white smoke blowing out of exhaust pipe
white smoke on 2003 Chevrolet Silverado 2500 HD
Light colored smoke out the exhaust is normal until the engine warms up, especially noticeable on cold mornings dense air. Blueish/gray smoke is a sign an engine is "burning oil", excessive black smoke would be a sign an engine is running to rich/too much fuel is entering the engine. White steam perhaps noticed with a slightly sweet odor from the exhaust, rough engine running, over heating and or coolant loss would be a sign of a blown or mildly blown head gasket.