If you're driving and you hear a thumping noise, it's possible that you have an unbalanced tire. This can happen when the weight of the tire isn't distributed evenly around the circumference. When this happens, the tire will start to bounce on the ground, which can create a thumping noise. If you think you might have an unbalanced tire, it's important to get it checked out as soon as possible. Driving with an unbalanced tire can cause premature wear and tear on other parts of your car, like the suspension.