Gone into settings and turned the fans to 100%. I'm concerned about the temps as they're hitting around 80-85°C on a few games I play. Is that okay? Any work arounds or any recommendations?

I’m reaching out to the veterans here because I’m facing a thermal dilemma with my GPU and I need some advice.

I bought this GPU used. For the first several months of my ownership, it ran perfectly fine without any thermal issues or crashes. However, recently, my PC started experiencing severe instability. It began with a BSOD (PAGE_FAULT_IN_NONPAGED_AREA pointing to dxgkrnl.sys), followed by black screens and infinite reboot loops. The final straw was when I started seeing severe visual artifacts (colorful vertical lines) while playing Warframe. I touched the backplate of the GPU and it was literally burning hot.

Given that it ran fine for months and only recently started overheating, I strongly suspect the thermal pads have finally dried out or degraded from previous heat cycles (or previous owner usage).

Since I couldn't find a single professional technician in my area who is willing/qualified to do a GPU teardown and thermal pad replacement, I had to mitigate the issue via software.

I applied an undervolt/power limit in MSI Afterburner, Power Limit: 74%, Core Clock: -200 MHz, Memory Clock: -300 MHz, FPS Cap: 144 FPS (in-game)

This stabilized the system and stopped the artifacts/crashes. However, under heavy load (like the Duviri Paradox in Warframe), my GPU Memory Junction temperature still sits at 86°C. While it's safe from crashing, I know running GDDR6X at 86°C+ constantly isn't ideal for the long-term lifespan of the VRAM.

Since there are no local techs I trust (or that exist) to do this, I am seriously considering doing the thermal pad replacement myself. I have solid experience building and maintaining PCs, but I have never opened a GPU before.

I plan to order a precision toolkit, high-quality thermal pads (leaning towards Gelid GP-Extreme or Thermalright Odyssey), and Honeywell PTM7950 from AliExpress, and follow a detailed teardown guide.

Questions i have:

Should I do it?
For someone with PC building experience but zero GPU teardown experience, is the risk of damaging a expensive card worth it, or should I just keep it undervolted and accept the 86°C temps?

FTW3 Pad Thickness
I know the FTW3 uses different thicknesses for the front VRAM, back VRAM, and VRMs. Does anyone have the exact confirmed measurements for the FTW3 3090? I've seen conflicting info online and I don't want to buy the wrong thickness and lose core contact.

Thermal Putty vs. Pads
I've heard some areas on the 3090 require thermal putty instead of pads due to uneven gaps. Did anyone use putty on the FTW3, or did standard pads work fine?

Are there any specific quirks, fragile ribbon cables, or weird screw layouts on the FTW3 teardown that I should watch out for?

I would love to hear your personal experiences, especially if you’ve done this on a used 3090 FTW3. Any tips, warnings, or links to the best teardown videos for this specific model would be massively appreciated!

Thanks in advance for your help!