GPU fan sometimes works and sometimes it doesn't?

[Morin0]

Lately my GPU has been overheating causing my computer to crash and I pinpointed the reason to be that the fan isn't spinning. However, what's weird is that it sometimes works cooling my GPU considerably, but sometimes it does nothing and my GPU heats up. Just now my GPU was at 112C when idling! Not playing games but idling! And then the fan kicked in and it cooled down. The fan stopped working and now it's getting hot again.

Replacing the fan is a last resort and getting a new GPU is an even more last resort. What can I try to fix this?

 

[Morin0]

Fixed it! The problem was that the GPU wasn't receiving enough power so that the fan can work properly. I connected the fan directly to the motherboard and the fan works now! Though my computer sounds like a jet engine now because it's constantly running at full speed (voltage?).

 

[John2k4]

It's probably running at full speed because the motherboard is not able to control it, and therefore is just feeding it the voltage it wants.