Strange noise when the engine is cold

Hi! My Grand Caravan '07 creates a really strange noise when the engine is cold. It's kind of whining noise, but not continuous. It sounds more like spring that is tensing and then releasing. It's pretty loud in the beginning, but after a few minutes the noise subsides and completely disappears. The noise is louder when I press the gas pedal. Do you have any idea what that can be?

could be incorrect oil weight

Not enough information. Open the hood and tell us where the noise is coming from...

Thanks for the reply Mutualrespect50. What does exactly "incorrect oil weight" means?

Thanks aleekat (http://www.automotiveforums.com/vbulletin/member.php?u=7252). I've tried to locate the noise before, but I'll try again.

Zack, do you use the weight of oil the manufacturer calls for such as 5w30 0r more likely 5w20. also the whine could be power steering related or alternator related. Use a long prybar or stethoscope and hold it to various items with the engine running and list with your ear touching the prybar.