rumbling noise on 2006 Dodge Magnum

When I turn on the A/C the car makes a rumbling noise and also when the car is out of park with my feet on the brake the car does the same thing I haven't been cutting on the A/C lately and now when I sit at a idle the car does the same rumbling noise what can be wrong have anyone had this problem before or have any advice.

Asked by for the 2006 Dodge Magnum