Intermittent Noise From Fan Area iMac 2020

[Inpresmoj]

Im on my 3rd replacement 2020 Imac 27"

1st one just had a loud fan so Apple replaced it.

2nd one fan was much quieter and for first few weeks it was fine, but then it started making a noise like a old type HDD been accessed, it will stop for a second and then continue making the noise. Apple suggested a few things which didn’t work so they sent me another machine.

3rd one fan isn't quite as quiet as 2nd one but it is much better than the 1st one. But same thing happened again after a couple of weeks i noticed the same type of noise as the 2nd one.

Both the 2nd and 3rd machines i was doing nothing taxing at the time it was just streaming youtube or reading a word file. I can hear the noise above music and the noise continues for hours Its very annoying as its not consistent.
Then i switch the PC on the next day and the noise has gone. I’ve only heard it once in 2 weeks on this 3rd machine and I heard it 3 times on 2nd machine in several weeks. It does last for hours once it starts though.

Im just wondering is it indexing something maybe and this is just normal and something i just have to put up with, or if its worth asking for a 4th machine?

I need a machine now really, my old machine is on its last legs and waiting for an AS imac, that also could have possible issues or things Im not keen on, I want a all in one and this 2020 iMac does everything I want now and apart from these noise issues im happy with it, its my first ever Apple product.

Im having issues with Dark Mode too so this is post is for Light Mode, spent ages trying to fix this but not having much luck
reposted same post below which can be seen in Dark mode, think i will stick to light mode moving forward as this is far too much trouble

 

[SO8]

The blank space makes me think it was ... the fan 😁

 

[Inpresmoj]

Im on my 3rd replacement 2020 Imac 27"

1st one just had a loud fan so Apple replaced it.

2nd one fan was much quieter and for first few weeks it was fine, but then it started making a noise like a old type HDD been accessed, it will stop for a second and then continue making the noise. Apple suggested a few things which didn’t work so they sent me another machine.

3rd one fan isn't quite as quiet as 2nd one but it is much better than the 1st one. But same thing happened again after a couple of weeks i noticed the same type of noise as the 2nd one.

Both the 2nd and 3rd machines i was doing nothing taxing at the time it was just streaming youtube or reading a word file. I can hear the noise above music and the noise continues for hours Its very annoying as its not consistent.
Then i switch the PC on the next day and the noise has gone. I’ve only heard it once in 2 weeks on this 3rd machine and I heard it 3 times on 2nd machine in several weeks. It does last for hours once it starts though.

Im just wondering is it indexing something maybe and this is just normal and something i just have to put up with, or if its worth asking for a 4th machine?

I need a machine now really, my old machine is on its last legs and waiting for an AS imac, that also could have possible issues or things Im not keen on, I want a all in one and this 2020 iMac does everything I want now and apart from these noise issues im happy with it, its my first ever Apple product.

This is the Dark Mode post, im having fun with this, spent ages trying to fix it but having no luck, this is why ive had to repeat post this

 

[Inpresmoj]

Just giving this post a bump with me having 2 imacs now with the same issue there must be others that have had similar issues, im just wanting to know how they got it resolved, im even thinking about keeping this imac and hoping that its fixed with an update, im just unsure how to proceed?

 

[wilberforce]

Just giving this post a bump with me having 2 imacs now with the same issue there must be others that have had similar issues, im just wanting to know how they got it resolved, im even thinking about keeping this imac and hoping that its fixed with an update, im just unsure how to proceed?

I have had two 5k iMacs, have read many threads about fan noise, and cannot recollect anyone having complained about a source of noise other than the fan, for iMacs that do not have a spinning hard drive.
Most of the threads about iMac noise are discussing whether the fan noise is now more than previously, and whether it is objectionable or not (which is of course subjective).
Either you (and your environment) are especially sensitive to noise, or you are extremely unlucky (three consecutive new iMacs with similar noise issues), or both. It is especially puzzling that you can hear the offending noise over music, and on three consecutive iMacs. As far as I know, the complaints about iMac noise are only in a quiet room.
This may be why you have had basically no responses to your post.

I recall @LadyNinja had ongoing noise issues with several iMacs. Maybe search for "fan" posts by that member.

Sorry I can't be more help.

 

[costica1234]

You can also try lowering the fan speed to 1000rpm to see if that makes any difference (note that the default speed is 1200rpm). I wrote some very detailed instructions for 2020 iMacs here: https://forums.macrumors.com/threads/1200-rpm-is-too-loud.2176357/post-29530676. Good luck!

 

[Inpresmoj]

I have had two 5k iMacs, have read many threads about fan noise, and cannot recollect anyone having complained about a source of noise other than the fan, for iMacs that do not have a spinning hard drive.
Most of the threads about iMac noise are discussing whether the fan noise is now more than previously, and whether it is objectionable or not (which is of course subjective).
Either you (and your environment) are especially sensitive to noise, or you are extremely unlucky (three consecutive new iMacs with similar noise issues), or both. It is especially puzzling that you can hear the offending noise over music, and on three consecutive iMacs. As far as I know, the complaints about iMac noise are only in a quiet room.
This may be why you have had basically no responses to your post.

I recall @LadyNinja had ongoing noise issues with several iMacs. Maybe search for "fan" posts by that member.

Sorry I can't be more help.

Thanks for your reply, yes ive been reading through posts and i cant find anyone having my particular issue. Its actually the last 2 imacs ive had this intermittent noise with, its very strange as it can be fine for a week and then just start, and all im doing is reading a web page and streaming youtube, nothing else is open. I can then hear this intermittent noise above the music, its very annoying.

The first imac i had just had a very loud fan noise all the time, it wasn't this issue. As my issue doesn't seem to be that common i think i might see if apple can send me a 4th one, perhaps my last 2 were from the same batch and i have more luck next time around