I have an '05 Sierra Diesel that has 118,000 miles on it and blows alot of white smoke while I am in idle. I'm away from home on work so I can't take the truck to my trusted mechanic. Any advice from anybody with experience in this matter would be great.

 

are we talking a small buildup of smoke or a freight train?

how white?..grayish,or thick and white?./...pure white =coolant,which is never good.
is it low of coolant?
your bullydog programmer may have busted a headgasket.