I had same issue... First thing I did, check coolant and oil for mixture (if that's the case usually means cylinder head gasket)... If that's not the issue monitor the exhaust to find out exactly when it blows smoke (eg. Cold starts, cruising down a hill, or on hard acceleration).
Once you've done that you could probably post your results and we'll help ya some more
PS: from what I've heard if its your piston rings the thing just blows white smoke constantly and unbearably... I blew the rear seal on my turbo and everything was running fine - it would just burn oil in the mornings!