my old ladies sorrento has AC that makes the cold smokeHold a cold mirror (stick it in the refrigerator for a while) up to the "smoke" stream, if it's steam, it will condense into water on the cold mirror. Then look at your head or intake manifold gasket(s).
I second the "you need a different "mechanic" statement, regardless.
We installed a Vintage Air system on a camaro here in Phx,az. The customer drove it to California on vacation, and complained about "smoke" coming from the A/C vents, it was fog from the COLD air conditioner!