If you can feel it at relatively low speed then it should be well visible visually if you hand spin it. You might be surprised how obvious it is. I have seen some pretty bad ones! You should be able to tell if it is the front or back I would think. Is this a low profile tire? Those pretty much self-destruct at the first pothole.

Mike

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra