so part of my job includes rebuilding trucks that are complete writeoff's and recently we rebuilt an 06 sierra 2500hd 6.6l 4x4..the truck was written off in 06 with only 15 thousand miles on it..but wasnt insured properly and ended up sitting in a field under a tarp for the last 4 year's..what happened was the owner of the truck lent it to his buddy and his buddy fell asleep hit a telephone pole and rolled down a 100 foot hill..now to the question..the truck smokes quite abit under acceleration blue smoke not black..it wasnt hydraulliced when we got it but i pulled the glowplug's just incase..seeing as the airfilter was soaked in oil..i'm just wondering if the smoke is from residual oil in the exhaust or if its an engine issue..the truck runs smooth and drives nice thou..here are some pictures of when we got it..

 

wow! thats a mess, i would run it for a while and see what happens, it cant really hurt anything, it will probably clean up after a getting a little run time

 

If the air filter was soaked with oil, then the rest of the intake track may be as well. I would especially check the CAC. If it is full of oil, it may take a long time to get the oil out of it by just running it, plus if it is too full of oil it could cause the engine to "run away" by feeding off the oil in the CAC.