I am not sure if this is a big deal or not. This ram is a 19' with 1986 miles. I started it up today after having sat for several hours in about 50 degree weather on the driveway and a small cloud of blue smoke came out of the rear exhaust. I would expect older trucks to do this from time to time as valve seals age. My chevy does this occasionally. Is this something any of y'all would bother taking in to the dealership ? Again, I have only seen it happen once but I wasn't looking for it until now. what do y'all think ? Big deal or not ?