What Causes the Abnormal Noise from the Chassis After a New Car Shuts Off?

[DelGia]

Here are the specific reasons for the abnormal noise from the chassis after a new car shuts off: 1. Disc Brake Malfunction: When the vehicle is driven at low speed on a flat road, irregular intermittent noises occur at the wheel hub area. The noise slightly intensifies as the speed increases but remains unchanged during uphill, downhill, or turning. The noise worsens when driving on uneven roads and reduces or disappears when the brake pedal is pressed. During a stationary inspection, rotating the wheel back and forth can reproduce the noise. This is caused by damage, deformation, or detachment of the brake shoe support plate, damping spring plate, or guide plate of the disc brake, which increases the gap between the brake shoe and the caliper support frame, leading to collisions and noise. Visit a repair station to fix deformed parts or replace detached ones. 2. Front Suspension Ball Joint Malfunction: When driving at low gear on bumpy roads, continuous noise is heard from the front axle area. The worse the road condition, the louder the noise, which intensifies with speed. After stopping, forcefully shaking the front of the vehicle will produce noise. On flat roads, irregular intermittent noises resembling the sound of metal breaking may occur from the front axle. This is due to excessive clearance between the ball joint and its socket, causing severe looseness. Since the ball joint socket is a sealed structure and cannot be disassembled, replacement at a repair station is the only solution. 3. Front Wheel Shock Absorber Malfunction: On flat roads, slight noise from the front of the vehicle can be heard, intensifying during sharp turns. During a stationary inspection, pressing down on the front of the vehicle to make it rebound up and down will produce noise, which becomes louder with more force. The vehicle also feels less elastic and not as smooth. This usually happens when the vehicle is frequently driven on rough roads with poor maintenance, leading to shock absorber oil leakage and damage. Depending on the severity of the damage, repair or replacement at a repair station is necessary.