A couple of months ago, my computer started making a rattling noise, as if something was shaking or a fan was hitting a wire. I open up my computer and find that my GPU was the cause of this. The fan was slightly loose and was shaking as it spun. I fixed it to the best of my ability and it stopped shaking for awhile. Now it is shaking again, but it won't stop. I tried to fix it and stop it from being loose, but it keeps shaking and making a rattling noise. It's not effecting my computer at all, but the sound is annoying and seems unsafe to leave it as is.

Any suggestions on how to fix this issue? I considered popping the fan off, but that would be a horrible idea because it would overheat (due to my lack of cooling systems).