(SOLVED) 2018 Macbook Pro A1989 making popping/crackling sounds when CPU hot? Audio file attached.

[joshAU]

Hi all.
I have3 a mid-2018 MBP A1989 (EMC3214), that makes a popping/crackling sound when the unit gets hot.

I've removed the base cover and cleaned the fans - which were already spotless, and seem to spin fine with zero resistance.

I thought that the microphone may have been picking up some sort of electromagnetic interference from the right hand fan, however I've muted the microphone, and also muted the speakers, and I can still hear the sound.
I also disconnected the speakers, with no change.
I also reset the PRAM/SMC.
I tried installing SSDFanControl, but it doesn't correctly detect the fans on this model.

The noise seems to come from the right hand side to the machine, and if I manually stop the fan, the noise ceases immediately.
So it should be the fan, however I've never heard one that sounds like this one does!
I've attached a recording of the sound, in case it helps.

I'm assuming replacing the fan should fix it, but, any other suggestions or known issues anyone can think of?
Thanks for reading.

 

[2informaticos]

If the noise stops when block the fan, I can only think about fan issue...

 

[joshAU]

@2informaticos
Yes, you are right.
I ended up replacing the fan with a known good one, and the issue seems to be resolved.
It was annoying, as it necessitated removing the logic board to replace the fan.
Interestingly, the failed fan seemed to spin far more freely than the good one.
Thanks for your input.

There seems to be quite a few posts out there about this issue, but this particular one was definitely the fan, despite the noise sounding more electrical...
But after spinning the fan with a blower, while removed from the system, and reproducing the issue, it was apparent it was the fan.