2010stanger

Hay guys!
I've noticed for a while that I'm getting a weird noise coming from tranny or engine area (middle of dash)while cruising in 5th gear. It almost sounds like if something is flopping In the wind/grind maybe something loose in tranny or engine but it only seems to make the noise in 5th can't hear it in the other gears. So it only makes noise when I first put it in 5 for about a minute and then noise is gone doesn't matter if engine is hot or cold. After its been in 5th and noise is gone I can change gear and go right back in 5 no noise! it only does it when I first put it in 5 after starting car!