4790k hitting 100 C while gaming, and shutting down computer

[blacktrance]

I've had my current computer for about a year and a half now, and until recently it worked fine. However, I moved recently, which may have bumped something, because now when I game it sometimes hits temperatures of 100 C, and shuts down my computer. Usually it restarts and runs normally afterward, but today it restarted and told me that the CPU temperature was too high (the BIOS told me it was 88 C). After waiting, it turned on normally and is now displaying temperatures around 40-50 C in Open Hardware Monitor at idle.
I use the stock cooler, and its fan seems to be running fine. As far as I can tell, nothing has been disconnected.

 

[TJ Hooker]

Probably need to clean heat sink fins/fans and/or re-apply thermal paste. Getting an aftermarket cooler probably wouldn't be a bad idea, although not strictly necessary.

 

[Nuckles_56]

My guess is that during transport, you managed to bump the CPU cooler out of position, thus the cooler isn't making proper contact with the CPU, so re thermal pasting it will do the trick

 

[utroz]

You need to open the case and make sure everything is still correctly installed. Your cpu cooler could have become loose or the fan could be unplugged, or something could be in the way of the fan causing it to not spin, or one of the pin things that hold the cooler down could have popped up making the cooler contact loose. Something is not right at all. I would get some decent thermal paste and take the cooler off and clean the old thermal paste off and put new stuff on and then check your cpu temps under load. Also I am kinda surprised that you are using a stock cooler for a 4790K as it is a overclocking cpu where you usually use an aftermarket cooler and get 500Mhz for free without much fuss at all.

 

[blacktrance]

I've opened up my case and the CPU fan is definitely still spinning. I'll take another look at whether the cooler has gotten loose, though I don't think that it has.

My CPU is not overclocked.

 

[blacktrance]

Also, if I was going to reapply thermal paste, would I need to remove the motherboard from my case to remove the cooler?

 

[utroz]

Also, if I was going to reapply thermal paste, would I need to remove the motherboard from my case to remove the cooler?

No you shouldn't have to remove the motherboard to remove the heatsink to reapply thermal paste. I would set the case on the side when doing this to make it easier to remove and reinstall the heatsink.