Question Wobbly AIO and inconsistent CPU temps

[KittySushi]

Got my build up and running last night, and this morning I noticed some inconsistency in CPU temperatures.
On idle I get anywhere from 35-45C and under load I get anywhere from 55C to 65C.
While monitoring the temps, I touched the AIO heat sink and noticed it wasn’t completely flush to the CPU. The temps went instantly (while idle) to about 55C. I then pressed it firmly against the cpu and the idle temps went down to 28C.

I took apart everything, checked the components, remounted everything, and I’m getting the same solution.

I noticed the mount on the back of the motherboard is what is causing the wobble. It’s not completely flush.

Would some rubber washers between the backplate and the motherboard be a safe option? I noticed online that some Asus motherboards are thinner than others and it can cause this issue.

Asus Maximus XI MB
Intel i5 9600k
Corsair h150i Pro cooler

Thanks in advance for your replies!

 

[g-unit1111]

One thing about AIOs is that you should check and make sure that all of your connectors are hooked in and secure. Also make sure that your CPU cooler is completely screwed down. On AIOs if they're not properly screwed in, they can absolutely cause problems like that. If the mounting bracket is indeed the issue, I'd contact Corsair immediately and see if you can get a new mounting bracket or RMA your cooler. It's a pain but that should fix the issue.

 

[KittySushi]

One thing about AIOs is that you should check and make sure that all of your connectors are hooked in and secure. Also make sure that your CPU cooler is completely screwed down. On AIOs if they're not properly screwed in, they can absolutely cause problems like that. If the mounting bracket is indeed the issue, I'd contact Corsair immediately and see if you can get a new mounting bracket or RMA your cooler. It's a pain but that should fix the issue.

I tested it with another MB and it worked fine, though. I know it’s not the coolers fault.

 

[g-unit1111]

I tested it with another MB and it worked fine, though. I know it’s not the coolers fault.

If it's not the cooler then I would point to the motherboard as the next likely culprit. Have you updated your BIOS to the most recent version?

 

[KittySushi]

If it's not the cooler then I would point to the motherboard as the next likely culprit. Have you updated your BIOS to the most recent version?

Yes. The Bracket that mounts the cooler to the MB is loose. I don’t think updating the BiOs would solve that issue

 

[Karadjgne]

You are using the correct standoffs? The ones for amd and the ones for Intel are very slightly different. By about 1mm.

If the standoffs are correct, then the screws aren't seating all the way down into the backplate. Corsair had had this issue before, the motherboard is actually thinner and the screws stop at a certain point. 1mm Teflon washers from a hardware store is an easy fix between the backplate and mobo.

I've also seen ppl put the backplate on upside down which creates issues.

 

[g-unit1111]

You are using the correct standoffs? The ones for amd and the ones for Intel are very slightly different. By about 1mm.

If the standoffs are correct, then the screws aren't seating all the way down into the backplate. Corsair had had this issue before, the motherboard is actually thinner and the screws stop at a certain point. 1mm Teflon washers from a hardware store is an easy fix between the backplate and mobo.

I've also seen ppl put the backplate on upside down which creates issues.

Now that is a good point - going back to the standoff issue. If you take the motherboard entirely out, does the case have any pre-installed standoffs? If so get those removed ASAP. They could be causing a short somewhere.

 

[Karadjgne]

@g-unit1111
I think something got lost in translation here lol.
Op's pump is not seating fully tight to the cpu. If he puts pressure on it, temps go down.

There's several causes to this.
One is the motherboard is thinner, usually found on Gigabyte mobo's for some reason.
Two is the standoff screws that attach to the baseplate through the motherboard. There's usually 2x versions, amd and Intel, one is a mm longer than the other, if you get the wrong set installed, the pump is quite loose on the cpu.
Three is usually in Corsair mounts. The screws are only partially threaded, have an unthreaded shaft above. So when you screw in the standoffs, the screw stops before it gets tight. This is especially bad when combined with #1.

In this case, since the backplate is loose, it's either #1 or #3 that's the culprit. The best solution is to move the backplate further away with 1mm Teflon washers, this mimics a thicker mobo and puts more distance between the unthreaded shaft and the nut in the backplate. The front side of the standoff should now be tight to the motherboard with no play.

 

[g-unit1111]

@g-unit1111
I think something got lost in translation here lol.
Op's pump is not seating fully tight to the cpu. If he puts pressure on it, temps go down.

There's several causes to this.
One is the motherboard is thinner, usually found on Gigabyte mobo's for some reason.
Two is the standoff screws that attach to the baseplate through the motherboard. There's usually 2x versions, amd and Intel, one is a mm longer than the other, if you get the wrong set installed, the pump is quite loose on the cpu.

So you think it's possible that the mounting screws have got mixed up? Like using the AMD set instead of the Intel one? I can see how that would happen and that's something that definitely can happen very easily.

 

[Karadjgne]

If the pump is loose, but back plate it tight, then wrong standoffs.

If backplate is loose, the mobo is too thin and/or the standoffs are bottoming out, can only get so tight, backplate is on backwards or any combination of that.

Backplate -> mobo -> standoff -> pump bracket -> retainer screw head.

Standoff height has nothing to do with the pump being loose if the backplate isn't securely fastened by the standoffs. Standoff height only affects pump being loose if the backplate IS secure.