Very odd temperature spike, 147C

[Dellius]

Yesterday, while I was trying to OC my i7, I suddenly got a very odd temperature spike, right out of the blue. I restarted immediately so I didn't take a screenshot, as I was really concerned not to break anything.

Story
I tried to OC my i7 to 4GHz, but I never made it there, in fact my best speed is only 3.61GHz right now, as the problem appeared at 3.63GHz so I keep it just a bit under that and it runs fine, for now. Before that the CPU ran all day very well at 3.63, passed all stress tests, and temps never went above 60C. When I tried to reach the 3.8GHz mark, things started getting a bit odd, blue screens and all, so I lowered the frequency back to the last stable position at 3.63GHz, and suddenly the fans went really loud and when I booted into Windows and checked the readings on the Intel Desktop Control Center, all temps were between 39 and 43C, except for the CPU temp, which was at 147C. I couldn't believe my eyes, so I rebooted, reset all settings in the BIOS to defaults, rebooted again, the problem was gone, so I tried to clock it back to back to 3.6, and now it's running well and stable at 3.61. I even played Sniper Elite v2 on ULTRA and temps never went above 53C. I have no explanation as to what might have caused the issue.

System specs
i7 920 @ 2.67GHz Revision C0/C1, Stepping 4, OC to 3.61GHz at the moment.
DX58SO, latest BIOS build, updated yesterday.
vCore voltage at the time of the accident was fluctuating between 1.22 and 1.25, and they actually fluctuate like this even now, with no issue.

The system is very well cooled, with 12 very powerful fans, and the CPU is with a very strong air cooling, but I have to go home and open the box to tell you the exact models of the cooling, fans, and PSU.

I am not sure what caused this, and isn't the system supposed to shut down at such high temps anyway ? I didn't really disable the protections in the BIOS.

[901-Memphis]

If its set up in the BIOS correctly it SHOULD shut down after a certain temp... like 100C or what ever you set it to. It would be weird though to spike from such a stable temp to so high with minor overclocking. I wonder what model that heatsink is.

[Jahova]

I'll bet it was a glitch. I've seen negative temp glitches before. At over 110*C just about any thermal paste will begin to burn up.

Ever seen what happens to an Intel CPU after it cooks? The thermal paste cooks and chars the heat sink and CPU contact surfaces. Upon dis-assembly, you would see pitting and black char. It almost always fries the motherboard.