An expert can correct me if I'm wrong here, but white can mean moisture is being burned. I JUST went through this myself and what was going on was I had two cracked heads. When the engine was running there was enough pressure being built that exhaust gas was being pushed past the cracks and into the coolant, thus pressurizing the cooling system. Then when the engine was turned off all of that pressure has to go somewhere, so it slowly (overnight) leaked back through the cracks into the cylinders. So, in the morning I would have some while smoke at startup. Every morning. And more than what you'd expect for just ambient condensation in the air.
The quickest way to test is to make yourself a "hero" gage. Not sure why it is called that, but anyway... Get a liquid PSI gage, about 10 feet of hose, a T fitting, and three hose barb fittings. (Napa has all of this) Then disconnect the line that goes from your radiator to your degas bottle, and insert the t-fitting. Run the hose down by the driver's headlight and up to your cab. Now watch the gage as you drive around. If it climbs much more than 5 psi, you've got blown head gaskets, and possible cracked heads.
Last edited by Gus_hauler; 07-08-2013 at 06:26 AM.