Rx580 100% util. on loading screen.

[Mr.Sir]

I had just bought my Rx580 off of Ebay, claiming to be "New" and never used, I unpackaged it and it checked out, I plugged it in and noticed my temps were a little too high for idle, I continued and loaded a game and noticed the loading screens for almost every game would take up 100% of my GPU, and in return i would see 75 C on a loading screen. While in game it hovers around 76-79 and when it hits 80 it goes ballistic and ramps up its fan speeds and it gives me a black screen almost instantly. I had allowed and open flow test and the results were the same, i messed with the fan curve and it remained same, i would be willing to take a look inside the GPU once i have an alternative compound to spread onto the dye, (i ordered conductonaut). I have no idea what else it would be besides memory not being cooled properly, if you have any suggestions, i would greatly appreciate it. - Thanks