts. Preventing major repairs is definitely worth it.
