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mac pro early 2008 - fan noise on start up & constant "whirring" sound

C

Col127

macrumors 6502
Original poster
Sep 13, 2003
286
4
hey guys,

wondering if anyone has any ideas about my mac pro early 2008 (2.8 ghz 8-core). i've got the standard 320 gb of hd space, 2 gb of ram, and the nvidia geforce 8800 gt :) every time i start up the machine (from power off), i hear the fans go on full blast for about 2-3 seconds and then they go quiet. does anyone else have this happen to them?

also, during normal operation, i hear a constant "whirring" type sound - it fades in and out... is this normal? any ideas what's causing it? it's pretty loud... all i have open right now is safari and this is the sound it makes....

thanks!
 
The 2-3 seconds full blast is normal, because the fans go full blast until the fan control software is loaded (which takes a few seconds). Once everything is booted though it should be very quiet (not silent, but quiet).
 
For me it doesn't seem like the system fans are revving up, but the graphics card fan is definitely going ape-**it for those first few seconds.

(BTW, machine arrived today, and I am loving it. :) )
 
Col127 said:
hey guys,

wondering if anyone has any ideas about my mac pro early 2008 (2.8 ghz 8-core). i've got the standard 320 gb of hd space, 2 gb of ram, and the nvidia geforce 8800 gt :) every time i start up the machine (from power off), i hear the fans go on full blast for about 2-3 seconds and then they go quiet. does anyone else have this happen to them?
Click to expand...

That's normal, I understand.

Col127 said:
also, during normal operation, i hear a constant "whirring" type sound - it fades in and out... is this normal? any ideas what's causing it? it's pretty loud... all i have open right now is safari and this is the sound it makes....
Click to expand...

I hear something that may be similar. Then again, maybe not.

From reading around, I'd say the most likely candidate is the disk drive.
Alternatives: fan or PSU noise.

It's very hard to say just given your description: maybe you could
make a sound recording for us?
 
Col127 said:
also, during normal operation, i hear a constant "whirring" type sound - it fades in and out... is this normal? any ideas what's causing it? it's pretty loud... all i have open right now is safari and this is the sound it makes....
Click to expand...

Yep, mine does the same constant whirring type sound that fades in and out. The same thing with the fans going full blast during start up. Probably normal, I suppose; I've read the same from other threads. Fact is, I check this forum all the time just to see if any one has the same case as mine. I don't worry about it, though it can be irritating sometimes.
 
Mac Pro 8 core_4MOT/2/40000004:EXHAUST

My very new Mac Pro 8 core with 2GB RAM is making, sometimes, a loud and constant fan noise, something like a full power rotation that stay sounding for a long time... At most, it starts when the computer come back from the sleeping mode. But sometimes the noise stops and it works quiet. This is coming and going... I've tried to run the AHT (Apple Hardware Test), to obtain some diagnostic about any problem and I've found an error:

4MOT/2/40000004: EXHAUST

Does anybody know what is this and how I can fix that problem???

Thanks,

Rodrigo
 
Sandock said:
Yep, mine does the same constant whirring type sound that fades in and out. The same thing with the fans going full blast during start up. Probably normal, I suppose; I've read the same from other threads. Fact is, I check this forum all the time just to see if any one has the same case as mine. I don't worry about it, though it can be irritating sometimes.
Click to expand...

Same whirring noise here. may try reseating the hard drives
 
4MOT/2/40000004: EXHAUST

Does anybody know what is this and how I can fix that problem???

Fan Speed:

hard drive: 500rpm
exhaust: 2798rpm
power suply: 648rpm
CPU fan: 2761rpm

SMC version: 1.15f3
 
The second 2008 mac pro that I had (and returned for graphics freezing) had something resonating at the top of the machine, perhaps the case itself. I found that simply putting a heavy book on top of the machine halved the volume of the whirring sound. Often computers resonate somewhere, and by pressing in different places on the case you can track it down and then do something to apply pressure to that area. My G4 MDD powermac had a side panel that resonated with the hard disks, until I stuffed something between the side of the case and the wall to keep some pressure on it.
Often the resonating sounds are the ones that come and go apparently randomly, but this is probably due to slight distortions of the case from temperature changes, or the computer being moved or twisted slightly etc. Just reseating hard drives can often help.
The fan pulsing sound may be due to a fan not being perfectly balanced or straight, making its axle kind of "process" in circles much slower than the actual rotation speed (a bit like how the tip of a gyroscope walks along a table in small slow circles). Or it may be an acoustic phasing issue caused by two fans where one is running very slightly faster than the other. I seem to remember hearing of someone solving their two fan phasing noise by slowing one fan down slightly by sticking some blue tac (a brand of the stretchy stuff you stick posters onto walls with) on its blades to make it heavier than the other one. Once the speeds are sufficiently different you don't hear the phasing.
 
hmmmmmm.. i wonder if this is normal for everyone - i find the noise quite bothersome. my old powermac g5 was MUCH quieter than this mac pro; maybe i'll give apple care a call. my mac exhibits the reboot from sleep problem too. this is quite disappointing considering how long i had to wait for my mac to arrive since i ordered it......
 
Infrared said:
What thermal sensor readings are you getting?
Click to expand...

Thank's for your reply... but what do you mean with thermal sensor readings? Temperature? This is what I could see with IStat Pro:

CPU A 38º
CPU A 28º
CPU B 40º
CPU B 28º
Ambient 25º
Northbridge 38º
Expansion Slots 29º
HD Bay 1 26º
 
HD Bay 2 31º
HD BAy 3 31º
HD Bay 4 32º
Mem Bank A1 30º
Mem Bank A2 31º
Mem Bank A3 32º
Mem Bank B1 30º
Mem Bank B2 30º
Mem Bank B 32º
Mem Module A1 45º
Mem Module A2 37º
Mem Module B1 126º
Mem Module B2 126º
Power Suply 1 52º
Power Suply 2 55º
HD local 40º
HD1 45º
HD2 46º
HD3 46º
 
eureka!

Don't need to answer again my friend. I've pulled out this two burning memories and found the x of the question...
thanks for all
 
Rodrigo Lima said:
My very new Mac Pro 8 core with 2GB RAM is making, sometimes, a loud and constant fan noise, something like a full power rotation that stay sounding for a long time... At most, it starts when the computer come back from the sleeping mode. But sometimes the noise stops and it works quiet. This is coming and going... I've tried to run the AHT (Apple Hardware Test), to obtain some diagnostic about any problem and I've found an error:

4MOT/2/40000004: EXHAUST

Does anybody know what is this and how I can fix that problem???

Thanks,

Rodrigo
Click to expand...

I'm a Mac newbie as I just switched from PC and got the MP on Monday. Last night I put in to 750GB Spinpoint F1 drives and after restart the two front fans turned on full blast and would not go off. I ended up shutting it down and after rebooting they were off and remained off overnight. The MP awoke from sleep this morning perfectly and the fans remained off.

What I would like to know is

a) how did you find the error code? Again, I'm a newbie so i don't know how to do much of anything.
b) it looks like later in this thread you solved the problem. Could you tell me what you did?

Thanks
 
bpjauburn said:
I'm a Mac newbie as I just switched from PC and got the MP on Monday. Last night I put in to 750GB Spinpoint F1 drives and after restart the two front fans turned on full blast and would not go off. I ended up shutting it down and after rebooting they were off and remained off overnight. The MP awoke from sleep this morning perfectly and the fans remained off.

What I would like to know is

a) how did you find the error code? Again, I'm a newbie so i don't know how to do much of anything.
b) it looks like later in this thread you solved the problem. Could you tell me what you did?

Thanks
Click to expand...

Open "Console.app" in Utilities folder (in Applications folder). Look in "Console Messages" and "system.log". You can see everything your Mac has done or is doing. This is an indispensable diagnostic tool when things are not working properly. There are also many other logs available to peruse. Most logs will be undecipherable to most of us but many can point you in the right direction to track down the cause of a problem.
 
bpjauburn said:
I'm a Mac newbie as I just switched from PC and got the MP on Monday. Last night I put in to 750GB Spinpoint F1 drives and after restart the two front fans turned on full blast and would not go off. I ended up shutting it down and after rebooting they were off and remained off overnight. The MP awoke from sleep this morning perfectly and the fans remained off.

What I would like to know is

a) how did you find the error code? Again, I'm a newbie so i don't know how to do much of anything.
b) it looks like later in this thread you solved the problem. Could you tell me what you did?

Thanks
Click to expand...


At first, you can try to run the AHT (apple hardware test) that comes with your OSX installation CD. Press "d" while restarting to boot from CD. If it's a hardware problem, you will find an error code there... I've downloaded a widget called iStat Pro too. It's a nice tool to get computer's temperatures, fan rotation, disk usage...and it's free. I've supposed that my fans were at full blast because of memories B1 and B2 very high temperatures. After that, I've pulled out the burning memories. Everything becomes normal and quite. I was right. Then, I've put the memories back, just in case, to know if I was really right... attaching it carefully. For my surprise the problem has disappear. Until now. Happy again... Good lucky.
 
Hey, just a quick tip, moving my HDD from bay 1 to bay 3 made everything more quiet. Just to do with the acoustics I think, not fan speed etc. Try it and see,
 
Rodrigo Lima said:
At first, you can try to run the AHT (apple hardware test) that comes with your OSX installation CD. Press "d" while restarting to boot from CD.
Click to expand...

With the new MPs you don't need the CD. Just boot from the HD
and hold down D.
 
Rodrigo Lima said:
4MOT/2/40000004: EXHAUST

Does anybody know what is this and how I can fix that problem???

Fan Speed:

hard drive: 500rpm
exhaust: 2798rpm
power suply: 648rpm
CPU fan: 2761rpm

SMC version: 1.15f3
Click to expand...

your exhaust and cpu fan speeds are way too high.
all 4 of those should be in a very similar range.
 
Rodrigo Lima said:
4MOT/2/40000004: EXHAUST

Does anybody know what is this and how I can fix that problem???

Fan Speed:

hard drive: 500rpm
exhaust: 2798rpm
power suply: 648rpm
CPU fan: 2761rpm

SMC version: 1.15f3
Click to expand...

My fans are as follows-

Exhaust 599rpm
CPU 500rpm
PSU 599rpm
HD/Explation 798rpm

CPU is running at about 200% right now, admittedly I only have the 4-Core single chip machine so maybe the CPU fan doesn't have to move so much air, but still, 2700rpm is pretty high, i've not managed to get mine passed 1000rpm when the CPU is at 400% :eek:

Thinking about it though, I am in a pretty cool room, iStat is reading ambient at 19ºC and the CPU is at 31ºC, I'd guess the room temp is cooler still


As to fixing the problem, i have no idea, sorry :eek:
 
The graphics card having the full fan whirr for 2-3 seconds is perfectly normal.

It has done that on my last 3-4 graphics cards on the PC for both Nvidia and ATI and also now on my new Mac Pro (2008).
 
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