Any chance you're mistaken on what the existing processor is?
As suggested by Suman_1978, swap CPU's and see if the problem follows a certain slot or CPU, and that's also a good way to double-check and make sure both processors are seated properly.
As suggested by Suman_1978, swap CPU's and see if the problem follows a certain slot or CPU, and that's also a good way to double-check and make sure both processors are seated properly.