Question Can someone help me figure out why my CPU is suddenly running so hot?

Jun 18, 2025
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A week ago I heard my fans making some odd noise, but they seemed to fix themselves. The other day I restarted my PC after installing some updates, then went to bed. When I woke up, the screen displayed a temperature warning and I went through BIOS to adjust the fan speed.

I cleared the fans of any dust with compressed air, cleaned the CPU and Cooling Plate and replaced the Thermal Paste.

When I booted it up the CPU was running around 45c, but when running a single game it reached temperatures of up to 90c, with all 9 fans running.

When I did a test using Armory Crate, at lower rpm the system performed an emergency shut-down.

I thought that perhaps I had made a mistake with the thermal paste, so I cleaned it up and reapplied, this time not bothering to use a stencil.

Now it can't stay on windows for more than a few minutes without shutting down automatically, like a 'Quickdraw' BattleMech. I felt the coolant tubes earlier and the lower one was hot and the upper one cool, and despite the lights the top fans are working.

I can't seem to increase the speed any more, and I noticed that the air coming out of the heat-sink is cool, not hot...

I don't know what to do now. I feel like I messed up, but don't know exactly how. Just a week ago everything seemed fine, and now I've gone through a decent amount of Thermal Paste, Q-Tips, Alcohol Wipes and Paper Towels and my lower back is killing me.

Anyone have any advice?
 
@Storm Mollusk

What cooler do you have? Some AIO coolers can become clogged up internally over time. Temperatures will go up and up when that happens. Some of the MSI MAG CoreLiquid series needed to be recalled because of this problem.

If you have a decent air cooler available, try installing that.

after installing some updates
If there was a recent BIOS update installed, that might have increased the CPU voltage or changed some other setting. That can cause a CPU to heat up more than what it used to. You really have to keep a close eye on the updates that are supposedly good for your computer.
 
I have a Lian Li Galahad AIO.

I don't have a good alternative, unfortunately.

If I did install a 'bad' update, I'm
not sure how to be certain, or what to do about it.

All the other components are at decent temperatures, but the CPU heats up as though I just dunked it in magma and it refuses to cool off.

It's worse now, after reapplying the heat-paste, but I don't think it necessarily has anything to do with that.

Now, even with no programs running Core Temp says the cores are under heavy load, which it wasn't showing before. I let it sit with fans on full and it just slowly got worse until it shut down again.
 
@Storm Mollusk

What cooler do you have? Some AIO coolers can become clogged up internally over time. Temperatures will go up and up when that happens. Some of the MSI MAG CoreLiquid series needed to be recalled because of this problem.

If you have a decent air cooler available, try installing that.


If there was a recent BIOS update installed, that might have increased the CPU voltage or changed some other setting. That can cause a CPU to heat up more than what it used to. You really have to keep a close eye on the updates that are supposedly good for your computer.
I have BIOS version 1720 x64
 
Agree with the others that something bad has happened with the AIO, such as the pump failing. The delta between the liquid coming from the CPU and the liquid leaving the radiator is only a degree or two of celsius, so the fact that you can feel the difference is quite good evidence that the cooling process is fundamentally broken.