Precision 3431 fan is loud when system is idle.

The fan being noisy at idle might be due to chassis or heatsink design.  This thread might help.  And this recent thread.

There doesn't appear to be just one quick solution.  Many like HWiNFO64.sys.  Other solutions are in the threads.  Taking the fan below 800 RPM isn't recommended by Dell, but it may work for you if it doesn't raise CPU temps at idle or light load.

Hi Allan,

Thanks for taking the time to reply.

Here are answers to your questions:

There are no clunking or rattling noises.

I have tried the latest BIOS (1.1.6) then backed it out, I am currently running 1.0.3. Changing BIOS versions made no difference.

The noisy fan appears to be at the front of the case, not sure which one this is. HWINFO64 only lists one FAN in its sensor report.

The fan noise does not change much it at all under some load, but I have not driven it very hard.

The noise is constant.

During the diagnostic tests the fan went up to around 2900 RPM and sounded like a jet taking off. During normal operation it is much quieter than that, but still not quiet.

Thanks

John

Hi Alan,

I received your private message, but my reply was not delivered, your message was sent from

noreply@dellcommunity.dell.com

Please resend with you email address and I will resend my reply,

Thanks,

john.

@FlongX is the fan simply loud or is it making an abnormal noise i.e clunking, rattling etc?

What version of the BIOS are you running?

Have you tried updating the BIOS to the latest version , if not already done, to see if there is any difference?

There are 3 fans in the system, PSU, CPU and chassis fan. Have you been able to identify exactly which fan is causing the noise?

Does the fan noise change pitch or tone when the system is under load?

Is the noise constant or does it come and go?

When you ran the fan test in the diags, could you hear the noisy fan during the test?

I'll drop you a private message to get your service tag details.

Alan

@FlongX I have received multiple responses from customers today via private message. Can you try responding again please.

Thanks, Alan

@FlongX Here's the link to the service manual - https://www.dell.com/support/manuals/us/en/04/precision-3431-workstation/prec3431sff_service_manual/removing-the-system-fan?guid=guid-3a9886ea-e5b7-4d15-81c4-d23003d42573&lang=en-us

Can you disconnect the cable that's marked number 1 on the diagram and then restart the system.

After disconnecting the chassis fan, is the system still loud? (This will tell us if its the chassis fan or the cpu fan that is causing the problem)

Turn off the system and then reconnect the fan cable to the motherboard. Does the noise issue improve?

Alan

Hi Allan,

Sorry to take so long to get back to get back to you, life gets in the way sometimes.

So, here is the state of play.

The "system" fan is definitely the noisier of the lot

The CPU fan is audible, but less so than the system fan..

I took out the Radeon graphics card and used the Intel built-in graphics hardware instead, the noise reduction was slight. Interestingly, the fan on the Radeon card is doing over 2000 RPM and is much quieter than the system fan which is spinning at about 790 RPM.

I updated the BIOS to the latest release (1.2.1), no difference.

So, I am no further forward.

The "noise meter" app on my phone shows the ambient noise level when the system is in sleep mode to be about 25 dB.When the the system is running at idle, it goes to about 45 dB.

Although this is not a jumbo jet taking off kind of thing, its a constant low-level hum, and quite annoying.

I suspect that the fan is in fact running "as expected", it may well be that the system designers simply made a poor component choice when they selected the fan to use.

I think I'll do some research to see if there are any "after-market" alternatives for the system fan.

Cheers,

John.

Remember it might not be just the fan.  Just the fan by itself, not mounted to anything, may be quiet.

Fans swirl air.  Resistance can be encountered as it blows air into straight heatsink fins, for example.  It's that resistance that can make noise.

A box fan with a grill with straight slots make more noise than box fans with circular grills.  The grill with straight slots also cuts down on air flow some as it resists the circular motion of air from the fan blades.

One of my led fans (120 mm) spins at 2,500 rpm quiet as can be.  It's also not blowing against anything to cause noise making resistance.

hello

i have the same issue (cont annoying zooming noise even when nothing is done on the pc).

i did the steps you mentioned and now i don't have any zooming noise anymore.

the noise clearly comes from the fan just behind the dell logo (front of the pc)

Hi @FlongX,

To use private message, tap on Alan's name, then scroll all the way down to Contact Me.  Also, save private messaging in bookmarks for easier access.

I just discovered the problem with the loud CPU fan.  It is the way Dell is (mis)handling Intel Turbo Boost.  They are aware of the problem according to the support person I spoke to today.  As a workaround, disable Turbo Boost in the BIOS under Performance.  Since I did that a week ago there has been no fan spin up and the 3431 is very quiet!