Although Intel's Core i processors are capable of operating above 90C, we also know that excessive heat kills electronics. As common sense and experience usually prevail, most folks in the Intel overclocking community will agree that sustained Core temperatures greater than 80C is too hot for stable gaming or processor longevity.
Temperatures greater than 80C are typical during 100% workloads such as Stability tests or Thermal tests, however, temperatures are considerably lower during real-world everyday workloads such as video encoding, processor intensive applications or gaming.
So something is just not right.
I would remove the cooler, clean the cooler and CPU, and reinstall the cooler with fresh thermal paste, paying particular attention to the locking pins on the cooler to be sure that all 4 are securely locked to the mobo.
Ah, I asked my older brother about this and he knew something about it, so he went in the BIOS and he... I think enabled EIST... but disabled something else that said frequency something something. And now I tried rendering for 5 mins, and my temps barley reached 74c under full load! And it stayed at 3.4