Noisy Fan on my iMac

[Quincannon]

On Saturday I did a complete reboot to factory setting and upgraded to High Sierra Version 10.13.3 and now the fan is making a loud noise.
I googled it and tried a couple of things but without success, then I downloaded Macs Fan Control 1.4.9 (iMac12.2) but that didn't solve it either.

I bought the iMac in May 2012 so I suppose it's ageing somewhat now.

Can anyone offer a suggestion please?

Cheers

Peter

 

[Cory Cooper]

Hello,

-iMac (27-inch, Mid 2011) correct?
-How much RAM and free hard drive space?
-Have you giving it 24 hours to reindex Spotlight?
-Do the fans go to full immediately upon login?
-Have you tried SMC and NVRAM resets?
-Try checking  > System Preferences... > Accessibility > Display > Reduce transparency

C

 

[Quincannon]

Hi.

It is a 27 ins Mid 2011 model although I bought it in May 2012

16 GB RAM

380 GB free space from 1 TB

The fans go to full in about 5 mins

I tried the SMC reset but it didn't work.

I ticked Reduce Transparency but nothing changed.

Peter

 

[Cory Cooper]

OK, thanks for the additional information.

You could try running the Apple Hardware Test: How to use Apple Hardware Test on your Mac

Let us know if that finds anything.

C

 

[Quincannon]

I ran the test this morning and this is the error it reported. The Mac is running a little slower than normal too.

4sns 1 4000000 th00 9.000

 

[Cory Cooper]

OK, that is a known issue with the 2009 iMacs. There is a thermal sensor attached to the hard drive, and if that isn't registering correctly, it will cause the issue you are having.

-Have you ever had the hard drive replaced?
-Try the SMC and NVRAM resets again.
-Do you have a can of compressed air that you can try to blow out any dust in the vents?

C

 

[Quincannon]

Would a new hard drive solve the problem if the issue is with the fan?

I tried the SMC option again and it was ok for about 20mins then it came back.

I don't fancy trying the NVRAM reset and I don't have any compressed air. Is it easy to open it up and clean it?

 

[Cory Cooper]

I only asked about the hard drive, in case it was recently replaced and the temperature sensor wasn't connected properly. A new hard drive wouldn't necessarily fix the issue.

Hmmm...strange the SMC reset only corrects the issue for 20 mins or so.

The NVRAM reset probably wouldn't do anything, but it's a good troubleshooting step. It resets things like sound volume, display resolution, startup-disk selection, time zone, and recent kernel panic information, which can all be set back to your preferences in System Preferences.

No, it's not a user-serviceable Mac, and internal components can easily be damaged if you open it up. It's easy to blow out the vents on the back and bottom with compressed air however.

I have a friend who recently had a similar issue with his iMac (27-inch, Mid 2011), and it required a new logic board and graphics card to resolve it.

It would probably be best to take it in to an Apple Store if you have one close for full hardware diagnostics.

C

 

[Quincannon]

Thanks. I will do that.

Peter

 

[Quincannon]

I took it to an engineer and he solved the fan issue and installed an SSD so all it good.

Thanks for all your advice.

Peter

 

[Cory Cooper]

Excellent...glad it's resolved.

C

 

[Quincannon]

Even though I said my Mac is working fine again I haven't noticed any difference at all with the SSD.

What exactly was it supposed to do?

Peter

 

[honestone]

Hi Peter,

Glad you got things "almost" working again. But a couple of questions:

1. When you say "I haven't noticed any difference at all with the SSD", is the fan noise still occurring?

2. Regarding the SSD:

A. What exact model is it, along with its capacity?

B. Did the engineer "place" all the software on it for you? And besides High Sierra, does that also include all your "stuff" from (hopefully) a backup?

3. Did you rerun the Apple Hardware Test that Cory earlier suggested? And if you did, what does it show?

4. Besides when you initially upgraded, did you insure that all your third party (ie, non-Apple) applications are compatible with High Sierra? This site can help you with that:

https://roaringapps.com/apps

I would suspect that given it is a new SSD, a clean, fresh, "virgin" installation of High Sierra would have been completed. Then, a migration/copying of needed "stuff" from your backup.

 

[Quincannon]

Hi, thanks for your reply.

The fan is silent most of the time but occasionally it makes a slight noise for a few seconds then goes quiet again.

The SSD is a Crucial 1TB.

The engineer first installed High Sierra and then all my files from the hard drive he replaced.

I have not rerun the Apple Hardware Test. I shall do that first thing in the morning when I switch on.

All the apps installed appear to be running ok.

When I said I haven't noticed anything different with the SSD I was expecting my mac to be super fast with it but it isn't. It's just like it was before, so even though I'm pleased that it's working as well as it ever did I'm still disappointed the SDD hasn't made it faster after all the hype I read about it before hand, and also, of course, considering what I paid for it, which was £330 including labour.

Peter

 

[honestone]

My mid 2017 13" Mac Book Air, with a 252 gig SSD, does not make any fan noise, and I have OS 10.13.3 installed. But just like you, for both of my Macs (each of them SSDs: the Air as I stated, and my late 2012 Mac Mini with a 256 gig SSD), I have not noticed any real speed increase with High Sierra. In fact, Sierra was faster. This APFS business, while great in theory, has not really yielded any noticeable benefits.

One thing I did notice, though, is that when I had one of my external devices (contains a Samsung 850 Pro 512 gig SSD, with two partitions containing SuperDuper! bootable backups) connected to my Mac Mini, performance was not that "great". When I disconnected the drive, things improved.

I am especially disappointed because I make a concerted effort to keep my Macs "lean, mean, and clean". And in fact, for each of them, I am only using about 30% of the total space. And I also keep as much "junk" off each of my Macs.

OS 10.13.4 will be released soon (it's now in the 5th phase of beta testing), and supposedly it contains performance improvements. But I would not "hold my breath" with that!

 

[Allen Davis]

This is the first instance I've ever heard of where the user didn't see a significant speed improvement after installing a SSD. Is Crucial a brand that is widely trusted and has a sterling reputation? I've heard of them and know they sell RAM, but have never used any of their products. I'm curious because I've got a 1TB Crucial SSD on my watch list on eBay and was considering buying it.

 

[honestone]

I know that after I replaced the (slow) Hitachi 1 TB 5400 rpm drive in my late 2012 Mac Mini with a Samsung 840 Pro 256 gig SSD, the performance increase was definitely dramatic. However, I have seen a "little" decrease in performance on the Mini after I went from Sierra to High Sierra. And besides keeping my Macs "lean, mean, and clean", I did a fresh, clean, new, "virgin" installation of High Sierra (as opposed to upgrading "in place"). And that was after I had Erased and Formatted the SSD. It seems that this APFS "business" is (so far) not what it's supposedly cracked up to be.

As I have mentioned before, the main "slow" issues I have seen are:

1. It takes longer to boot up either of my Macs with High Sierra.

2. If I want to switch Start Up Devices (either one of my SuperDuper! backups, or Tech Tool Pro's eDrive), that process is slow. Same when I switch back.

Other than that, apps seem to run about the same. Another user had previously stated that the Office 2016 apps ran faster with High Sierra, but I am not seeing that.

Samsung SSDs are about the best ones one can get. But a Crucial SSD should be fine.