Blue smoke is a sign of oil burning. Are you sure it is not white? Cold engines always show white 'smoke' which is steam, due to the system being cold. This will stop as the system warms up.If the engine is not using much oil,there is nothing to worry about. Could be a bit of oil seeping down the valve guides when the engine is at rest.Rather depends on the condition of the engine.
davidj, July 2011