2003 Ford Taurs, white smoke under hood, not over heating, no leaks...?

[squigit1985]

I have a 2003 Ford Taurus that has twice show poofs of white smoke coming out from under the hood, specifically out of the logo area, but the car is not overheating, and I took it to my mechanic, and we could find no leaks, the smoke does not appear to have a smell, and it is very intermittent, first time was Sunday morning and did not do it again until this morning (Wednesday) and it also only does it at idle, and for just a few seconds. No sounds of hissing (like water falling on hot metal or something). None of the wires anywhere appear to have any physical defects (there would be a burning smell if it were something electrical). Any advice would be greatly appreciated!
EDIT: Taurus, not Taurs

 

[timm]

maybe oil or some other fluid spilling onto hot exhaust or engine and the only reason you see it at idle is because of air movement when your rolling or if its coming out of grill area might be steam from radiator just throwing some ideas around monitor all fluids coolant oil washer fluid tranny power steering brake and if it starts using one of those you know where to look