I recently did the 2080super hybrid pmw fan mod to voltage control to reduce the noise. Installed fine but My temps skyrocket under any sort of load. Like a video for example. I sit idle at 35c ish and as soon as load starts, its to 80c within a couple minutes. I understand theres a lot of factors that could go into this but if i switch back to auto mode from Voltage control then all is well. But of course, annoying sound is back.
 
Probably should add some system specs and more info.
Gigabyte Aurus gaming 7
2080 super hybrid ftw3
8600k
Also, the problem is intermittent. I can restart and the problem goes away. But ive noticed that when i boot and my idle temps are high 30's then the problems going to happend. When my idles are sub 30 then im good to go.

That could mean your pump is actually not working, voltage is too low. 
Without water circulation gpu will overheat very fast indeed.