2004 Acura MDX Steering Wheel Vibration - Sometimes

Hi,



My fiance has a used 2004 Acura MDX with around 60,000 miles. When traveling at high speeds (over 65 mph), the steering wheel sometimes will vibrate left to right. The odd part is that it only occurs some of the time. Going around a turn will sometimes make the vibrations quit, and sometimes not.



I was thinking that maybe it was a problem with the tires, but a rotation did not fix the problem. It is due for new tires, but I think that it is something else.



Any ideas what could be the problem?



Thanks!!!