My 07 Expedition has been blowing blue smoke on start up after it has sat for some time IE overnight or a few days, I know enough about engines to know what that means and whats causing it, has anyone else heard of or had this problem with their engine? Mine has just under 30K and I have change the oil by Ford per their recommendation.

 

your still under warranty take it in. Make ford fix it. might have a bad valve guide..

 

I agree,,,, Smoke at start-up is usually a bad valve guide.......