Well... coil noise can be reduced by dampening the pcb. Maby tightening or loseing the screws of the cooler slightly makes some difference... also screw the card in instead of using any brackets that came with the case and make sure that the card is well tightened to the case...
Apart from that, playing around with the voltages and clockfrequencies may help to, but usually without result.
If nothing helps... RMA i guess...
Good luck!
Cheers