Hey Guys- Maybe you can steer me in the right direction-

I have a 2004 BMW X5 4.4i (Production 4/04) So im assuming its the N62 engine- The car is tight- and rides phenomenal like my E39 Sport.
The other day this is what I began noticing-

Coming to a stop (i.e. Rail Road crossings- car parked and running- ) and then progressing to normal road speed I would see grey smoke? white smoke? nothing to dark- emit from the exhaust of the car only for about a couple seconds- then driving the car would be fine- the Temperature gauge is spot on in the middle- ive looked under the car and have not seen any oil spots-

Could it be valve cover gaskets? The X5 currently has 120k on the clock- mostly high way miles. I am here in Kansas City- So the only dealership is Baron BMW- and i don't want to deal with them- I have a great parts source for german cars- I just want to know what I should do- or expect-

Thanks