Hello, hooked up a Hampton Bay- Transitional Collection- Winston 52" and it worked fine after a couple of hours. After that it started making a rasping noise and the ceiling fan slow down a little, once I turned the light off. I connected the black and blue to black and white to white and green to green. Did I do something wrong or did a make a bad purchase?

Sounds like you connected correctly.
With fan off, spin blade by hand, Any Binding?

I checked, no binding. The ceiling fan does not make noise when the light is on, it runs smooth and is quiet. It makes the noise when I turn the light off and the ceiling fan does slows down when the light is off also. I even took the ceiling fan down again and checked to make sure the wiring was tight, it all seemed well. Should I try something else?

Check loose white wire in switch housing of fan(fan white, light white, and supply white).

Confirm all the screws are tight, and any glassware, and if the noise persists, take it back to the store. You could fix it, but you have a new fan, so you shouldn't have to.

General ceiling fan troubleshooting and help FAQ- Ceiling Fans N More