Model A1312 / Mid 2011 / 2.7 & 3.1 GHz Core i5 or 3.4 GHz Core i7 Processor

359 Questions View all

Why is the fan so loud?

The fan on my iMac Intel 27" is so loud and I wonder how to fix it

Answered! View the answer I have this problem too

Is this a good question?

Score 2

Comments:

Do you have any other symptoms other than a loud fan? What are the last three numbers of your serial number?

by

is it just loud or is it screeching?

by

Maybe the fan is heavier because of the dust on it

by

My 27" imac had the same problem. The problem was the Ambient Temperature sensor. The ambient sensor plug is on other side of CPU processor. And I think about the temperature of processor, it caused desoldering of logic board one of the capacitor of temperature sensor system. Sorry about my english, It was my problem and was solved, maybe could help others!

by

The problem here is that the OP never came back and told us her exact machine so all the answers are just speculation.

by

Add a comment
Deck the Halls
With tools and Fix Kits

12 Answers

Chosen Solution

I wouldn't just drop lubricant on the fan. If the fan is clogged with dust or nicotine it will slow it down even more.

If you can access the fan use some 91% (or 91-99%, do not use anything with a lesser percentage as they can be conductive and if accidently dropped onto a system / logic board can cause electronic components to short out) Isopropral (rubbing / the white NOT green stuff) alcohol and a brush to clean away the dust and debris then add about 2 drops of 3 and one oil down in the center where it gets inside of the fan housing.

If it still makes noise, you probably have a bearing going out - these fans spin hundreds of revolutions per second and will simply wear out ... in this case, replace it, the fans only cost a few bucks.

Was this answer helpful?

Score 6

Comments:

When your in there also use something like a tooth brush, with a dab of alcohol ^ mentioned above to clean off any dust on the exhaust vents.

by

Add a comment

If you changed the hard drive to one without Apples firmware, this can cause run away fan issues.

Was this answer helpful?

Score 5

Comments:

Then how can we solve the problem?

by

jcarter - Which system do you have a '09 or '11 model? There are different answers here depending on the system. The '11 cable is the link from OWC below in my answer.

by

11/30/17 - Just to update this old question,

I installed a 3.5" Seagate FireCuda SSHD into a 2011 27" with no temperature cable. Got the expected racing fan issue, installed the OWC 2011 Thermal sensor adapter and issue is gone!

OWC - In-line Digital Thermal Sensor for iMac 2011

by

Add a comment

westly197 - Well, Yes & No here ...

From the '11 model forward Apple uses custom firmware within the HD to allow the internal thermal sensor (note: not all drives have this sensor) to be used as part of its SMC services which in turn controls the RPM's of the fan or fans of the system. If you try using an older non-compliant drive the fans will ramp up as SMC services will think the sensor within the HD is defective. Over time the fans will wear out and the system will be very noisy compared to what it should sound like. Heres a collection of good write-ups from OWC that describes the issue: Apple Further Restricts Upgrade Options on New iMacs and Apple’s iMac 2011 Model Hard Drive ‘Restrictions’ and iMac Hard Drive Upgradeability Expanded!

OWC created a special cable so people could put in noncompliant HD's into the '11 system '11 Upgrade kit at the same time Apple was also working with the JEDEC standards group which over see's the SMART HD standard. While it took quite a bit of time Apple was able to get the group to alter the standard so the thermal sensor with in the HD could be accessed in a common method and not interfere with the performance the the drive (which was why Apple needed to go with custom firmware at the beginning). Now HD's that comply with the updated standard no longer need the OWC cable and have the newer SMART services within their firmware.

If you look at the HD's package you should see an Apple logo on it which is the only clue that I know of. The reason you don't see anything other than that is the drive vendors still have a lot of noncompliant drives out there and they have also being going though a bit of a market collapse and contraction (being more focused on survival). I also suspect Apple may also be asking for a bit of money for the drives they certify as workable.

In the end you need to be smart shopper on what you buy.

Was this answer helpful?

Score 3

Comments:

Hey Dan, I have the 2011 iMac and just faced this issue so thats why its on my mind. Also the newest models are less likely to have fan issues. I am interested in knowing what drives might work without the need for the cable. I've not heard this before and was under the impression only an Apple drive with special firmware for the mid2011 models was required. Ive not read anything indicating any off the shelf standard drive would work.

by

Add a comment

Check if there are layers of dust on the blades or in the housing of the fans. Buy a can of pressured air and blow off the grit. Be careful to hold fragile components in place so they dont break, e.g. fan blades.

Was this answer helpful?

Score 1
Add a comment

there is no temp sensor cable on 2011 27" iMac hard drive and I've replaced it with the 1 TB WD from my 2010 iMac and I'm sure that its the cpu fan not the hard drive fan that runs at full speed , I've installed windows 8 using bootcamp and when I run fan control software in windows it shows that the GPU temperature goes to 69 to 74 degrees I think that might be the problem

if you hold alt option key and keep viewing the boot screen even for a long time the fan works just normal but when it starts to boot to an OS (windows or OSX) it starts to work at full speed

Was this answer helpful?

Score 0

Comments:

You are correct there is no external sensor like the older 2008/2009 had. The 2010 models used a special cable to gain access to the manufactures testing sensor. In the 2011 Apple was able to alter the drives they bought to have the sensor directly accessed though an unused pair of wires in the SATA cable harness. So both the 2010 & 2011 use the internal sensor for SMC to gain access to the heat levels of the drive to be more effective in system cooling. If the sensor cable (2010) or non-Apple HD in the 2011 model is not used SMC goes into fail safe ramping up the fans to offset the possibility of over heating.

by

Add a comment

In the iMacs I have worked on there is a temp sensor cable that runs from the hard drive to the logicboard. You are right that the hard drive itself does not have a fan but if the iMacs use a specific kind of hard drive and there is a thin cable that runs from the hard drive to the logicboard that is called a hard drive temp sensor cable. If that cable is missing it will cause the fan to run at high speeds. I learned about this while working at an apple store. Look it up.

Was this answer helpful?

Score 0

Comments:

The 2010 and there 2011 models now use the built-in sensor either via a custom cable per the given drive or in the case of the 2011 models Apples custom HDD's.

by

Add a comment

I had the same problem when I swapped out the HD in my imac 27" mid-2011 with an SSD drive. I believe the fan began running full throttle because it did not know how to process the temperature readings of the new drive etc.

I searched online and came across this website - http://www.hddfancontrol.com

(Parenthetically- I am not that tech savvy but I do not recall seeing or detaching a temp sensor or wire)

I installed their program and have not had any problems since (it's been at least 6 months).

Good Luck!

Mike

Was this answer helpful?

Score 0

Comments:

Using the hardware method is much better! Here's what you need: OWC In-line Digital Thermal Sensor for iMac 2011 Hard Drive Upgrade. We have found the software methods are not as good and if the settings mis set can either wear out the fan's or damage the logic board.

by

That is true. The software from the website above is fantastic. About $35. The iMac went completely quiet. You can set the temperature and speed of the fan as well. I strongly recommend it. Tin

by

After installing 2TB toshiba drive i got same problem. I solved it with 'Macs Fan Control'. No need to waste 35$. Get fun

official link: http://www.crystalidea.com/macs-fan-cont...

by

All I can say here is: Caveat Emptor

Any software solution that defeats the thermal controls the system has can effect your lifespan of your system or cause other odd effects.

The best approach on these systems is to use drives who's firmware works with the internal sensor correctly (an OEM Apple drive) or use a external sensor that intercepts the signal which is the solution I prefer so I can use any drive OWC In-line Digital Thermal Sensor for iMac 2011 Hard Drive Upgrade

by

Add a comment

There is a cable coming from the motherboard to the back of the screen that splits in two to the left of the ribbon cable, I guess the ambiance thermal monitor is there, it is cover with some tape, if the top plug unplugs the fan goes full speed it is very easy to do by tilting the screen ,and not notice it, remove the tape very careful end re-plug the top plug and problem is solved.

Was this answer helpful?

Score 0

Comments:

Thats the older 2008/2009 models. The 2010 & 2011 use the internal sensor.

by

Add a comment

Thank you Dan. I was going to purchase Apple brand harddrive used in 2013 Imacs. And then, I was going to install this hard drive in my 2011 Imac as a remedy. The harddrive you suggest, does it have to be a SSHD? Can I use regular SATA3 harddrive, as well?

Was this answer helpful?

Score 0
Add a comment

I have this issue on my 27 inch 2011 iMac. First showed up after a trip overseas and it was well packed in an airport "rock band" style case. Apple store in Spain could not resolve it.

Was this answer helpful?

Score 0

Comments:

Did you replace the hard drive at some point? Fan's also do wearout. You might want to get a good thermal/fan sensor app like TG Pro it will allow you to see whats going on and let you test your fans.

by

Add a comment

I've seen this problem before and it was because the hard drive was replaced with a different brand but the hard drive sensor cable was not changed. Different brands use different temp sensor cables. That might be the problem.

Was this answer helpful?

Score -1

Comments:

This model iMac doesn't have the sensor cable, there is no real work around aside from running software to control the fans' speed.

by

Add a comment

give it a good oiling with some grease ..don't use WD40 it good but lasts only a few days ..give it a good clean as well.

Was this answer helpful?

Score -2

Comments:

Lube is the worse thing here! It will act like a magnet collecting dust jamming up the fan.

by

Add a comment

Add your answer

Jessica Holst will be eternally grateful.
View Statistics:

Past 24 Hours: 12

Past 7 Days: 111

Past 30 Days: 622

All Time: 27,224