CPU overheating A1286

[Neil250]

A1286, 2011 MBP 15"

Boots fine.
Can work for 1-2 hrs, sometimes longer.
Then CPU starts to overheat --> 70C on hardware monitor

A was looking for ASD 3S144 but I could not find it anywhere (I can use Google but the download sites listed are all down or expired)

I tried booting with D held down and then running ASD. It starts but freezes 10-15 minutes in.

Is there a common suspect sensor on these boards.?

 

[2informaticos]

70 degrees is not much at all.
More likely GPU problem.
Switch to iGPU with gfxcardstatus and check if machine stays on more time.
Completely disable GPU (fastest way in BIOS) and check again.