Originally Posted by jskadberg
My 2005 5 speed Insight suddenly developed a vibration on the freeway that seemed like a bad tire. I rotated tires and that did not make any difference. I drove about 100 miles home and it did not get any worse. Vibration starts at about 20 MPH and continues on up.
Have you tested whether it occurs both in gear and in neutral, and maybe other circumstances (like more or less under load)? If it happens whether in gear or not, it's less likely to be engine-related / most likely axles on out to the wheels... Rotating the tires wouldn't necessarily eliminate the tires or wheels as suspect, as all the same wheels remain on the car. Could be you lost a balancing weight on one of the wheels? I think I'd take it in to a tire shop and ask them to check the tires for damage and the wheels for balance. If you bought the tires new from a particular place they might do that for free, I know my shop would...