[Willit Stop]

Tires can develop flat spots if they sit for a long period of time. You can jack the front end off the floor about one inch and lay a piece of 2X4 on the floor and slide it till it just barely touches the tread near the center. If there is a flat spot,you'll see a gap when you spin the tire. The fix is easy. Go for a drive that's long enough to warm the tires. This may not be the problem but a possibility. Good luck.