Question Sudden spike to "100" degrees on all CPU cores

[Parasite03]

Hi everyone! Recently my computer started to abruptly shut down.
ASUS B85M-G MB, Intel Core i5-4690, NVIDIA GeForce GTX 760
So to diagnose this I used Open Hardware Monitor to record stats and this is what I found:
Google Drive Picture
The columns are Core 1, 2, 3, 4 and Total
As you can see, it's going okay and right before the crash the temperatures spike up by about 20-40 degrees, and then flat out at exactly 100. This does not seem very probable.
Anyone got any ideas tow hat this is?

 

[mdd1963]

What is your actual cooler solution?

Factory cooler? See if it is still locked down/secured to the heat spreader...

IF you can carefully remove the cooler (with power removed from PSU!), cleaning heat spreader and top of CPU's heat spreader, perhaps a fresh light/thin application of thermal compound might help, as sometimes some thermal compound solutions dry out/become ineffective after 5-7 years....

 

[Parasite03]

What is your actual cooler solution?

Factory cooler? See if it is still locked down/secured to the heat spreader...

IF you can carefully remove the cooler (with power removed from PSU!), cleaning heat spreader and top of CPU's heat spreader, perhaps a fresh light/thin application of thermal compound might help, as sometimes some thermal compound solutions dry out/become ineffective after 5-7 years....

Okay, so I haven't had time to take off the cooler yet, but:

• The cooler is some Master Cooler heatsink + fan.
• The thing is.... After it powered off again I turned off the PSU and opened the case and tried touching everything I could (PSU, MB, CPU heatsink), nothing was hot, only slight warm.

Also, when I powered on the PC again BIOS reported +35% on the CPU...

So I'm not really sure if this is even a hardware issue.