A tire bulge is a localized outward distortion that can indicate damaged or separated internal reinforcement.
A tire bulge is a localized outward distortion that can indicate damaged or separated internal reinforcement.
An impact can pinch the sidewall between the rim and a pothole or curb. Internal cords may break even when the outer rubber has only a small mark.
A shallow inward recess can be a normal body-ply splice feature. A localized outward swelling is more concerning. Never puncture or attempt to flatten it.
A confirmed bulge is not a cosmetic repair. Remove the tire from normal service and correct wheel, alignment or suspension damage before fitting the replacement.
What the finding means
An impact can pinch the sidewall between the rim and a pothole or curb. Internal cords may break even when the outer rubber has only a small mark.
A shallow inward recess can be a normal body-ply splice feature. A localized outward swelling is more concerning. Never puncture or attempt to flatten it.
Possible contributors
A visible pattern or measured condition is evidence, not proof of one component failure. Compare all tire positions and combine the tire findings with pressure, alignment, wheel-end and service-history data.
| Condition to consider | Role | Verification |
|---|---|---|
| Pothole or curb impact | Possible contributor | Verify with measurements and vehicle history |
| Operation with low pressure | Possible contributor | Verify with measurements and vehicle history |
| Overload | Possible contributor | Verify with measurements and vehicle history |
| Wheel-rim damage | Possible contributor | Verify with measurements and vehicle history |
| Internal separation or cord break | Possible contributor | Verify with measurements and vehicle history |
Workshop inspection procedure
- View the tire from several angles
- Compare with the paired tire and known construction features
- Inspect both sidewalls, bead and rim flange
- Check wheel runout and pressure loss
- Inspect steering and suspension after a significant impact
Pressure, tire position, measurements, photographs and vehicle condition should be recorded before correction. That evidence makes the recommendation understandable and supports future comparison.
Service decision and follow-up
A confirmed bulge is not a cosmetic repair. Remove the tire from normal service and correct wheel, alignment or suspension damage before fitting the replacement.
Inspect the opposite tire and the other axle before finalizing the recommendation. When corrective work is performed, set a verification point so the workshop can confirm that new wear is no longer progressing abnormally.
Tread depth does not override a bulge, exposed reinforcement, suspected separation, severe run-flat history or damage outside an approved repair procedure.
Frequently asked questions
Can a sidewall bulge be repaired?
A visible bulge can indicate internal cord damage. Remove the tire from service and follow the tire manufacturer procedure; do not treat it as a normal puncture repair.
Can impact damage exist without a visible bulge?
Yes. Internal damage may be present even when the exterior looks minor. Investigate the impact history, air loss, vibration and wheel damage.
Should the wheel also be inspected after an impact?
Yes. Check the rim, bead seat, runout and nearby suspension components when the impact was severe.
What should be recorded on the inspection report?
Record the damage location, tire position, visible condition and the recommendation to remove or further inspect the assembly.
Technical review edition · Published 17 July 2026.