Ok, every morning and afternoon this week when I have started my engine, my truck makes a weird whining noise. It only lasts about 1 - 2 seconds but sounds much like a supercharger whine. If only it was a supercharger whine!

Anyway, not sure what this could be but makes me worry that maybe it's engine related. I thought it could be the power steering pump, but the fluid is good, it works fine, and doesn't leak. I don't have AC, so you can rule that out. Can anyone offer some insight?
Thanks, Scott