I think it is going bad. I had this problem on another vehicle. The car sounds like a plane taking off and it started all of a sudden after the car had trouble getting into reverse. It is switching gears okay with no slips.
Can the torque converter be unplugged and if so where is the plug? on 2004 Kia Sedona
No, you cannot unplug the torque converter you need to have this checked at a transmission shop.