2008 Acura TL 2008 Acura TL Start Up Noises

Hi,

My 2008 Acura TL lately started to make grinding noises when first start up in the morning. It lasts a few seconds to a minute. It dies down once car is on the road. This noise is not there when I start the car for the rest of the day. But it happens almost every morning after a night's rest. I took it to dealer, and they told me something about the belt, it was loose and they replaced it. But a few days later, it started to make the noises again and now - every morning.

Any advise you have for me? Thanks so much!