[Capri306]

I tell you what, dude, that usually means only one thing: coolant is entering the combustion chambers somehow. Pull and read your spark plugs, they'll tell you which cylinder(s) bit the dust. After that, a compression test could be in order, as well as inspecting the condition of the coolant. Possible causes are ususally head gasket failure, cracked heads, cracked block, or I've also seen a leaking EGR spacer gasket (after all, there IS coolant going through that spacer, right?)

Remember, this is if it's WHITE smoke, NOT blue. Good luck.