my gmc sierra is blowing alot of white smoke just about as much as a diesel when it blows black smoke it goes on for 20min if not longer....sometimes within that 20min its a little bit then alot...

what could this be plus l live in nothern ohio so its cold and l dont know if it does it when its warm becuase l bought it in october...

my engine is a 5.3l v8 with 96000 miles

whats the temp. outside? does the smoke change with temp? how are the coolant and oil levels?

bad head gaskett

try smelling the smoke you see most likely its just cold but could be injetor bad or turbo going bad

Check your spark plugs..
Do you have a cylinder misfiring ?
You could have bad rings, bad valve seals, leaking head gasket ,
bad oxygen sensor or a fuel problem ( rich / lean ).

l am betting that it is just condensation issue caused by the warm exhaust air versus the cold climate.

Just like any other vehicle, it will blow white smoke, and it will reduce as the motor warms up. Keep an eye on your oil and coolant for possible contamination of fluids (hinting of a bad head gasket), but l highly doubt that it the problem.

I've had my truck never stop blowing white in -20*F.