What Causes the Chassis to Make Abnormal Noises on Bumpy Roads?
2 Answers
Reasons for abnormal noises coming from the car chassis on bumpy roads: 1. Displacement, deformation, or damage to the buffer rubber sleeves or blocks in the suspension components. Deformation, oil leakage, or damage to internal parts or rubber sleeves in the shock absorber section. 2. Vibrations caused by impacts on the elastic components in the suspension system. To improve the smoothness of the vehicle's ride, shock absorbers are installed in parallel with the elastic components in the suspension to attenuate vibrations. 3. Contradictions arise between adjusting the elastic components and the shock absorbers. Most shock absorbers used in car suspension systems are hydraulic shock absorbers. Their working principle is that when relative movement occurs between the frame (or body) and the axle due to vibrations, the piston inside the shock absorber moves up and down, causing the oil in the shock absorber chamber to repeatedly flow from one chamber to another through different pores. At this time, the friction between the pore walls and the oil, as well as the internal friction between oil molecules, creates a damping force that converts the car's vibration energy into heat energy of the oil, which is then absorbed and dissipated into the atmosphere by the shock absorber. When factors such as the cross-sectional area of the oil passage remain unchanged, the damping force increases or decreases with the relative movement speed between the frame and the axle (or wheels) and is related to the viscosity of the oil. The shock absorber and elastic components bear the tasks of cushioning impacts and damping vibrations. Excessive damping force will impair the elasticity of the suspension.
I often encounter the issue of chassis noise on bumpy roads while driving. The sound is like metal clanging or screws rattling, which gives me a headache. There could be many reasons, mainly due to aging suspension system components, such as cracked rubber bushings on the shock absorbers or loose ball joints on the control arms—it tends to make more noise on uneven roads. Rusted tie rod or stabilizer bar links could also cause noise. For a DIY check, find a flat surface, open the engine compartment, and look underneath for any obvious loose parts, or use a jack to lift the car and shake the wheels to test for play. For a proper diagnosis, it's best to visit a repair shop and let a professional mechanic lift the car for a detailed inspection—safety first, as small issues left unattended could lead to problems with braking or handling. It's recommended to regularly clean accumulated mud from the chassis during maintenance to prolong component lifespan.
