Chrysler Repair: 98 Sebring Convt 2.5L: engine clatter at start-up

Question
My Sebring makes a loud clattering noise when started cold and belt makes noise also. When warm noise fades but when a/c is engaged it returns. Sometimes it will make the noise when idling but only briefly. When cold and started you would swear it's a main or rod bearing but I know it's not especially considering that it quiets down a bit after warm up.Any idea what this could be? Hard to locate source by just listening.A/C clutch bearing, water pump, harmonic balancer etc.?

Answer
Hi Norm,
It is difficult to know without hearing it in person. But clattering does suggest valve train noise perhaps due to the oil pressure not being sufficient to stiffen the hydraulic valve lifters. Is it possible that you are using too thin a grade of oil or that changing the oil to the next higher number would increase the oil pressure at low rpm so as to circumvent that sort of a problem? The A.C. relationship may simply be a decrease in rpm in response to the added load of the compressor. What does the oil pressure gauge read and does than seem to be  related to when the noise occurs? That is my suggestion based upon being at a distance.
Please read the PS (below) and respond to it.
Thanks,
Roland