Question 90°C in BIOS 1 month after reapplying thermal paste

[odaaN]

I bought my pc in 2020, and completely forgot to change my thermal paste. It worked completely fine up until the middle of October this year, when the temperature suddenly got up massively, 100°C on desktop and 95 in BIOS.
I reapplied the thermal paste on the 23rd of October and cleaned the pc and it resolved the issue, everything was completely fine.
Yesterday, my pc was working normally, but today out of nowhere the issue came back, 90°C in BIOS, and I have no idea why.
Is it a thermal paste quality problem? A cooler problem? But if it is a cooler problem why is it doing 90°C in BIOS? Even a pc without a cooler shouldn’t be doing 90°C in BIOS, right?

PC:
Water Cooler Corsair Hydro Series H80i V2 120mm
Intel Core i9 9900KF
1 fan

 

[rgd1101]

water cooler is working?

 

[odaaN]

water cooler is working?

Seems like it’s working. But even if it wasn’t, a pc without a cooler shouldn’t be doing 90°C in BIOS, i believe.

 

[uWebb429]

Even a pc without a cooler shouldn’t be doing 90°C in BIOS, right?

You under estimate how much heat a CPU can put out. Many motherboards disable the low power C states when you are in the BIOS. A CPU can easily run at full temperature when a heatsink is not installed or if an AIO pump is plugged up or has failed. Feel both hoses going to the AIO. One should be hot and one should be cool.

Check and try replacing the thermal paste again. If you do not see any problems with the thermal paste then you need to replace the cooler.

 

[odaaN]

Check and try replacing the thermal paste again. If you do not see any problems with the thermal paste then you need to replace the cooler.

Ok, thanks. I’ll replace it tomorrow and see if it solves it.

EDIT: I have absolutely no ideia why, but the issue resolved itself (?). I tried once more to start my pc before reapplying thermal paste and the temperature was normal again.

 

[SkyNetRising]

Feel both hoses going to the AIO. One should be hot and one should be cool.

Actually - if one hose is hot and other cold (you can feel temperature difference),
this means either pump has failed or cpu block clogged.

Replace AIO.