When the vehicle goes downhill, there will be abnormal noise because the parts are loose. When the vehicle is driving at a low speed on a flat road, it will make an intermittent and irregular "quack" sound at the axle, which will be slightly aggravated when the vehicle speed increases, but it will not change when going uphill, downhill and turning. When driving on uneven roads, the noise intensifies, and the noise of stepping on the brake pedal with your feet decreases or disappears. When parking, you will hear abnormal noise when turning the wheels back and forth. This is because the brake shoe support plate, damping spring plate or guide plate of disc brake are damaged, deformed and dropped, which makes the gap between brake shoe and caliper support frame increase up and down, left and right, and collide with each other to make sound. You can repair the deformed parts and replace the dropped parts at the repair station.

1. Touch the tread pattern of the tire by hand. If you can feel uneven tread patterns on the inside or outside, it must be the cause of abnormal noise. Be sure to do four-wheel alignment before changing tires. I suggest you check what you put in the car. Sometimes you put it in a drawer or compartment. When something in the trunk shakes on the uneven road, it will make a noise. Don't blame the car.

2. Look at the seat belt button on the seat, and it's easy to throw it around. The seat belt button in the back seat is always played by children for a while, and then it often makes noise when it hits the car body. Check the distance between several wheels. Sometimes foreign objects get stuck in it. When bumping, there will be abnormal noise when colliding with tires or wheels.

3. Vehicles usually run on bad roads and are not properly maintained, resulting in oil leakage and shock absorber damage. In the repair shop, this situation should be repaired or replaced according to the severity of the damage. If the noise encountered during driving comes from the gearbox, it may be caused by the spot wear of gearbox bearings or gears and bearings. The abnormal sound of gearbox during gear shifting may be caused by metal powder in gearbox oil, which indicates that the brake band, clutch and other parts in gearbox are excessively worn. The above is the answer to the question about abnormal noise when the vehicle goes downhill. What's going on here?