You have a bad wheel bearing. If it goes away when you turn left, the vehicle's weight shifts to the right side. As a result, the weight is reduced on the left allowing the bearing to quiet down. It is possible not to have play and one still be bad. Can you tell if it is coming from the front or rear? If you can, replace that bearing on the left side.
Let me know what you find.
Joe
Monday, November 2nd, 2009 AT 7:30 PM