I7 6700k idling at 100c

[dillonc.24rules]

I've had my computer(custom built) for about a year now and I just started having problems where my cpu would sorry start rising in temps all the way to 100c while just idling. I have an H100i v2 aio water cooler so it should never get anywhere near that high. This isn't the first time its happened in the past month and I've tried what's below to fix it each time, only to get it to run until the next week and start overheating again, leaving me clueless as to what's happening.

What I've tried:
-reapplying thermal paste
-tightening the screws on the heatsink
-cleaned out any sign of dust

I am officially out of ideas, so any help is appreciated.

My specs:
mb-gigabyte ga-z170x
Cpu-I7 6700k
Gpu-Nvidia 970 gtx

I am happy to provide any details or pictures of anything that I may have forgotten or any that might help the situation.

I really don't want to have a 300$ CPU that its only use is frying eggs.

 

[dillonc.24rules]

Edit: I unplugged some of the aio's wires from the motherboard and put them in a different place. Apparently the pump was not working but is now?

 

[baha_timimi]

Idling for 100 C may be mean incorrect reading software. Do you try reformat the system ?
When CPU reach this temp. it must burn and fail.

 

[geofelt]

At idle, your temperatures should be about 10-15c. over ambient.
Likely, there is something wrong with your cooler.
Perhaps the pump has clogged.
Perhaps a fan is not turning.

If your cpu detects a dangerous temperature, it will shut down to prevent damage.
That is around 100c.