So while towing a 6 horse trailer with an 06 6.0 powerstroke, blew a belt idler. Belt went, lost power steering, heated up. Pulled over (still running quietly) , shut down, and determined teh problem. Truck towed to local dealer, and idler fixed, belt replaced. Truck now emitting white smoke, and serviceman is concerned (me too). It ran maybe 1 or 2 minutes after belt let go. How quick before major damage starts? Temp needle went up in a hurry.