Bulge or bubble on the tire sidewall

Symptoms

• Visible bump or bubble on the side of the tire
• Bulge felt when running a hand over the sidewall
• Sometimes a slight vibration while driving
• History of hitting a pothole or curb recently

Likely causes

• CommonImpact damage from a pothole or curbA hard hit can break internal cords in the sidewall while the outer rubber stays intact, creating a weak spot that bulges under air pressure.
• PossibleTire aging and internal separationOlder tires can develop internal separation even without a specific impact.

What to do

1. Stop driving on the tire as soon as it's safe to pull over; do not continue on a bulging sidewall.
2. Inspect the bulge without pressing hard on it.
3. Check the spare tire's condition and pressure if you need to swap it in.
4. Replace the tire with the spare or have it towed to a shop rather than driving further.
5. Have a tire professional confirm the tire cannot be repaired; sidewall bulges are never patchable.

Tools and parts

• Jack and lug wrench if swapping to spare

When to call a pro

Have the tire replaced by a shop; a sidewall bulge always means the tire is unsafe and cannot be repaired.

Safety