TO the OP,
Mine used to do it all the time it will be much more noticeable when cold outside. Ever since I did the transmission fluid change with Redline C+ ATF the noise is gone. At about 10,000 miles I did a pan drop/fluid change and changed the filters. Also installed. 2+ quart deep pan. Did it well befor the beginning of this winter....( still winter here) and have not had the noise all winter.
After the first fluid and filter change i did 2 more fluid changes (left the filters) to achieve as clost to 100% Redlin C+ ATF in the transmission as i could. I did all 3 changes within a few months of the first one.
Not sure if its related but seems lile it could be. I had it ALL the time and now nothing.