So that means there are two sensors in the CPU. Either of the sensors is faulty or something went wrong when when applying the solder between the die and the heat spreader. Either way, cores 0 and 1 are more likely suffer from thermal throttling and overclocking won't yield the expected effects. In the latter case your CPU's lifetime could take a hit. There is no way to know which it is but Intel definitely messed something up in the production process.
With the age of that CPU you're probably out of warranty so it's up to you what to do with it. A broken CPU could possibly damage your mobo and some other components. You're going to have to replace both someday for whatever reason and you don't want your GPU or RAM to become the...