Blue smoke is a sign of burning oil. It is likely, due simply to age, the valve guide seals are hardened and cracked. In addition, from sitting for that long they are likely dry-rotted. That will allow oil to run down the guides and into the cylinders where it is burned. Since it's a lot thicker than gasoline it will take a few minutes to completely burn off. Once the engine is warmed up the oil runs down the guides too slowly to cause noticeable smoke. At start-up that oil gets blown into the exhaust system where it takes longer to get hot enough to burn the oil off.
This smoke can also be caused by the engine oil being diluted with gas. I'm guessing you changed the oil already but there's always a couple of quarts that don't drain out. I've had a few cars that smoke at start-up for a few minutes. The problem always seemed to clear up after about two weeks.
On most engines the valve guide seals can be replaced without removing the cylinder heads and valves. There's a special compressed air hose that is attached to the spark plug hole, and that air keeps the valves closed so the springs can be removed. You can also stuff a piece of rope into the cylinder, then bring that piston close to top dead center. The rope will hold the valves closed, and can be pulled out when you're done.
Friday, September 6th, 2013 AT 11:36 AM