I5-3570k temp concern

[Waterfire]

System -
I5-3570k(Stock speed)
Asrock Z77 Extreme 4
Cooler Master Hyper 212+ EVO(2x 120mm fans in push/pull config)
8GB G.Skill Ripjaw DDR3 1600
EVGA 560ti FTW edition
Samung 830 128GB
WD 1TB - forgot which model
PC Power and Cooling 750w(overkill I know)
Corsair 400r case(2x 120mm fans in front, 1x 120mm exhaust in back)
Windows 8 - cheap and with Classic Shell it's easier to use.

Now the problem - CPUID Hardware Monitor is showing higher temps than I think I should be getting. The temps fluctuate a great deal down to low 30s and back up to nearly 40C within seconds. Not sure if this is normal.
Core 0 - 39C
Core 1 - 39C
Core 2 - 33C
Core 3 - 32c
Package 39c

under prime95 the temps jump to upper 60s/low 70s. I tried to overclock slightly to 4ghz and prime95 took the temps into the low 90s.

I am thinking I may need to reseat the heatsink, but I wanted your opinions. The hyper 212+ can be a pain to install. or Maybe I used too much thermal paste.

*edit*
I forgot to mention my ambient room temp is about 78f(25C, if I did the math right)

[noteworthynerd]

Temperature fluctuations are normal, especially at temps as low as that... Unless they are going 90C+, you're fine.

That being said, if you weren't able to overclock to 4GHz with that cooler, you may have messed up the thermal paste application. The "pea" or "bee-bee" method has been proven to be the best, just a pea sized dot of TIM on the middle of the CPU then apply the cooler.

[Waterfire]

thanks, looks like tomorrow I get to have a wonderfully annoying Hyper 212+ re-installation.

---------- Post added 2012-12-03 at 10:40 AM ----------

Did the re-installation. Here's a pic. The max temps are under 100% load(stock speed). The idle temps are much better, but the 100% load temps are still high(at least I think).
i.imgur.com/tTQ7H.jpg

Can't post links yet.

---------- Post added 2012-12-03 at 10:52 AM ----------

Tried to OC to 4Ghz like before. Now the cpu reaches almost 100c. So, i quickly shutoff the test and reverted back to stock.