A bubble in the sidewall is one tire problem you should take seriously. At first, it may look like a small raised spot, almost as if someone pushed outward from inside the tire. In reality, that bulge usually means the tire's internal structure has been damaged. The tire may still hold air, and the car may seem to drive normally, but the sidewall is no longer as strong as it should be. Unlike a simple tread puncture, a sidewall bubble can't be safely plugged or patched. Once the internal cords are damaged, replacement is the proper repair. A Hard Pothole Hit Can Damage the Tire From the Inside One of the most common causes of a sidewall bubble is hitting a pothole hard enough to pinch the tire between the wheel and the edge of the hole. The outside rubber can look almost untouched afterward. Inside the tire, however, impact force can break or weaken the reinforcing cords that give the sidewall its strength. Air pressure then pushes against the weakened area ... read more