[mikeymoman]

I have a 2006 Xterra that runs very well. Lately I've noticed this sound when I start the engine. It only lasts for a few seconds but has me concerned that something is on it's way to breaking. I know one of y'all have heard this and figured out what it is. Please Help! Thanks!
www.youtube.com/watch?v=LNkKNWq69QY