It might be as simple as a small "staple size" pin hole that is causing the problem (or something like a nail, screw, small piece of sheered metal). I'd take it to the dealer for them to have a look at.....if you need a plug/patch, it's not more than $20 - $30 I wouldn't imagine. Not 100% sure if they will replace the tire, but tey might fix it at no charge. Good Luck!