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Buzzing/Rattling Fans?

peskaa

peskaa

macrumors 68020
Original poster
Mar 13, 2008
2,104
5
London, UK
My 2009 Mac Pro has recently started making a horrible buzzing/rattling noise, and I think it may be coming from one of the fans. It's incredibly annoying - warranty job, or is there something easy that I need to do to fix this?


Attached iPhone recording of the buzz. It's intermittent, and moving the MP usually fixes it.
 

Attachments

  • 20101003 204420.m4a.zip
    73.3 KB · Views: 228
Which fan is it coming from? Are you still under AppleCare? They'll certainly replace a fan for you.
 
It's coming from somewhere round the optical bay (ie: top front), but not totally sure. As for AppleCare, yes, covered until 2013.
 
my 2008 had some problems with buzzing and it turned out that the glue holding the magnets together that lock the CPU covers in place had come apart (hot temps?). A few balls of bluetack fixed my problem.

I'd take the cover off and have listen around...
 
@EKWIPT

Could you elaborate a little more about your problem? Maybe with a picture?

I have had my Mac Pro, 2010 6-core, in the Apple store twice and they fail to refuse the noise is there. However, in my dead silent office I can hear it. To me is sounds like a bearing problem. I told the Genius that the problem is in the fan built-in to the CPU heatsink. He told me that there are only 3 fans in the entire Mac Pro. I said no, he said yes only three. I then proceeded to remove the processor tray and point to the CPU fans. I'll admit, I did not know that they were there also.

Anyways, they said it was fine.

The only way I could diagnose the problem, was by opening the side panel with the Mac Pro powered on the find the problem. I was also surprised to find two tiny fans built-in to the large heat sink.
 
hrevya.jpg
 
just listened to the file in the first post. It doesn't sound like a fan bearing. It sounds more like the PSU.
 
mjsmke said:
just listened to the file in the first post. It doesn't sound like a fan bearing. It sounds more like the PSU.
Click to expand...

I'm still trying to check where it's coming from - but at the moment every time I pull the MP out from under the desk, pop the latch and take the door off the horrible noise stops! Unfortunately my closest repair store is an hour and a half away, and my luck would be that it simply wouldn't evidence at an appointment.
 
peskaa said:
I'm still trying to check where it's coming from - but at the moment every time I pull the MP out from under the desk, pop the latch and take the door off the horrible noise stops! Unfortunately my closest repair store is an hour and a half away, and my luck would be that it simply wouldn't evidence at an appointment.
Click to expand...

This makes it seem less like the PSU and more like a loose fan or rattling hard drive. I agree that the file you attached sounds exactly like a buzzing PSU but not with this behavior. Next time, try pulling out your MP, leave the door on, and listen right next to where the power plug connects. If it's not any louder or doesn't sound like it's coming from there, you've got a different issue.
 
It's probably vibrations coming from one of the HD sleds. Mine does the same thing...this is poor engineering imo.
 
mjsmke said:
just listened to the file in the first post. It doesn't sound like a fan bearing. It sounds more like the PSU.
Click to expand...

I know how a buzzing PSU sounds, and that's not it.
I'd definitely go for vibrations caused by either mechanical hard drives or fans.

OP, please check you ODD bay and eventually the power supply cable cover behind it. This is where most rattlings come from.
 
peskaa said:
I'm still trying to check where it's coming from - but at the moment every time I pull the MP out from under the desk, pop the latch and take the door off the horrible noise stops! Unfortunately my closest repair store is an hour and a half away, and my luck would be that it simply wouldn't evidence at an appointment.
Click to expand...

I just listened to the file you uploaded. This along with what you said above makes me think we have the same problem, i'm about 80% sure.

What you need to do is check all the plastic seals and covers. I'm pretty sure you'll need to remove the seals and re-glue the magnets. Did you see my picture, it's not elegant but it "Just Works" :apple:
 
ekwipt said:
I just listened to the file you uploaded. This along with what you said above makes me think we have the same problem, i'm about 80% sure.

What you need to do is check all the plastic seals and covers. I'm pretty sure you'll need to remove the seals and re-glue the magnets. Did you see my picture, it's not elegant but it "Just Works" :apple:
Click to expand...

The 2009 machines don't have any plastic covers that might rattle.
 
You're right just checked out some photos, there's a lot of places for the rattling though. Whate are the covers made of where the optical and power supply are. Or maybe the exhaust on the middle fan. Or the CpU covers.
apple_mac_pro_nehalem_cebit09.jpg
 
If it's really a rattle instead of a buzz, the most common issue I've seen are hard drive sleds. Try running with the case open and putting your hand up to each one, one at a time. Still gotta find out which area its coming from though :p
 
ekwipt said:
You're right just checked out some photos, there's a lot of places for the rattling though. Whate are the covers made of where the optical and power supply are. Or maybe the exhaust on the middle fan. Or the CpU covers.
Click to expand...

Actually there are no lose covers in the 2009/2010 systems.
The ODD bay itself is a single unit, just as it was in the earlier models. This is actually the only lose part in the Pro, which might cause the noise.

The PS is (alike the previous systems) covered by a fixed plate of aluminium. No possibility to rattle.

There are no CPU covers. What you see in the picture you provided are the actual heat sinks and there is absolutely no way that they might have become lose.


As mentioned before, I opt for the optical bay, especially in case that the OP has mechanical hard drives mounted there.
 
I have a 2009 2.93GHz Quad Core Mac Pro that is making a very faint but audible "rattling noise". It's very annoying, and I have had to move my machine to the floor just so I don't hear it. It comes and goes about every 45 seconds to one minute, and lasts about 5 seconds each time. I have recorded the sound as an MP3, so you can hear it. You can clearly hear it's a "rattle." I believe it's coming from the lower intake fan on the front of the unit.

Listen to this. Turn your speakers up to hear it:

http://www.wardcurry.com/rattle.mp3

Let me know if this sounds anything like yours. It's definitely a "rattle" and not a "buzz". It sounds like a loose ball bearing in one of the fans.
 
WardC said:
I have a 2009 2.93GHz Quad Core Mac Pro that is making a very faint but audible "rattling noise". It's very annoying, and I have had to move my machine to the floor just so I don't hear it. It comes and goes about every 45 seconds to one minute, and lasts about 5 seconds each time. I have recorded the sound as an MP3, so you can hear it. You can clearly hear it's a "rattle." I believe it's coming from the lower intake fan on the front of the unit.

Listen to this. Turn your speakers up to hear it:

http://www.wardcurry.com/rattle.mp3

Let me know if this sounds anything like yours. It's definitely a "rattle" and not a "buzz". It sounds like a loose ball bearing in one of the fans.
Click to expand...
I hear a grinding (bearing or bushing) and thwap-thwap-thwap... type of sound (fan blade hitting the frame I think).

Where is it coming from?

I ask, as it seems they changed the fan in the PCIe slot area according to the P/N's between the 09 and 10 systems. So I'm thinking it's a combination of a supplier and specification (airflow) change as a means of getting a cheaper replacement. Going from ball bearing (or fluid,... bearings) to bronze bushing based motors would definitely lower the cost, and would be more prone to noises like what you're hearing.
 
I want you to get a listen to this...I stuck my iPhone in my Mac Pro and recorded the sound again, this time I captured the sound alot better and you can hear the intermittence between "rattles". It's about a one minute long sound file, and you hear FOUR times in one minute, so about every 15 seconds it rattles for 5 seconds. Here is the audio file. You can here it LOUD this time:

http://www.wardcurry.com/rattle2.mp3
 
WardC said:
I want you to get a listen to this...I stuck my iPhone in my Mac Pro and recorded the sound again, this time I captured the sound alot better and you can hear the intermittence between "rattles". It's about a one minute long sound file, and you hear FOUR times in one minute, so about every 15 seconds it rattles for 5 seconds. Here is the audio file. You can here it LOUD this time:

http://www.wardcurry.com/rattle2.mp3
Click to expand...
It still sounds like a fan to me, but what I don't know, is which one it is.
 
I have determined the culprit was the heatsink fan, the "BOOSTA" fan on my single-processor Mac Pro. I have fixed the situation for now, it's not making the noise anymore.

What I did: Used SMCFanControl, set "BOOSTA" to 4000rpm and ran that fan on high for one minute. Set it back to lowest setting...I think the fan had never been run on high before, and somehow this has fixed the problem...I am going to post this over in the other thread too so hopefully this can help somebody.
 
My noise has been fixed. My machine is whisper quiet! I am so happy!:)

They fan located in the CPU heat sink was the problem. I can understand Apple wanting to follow protocol and go through these 48 hour stress tests and all, but sometimes you got to trust the customer. I am glad they did. They placed an order for spare parts to replace all the system fans without me bringing the machine in. That was very generous of them. I told them specifically which fan I though was the problem and requested only that fan be changed. They said "OK" and they did it and the problem is gone.

I also tried what another forum member said in using SMCfancontrol to check the BOOSTA fan. I could follow the noise to BOOSTA fan located in the CPU heatsink, the only problem mine did not go away after leaving it at 4000 rpm for several minutes.

I love :apple:

What else can you ask for?
 
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