Unlocking cores disables the cpu temp readings.
Usually you will only get one overall temp on an unlocked cpu, on Coretemp you get none, just usage %
Try HWmonitor, Speedfan and OCCT, they will pick up temps, run OCCT with these progs open and you will see 1 or 2 of the temps fly up, these are your cpu temps.
Also if you run OCCT for 1 hr it will test the stability of your unlock.