What Causes the Sound of a Sticky Plastic Bag When the Car is Running?
2 Answers
Possible reasons include too many stones stuck in the wheels, causing resonance with the fender liners. Below are related explanations: Wind noise: For a new car, after excluding issues with the bearings and foreign objects in the tires, it is preliminarily judged as wind noise. (It is indeed wind noise.) When the car is moving, air convection creates wind pressure on both sides of the vehicle. When this wind pressure encounters obstacles (such as barriers, poles, or walls on either side of the car), it creates resistance, leading to noise. Frequency: The frequency and intensity of the noise are related to the shape of the obstacles on both sides of the vehicle. For example, pole-shaped obstacles produce rhythmic noise, while walls generate continuous noise. In fact: Riding a motorcycle or electric vehicle (at high speeds) on the same road section can also produce this noise.
That plastic sticking sound while driving is quite common, usually caused by tires or chassis issues. If it sounds like a plastic bag flapping in the wind, there's an 80% chance a foreign object is stuck in the wheel hub or undercarriage. I've experienced this myself – after pulling over, I found a small plastic bag stuck to the inner side of the rear tire. In such cases, it's best to safely pull over and visually inspect the tires and undercarriage. Deeply lodged debris may cause tire wear through friction or even affect steering. Other causes include loose plastic guards, such as side skirts or air deflectors rubbing during high-speed vibrations, producing similar noises. I recommend routinely cleaning tire grooves during car washes as preventive maintenance. Safety first – never delay repairs when issues are detected.