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Recently my home desktop computer has been reacting a lot more to heat levels. The fan starts maxing out just about any time the CPU is used, and it's very loud. It didn't use to do this - only in the last year or so (it's about 3 or 4 years old). I've removed all the dust I can find, but Speedfan shows it's running at about 130 degrees, and when it goes a tick above that the fan goes crazy.

Any ideas? Can the heat sink fail over time? Do I need to get better/quieter fans?

I'm not looking to put a lot of money into this system, so I'm hoping for any low cost ideas.

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Heat sinks can warp over time, and the heat paste underneath them can dry, crack, and crumble. –  kmarsh Aug 17 '09 at 13:30

9 Answers 9

up vote 3 down vote accepted

It sounds like the bearings on your fan have worn. The cheapest solution is to buy a new fan.

Remove the old one and take it down to your nearest computer parts shop and get one the same size and rating and with the same plugs to replace it.

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I recently purchased a non-stock fan/heatsink for my CPU and I have to tell you, it's made a lot of difference. The construction of the heatsink is very unique, and the fan is ridiciulously quiet. I can't even tell my computer is on a lot of the time.

And the cost wasn't too bad, I think I spent maybe $40 on it or something. Definitely a good investment.

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You might want to try the following in order of increasing cost

  1. Get some heak sink paste and removing the fan, cleaning any old paste off and applying a thin layer of new paste, put everything back together ($1-2)
  2. Replace the fan on the heatsink, the fan bearings will get old and noisy over time ($10)
  3. If you're ok to spend $30-40 then I'd just replace the heatsink/fan with a large 1200RPM one.
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Replacing the stock fan is useful.
But, I have often found that replacing the stock-fan thermal-pad
with new thermal grease (like Artic Silver 5) helps a lot.

You should also use tools like RealTemp to follow temperatures around your CPU.
A hot CPU does not just push the fan, it also reduces processing speed.

Real Temp is a temperature monitoring program designed for all Intel single Core, Dual Core, Quad Core and Core i7 processors. Each core on these processors has a digital thermal sensor (DTS) that reports temperature data relative to TJMax which is the safe maximum operating core temperature for the CPU. As your CPU heats up, your Distance to TJMax will decrease. If it reaches zero, your processor will start to thermal throttle or slow down so maximizing your distance away from TJMax will help your computer run at full speed and more reliably too.

Such tools will usually allow you to sample temperatures over time
which helps you figure out when the next hardware cleanup cycle is due.


While we are at this, it would be useful to track other temperatures like
the Harddisk, Graphics processor and the Chassis ambient temperatures.
All except the last are tracked by software; the last one uses a few strategically placed thermistors.

Tracking ratios of these temperatures over time gives you good clues on where heat is building up (or, whats about to blow up).

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It could be that the ball bearings on the fan are starting to stick a little, causing the noise. This also causes the fan starts to vibrate a little and not run as fast, which could be related to the heat.

Replacing fans on heatsinks are usually pretty cheap. I'd looking into picking one up and trying that.

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Welcome to summer. Actually my laptop has recently suffered the same fate and I just ordered replacement fans.

Some possible causes and fixes could be:

  • Dust. Looks like you've handled this already but the idea is open it up as much as you can and remove the dust. Cans of air work well here.

  • Old fans. Fans are motors and will fail over time, especially if there was a lot of dust and they were working overtime (straining the motors). Replacing the case fans is usually a simple process. CPU/GPU fans can be a pain if they're part of a heatsink module. Put your hand in front of the fans and see if they're actually blowing some good air. If not, I would try replacing the fans before doing anything else, especially if they're making noise (a sign the bearings are slipping).

  • Inadequate airflow. This could be a number of things, but the system being in a corner or enclosed space, not enough holes or fans in the case, and the like are common. It'll also cause fans to work overtime, reducing their life.

  • Heat sink has come loose. Over time, especially if it's running hotter than it should, heat sinks can come loose and screws can back off. Generally if a heat sink is hot to the touch, it's doing its job. If not and the temperature is being reported high, this is something to check out. If they need reattaching or replacing, be sure to use a good thermal compound and clean the contact points before applying.

  • You're pulling too much power. Make sure the power supply is powerful enough to drive everything you've got. Otherwise the motors won't have enough to get going. This can be a problem if you've recently added something that requires power.

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You mention that you have removed all the dust you can find... There may be dust you haven't found. If dust gets into the bearings or motor it can interfere with the rotation of the fan. This can result in excess noise and will probably lead to the motor giving out.

You probably want to consider replacing the fan entirely.

Is it only the CPU fan that is making noise? I have found that PSU and case fans can also be quite noisy when they are failing.

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You might consider installing more case fans - it could be that the CPU fan is fine, but there's little actual air going into and out of the case, so the CPU fan has to cool to a higher in-case temperature, rather than a cooler room temperature.

Make sure the PSU fan is running well, and look into getting a few 12V case fans that you can run at 5V. Make sure that you have as many fans blowing into the case as out of it, generally intake from the bottom front of the case and blowing the hot air out the top back of the case.

-Adam

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I work for a consulting firm, and one of the silly things we did was offer extended warranties for older computers. I.e. Like insurance for your desktops.

I had to look at a desktop in a bank, that was making a funny noise.

Got there, yep making a funny noise. Quite annoying. Moved the case, it stopped. Moments later it started again.

Opened the case, lo and behold the rubber band holding the power cables from the power supply (you know, the spares for extra drives, etc) had snapped due to old age, and one of the Molex power connectors was banging in and out of fan, making the noise.

Pretty funny, beautiful bank building! They had a 100 foot high ceiling with gorgeous murals and frescos. Total waste of space, but amazing to look at! I took lousy pics with my BB that really do not capture the beauty of it.

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