What's going on with my FX 6300?

[Mr.Scott]

Under the center of the cooler, there is a small knurled thumb screw. Make sure that is tightened all the way down when you do your remount.
Don't dot the paste, spread it to cover the whole IHS. Trust me.
It doesn't have to be thick either.

 

[caddi daddi]

this^^^^^^^^^.

and you need to make sure that both fans are blowing to the rear of the case.