If your chassis is NOT grounded to the wall outlet ground it will be floating above ground. With a VOM set to continuity, touch the chassis to the wall oulet "ground" and it should measure continuity showing it is indeed grounded. Removing a chassis ground might break a ground loop and sound good but it is deadly if you touch the unit's chassis, and any conductor to ground. If there is a fault in the system, the system is looking for a ground through YOU someday, and to earth. THAT is WHY the chassis has to be properly grounded at all times.
I would heavily advise to not let your chassis float ungrounded, and fix the ground loop.
I would heavily advise to not let your chassis float ungrounded, and fix the ground loop.