"Corsair H80 liquid cooling, 44C at idle, typing up this post it has gone up to 52C max"
"it lasted 2 minutes 30 seconds before locking up, temps had gone up to 62C by that time."
Are those core/package or socket temps? If core you are reaching the recommended maximum temp. Ether way they are much higher than I would exspect with the 80i
Are you using the LINK software? What is the 80i temp reported?
I would remount the 80i block/pump with new TIM to start with. How's the air flow in the case, you need good flow on the mosfet/vrm's. Many add a small fan to the backside at the MB cutout.
The 80i should give you 30-35C idle temps at stock clocks with the FX83xx-95xx cpu.
Core temp is displayed by a algorithm that is not accurate untill it reaches 35-40C, below that temp it display is much lower than acual temp and it changes rapidly.
The socket temp generaly runs about 10C higher than core temp.
Recommended max core is 62C and socket is 72C, these allow for a large safetynet. TJmax is 90C.
Speedbird: FX9590@5.2 CHVF-Z 8gb G Skill@2133 RAID0 SSD's RAID0 Raptors Crossfired R9 280X's Full EK loop dual D5's AQ6 Pro AX1200i
Goonybird: FX8350@4.6 GA990FXZ-UD3R3 16gb Corsair 1866 SSD HDD Sapphire 7970 OC CM Glacer 240L w/res Seasonic 850 Gold