Weird fan noise problem

[Deleted]

Hello!

I have a really weird problem with my case fans that has been going on for quite a long time. They randomly start making A LOT of noise that sounds like a propeller. I really don't know how to explain it better!

The problems and things I checked:
-It's not a heat issue, I monitor temps and it also happens when nothing is running. Neither the cpu or gpu is overheating.
-I've replaced every single fan in my system over the last year with better quality/quiter ones. The problem didn't stop.
-It's not a cable getting in the fans issue.
-It's completely utterly random. I can't replicate the problem by putting the system under load.
-Fans RPM both during the problem and before do not go up (or down for that matter).
-It doesn't originate from one single source. Originally I thought it came from the CPU fan, but the last few days that the problem happened more frequently, I've heard it from the back fan also.


You all are seriously my last hope.

Hardware info:
CPU: Amd Fx-8320 (don't comment, I am saving up for an upgrade)
Motherboard: Gigabyte 970A-UD3
PSU:corsair cx750 (yes it is an overkill)
Cpu Fan: Coolermaster Hyper 212 evo

Bad build in general I know, I realized it the last couple of years that I stalk this forum :-P

Any thoughts/wild guesses? The fact that the RPMs don't change during the problem and that it is completely random makes me think that perhaps the motherboard is faulty.

[Tyranitar]

That's a hard one with different possibilities...

It could be a result of air turbulences in the case.
Does it maybe happen when tge GPU fan spins up?

It could also be a result of vibrations (from the HDD) going through the case.
Did you look for other user experienced with your case?
There are some that are poorly shielded from vibrations, or even worse, enhance them.

[Granyala]

Probably vibration inside the case?
If all else fails I'd run with only 1 case fan at a time in order to pinpoint it.

[Deleted]

That's a hard one with different possibilities...

It could be a result of air turbulences in the case.
Does it maybe happen when tge GPU fan spins up?

It could also be a result of vibrations (from the HDD) going through the case.
Did you look for other user experienced with your case?
There are some that are poorly shielded from vibrations, or even worse, enhance them.

...I've changed case too, sorry for not mentioning it
The case that I now have is nzxt H440 and yes the problem continues. In any case I couldn't find anything similar to my problem and I think the case is good enough quality wise.

Probably vibration inside the case?
If all else fails I'd run with only 1 case fan at a time in order to pinpoint it.

Can't do that easily since I can't repeat the problem. For example it happened today, it could happen again or it could happen in two 2 days from now. The problem ranges from a couple times per day, to once per week.

One more piece of information: when the problem happens, if i shut down my system and then start it again, the problem stops but as you can understand it is quite annoying to have to quit everything.

Edit: sorry forgot to answer about the gpu. Since it occurs even when the system is not under load, GPU fans stay low.

[Amalaric]

I would recommend you to buy new and higher quality fans before your current fans fails.

[Fascinate]

Most likely the PSU fan.

[roent]

Probably dying fan(s)... ball bearings / sleeves eventually wear down. What you describe is exactly the problem I had years ago. iirc, gently applying friction to the offending fan's hub to slightly slow it's rotation llet me pinpoint which fan it was (and often stop the vibration -- sort of like resetting it).

You can try to clean the blades of every fan and use compressed air to get any dust out of the mechanism, but if it's dying the problem is the small moving parts.