If you have overclocked the CPU consider turning the clocks down a bit.
i5 6400 dont think i can oc it
Well those temperatures are safe considering this was a stress test, what program did you use use for the test?
I would be concerned if those we're the temperatures during gaming.
That's not the most intensive stress tester, I'd consider anything over 85c hot when testing with that. You should try re-applying thermal paste, clean out any dust in your CPU fan to make sure it runs best.
AIDA64 has 15 possible stability tests involving the processor, any of which, selected either individually or in combinations, will produce different Core temperatures due to workloads that range from less than 70% to more than 115%: