Grumbling noise from iMac

iniall

iMac 21.5-inch late 2015 has recently been, well, grumbling. It's a weird sound that literally sounds like someone with stomach problems. It seems to be coming from the top left of the back and appears to be random, not seemingly related to processor coming under strain. Anybody heard of something like this?

Sad Professor

Probably either the hard drive is dying (check smart status in disk utility, run scan etc) or could be power supply failing. Either way back up now before it dies.

iniall

Thanks for the reply. The Smart status reads verified, so I presume the hard disk is ok. Any suggestions how can i check if the power supply is in trouble?

Alanstrainor

Backup all your information regardless. Photos, docs etc.

Sad Professor

Smart status isn’t totally reliable unfortunately, so hdd could still be failing. However you would probably be getting a lot of beach balls.

iniall

Backing up as i type. Rattle/Grumble still happening intermittently. Never had an issue like this before with any Mac.

iniall

Sad Professor wrote: »

Smart status isn’t totally reliable unfortunately, so hdd could still be failing. However you would probably be getting a lot of beach balls.

Not really seeing any real performance hit as of yet. Ran Apple diagnostics and it's saying fine as well. Strange.

Type 17

Probably a worn fan, but back up and maybe avoid any crucially important work on it until you find the cause and sort it out.