Why does Intel Power Gadget fully freeze the system?
Solution 1:
I would uninstall Power Gadget fully then reinstall from a fresh download of 3.5.2.
I have it running successfully on an 2012 13" MBP i7 w/ 10.11 w/ no problems, as well as a 2015 15" MBP i7 w/ 10.13
Is everything else ok, e.g. Apple Diagnostics/Apple Hardware Test, SMC, etc.?