My pc kept crashing and some of the reason was my PSU (q-tec 550W avoid!) but i still had some stability problems but not as severe as before.
Well i checked all my connections, whether everything was plugged in properly and the airflow.
Finally checked my Heatsink and fan, and what i found was where i could not install it properly because the lever it had to clip it down was in the way of the PSU so i turned the lever itself around 180 degrees but left the heatsink the right way.
Realised theres a dip in the center of the HS and turning the lever around meant the lever was not going in the dip so the clamping of the CPU core wasnt happening, realised i cant use the Heatsink with my case so bought a cheap coolermaster XP2200+ cooler and know it is solid as a rock.
My old HSF was the Coolermaster x-dream..