I wanted to clean my computer CPU heatsink and fan itself, because the temperature is not what I wanted. About (50C ~ 70C). I have Intel Core 2 Duo E4300 @1.8 GHz (LGA775).

The heatsink wasn't so scary filled with dust but I wanted to clean it anyway. I didn't know how to get heatsink with fan from the socket. So after 25 minutes I've figured it out. But I didn't know how to get it back on so I spent a lot time getting out the motherboard from the case.

the fan

The fan and heatsink... The case and all components are clear of dust. (I'm tired now). Then I put all back just the way it was, well did few things on cable management. But the problem was that I didn't know how to connect front audio connectors. I had Windows XP hibernated. So I started the PC and everything was normal, except CMOS memory was clear. I configured the BIOS just the way it was and while I was doing that I saw about 58C CPU temperature and fan at 1789 RPM. Restarted the computer with new settings applied. But Windows halted with Blue Screen (I forgot what error it was but something with KERNEL).

Restarted the PC and deleted hibernation session and everything was back normal. But couldn't record any sound from front panel microphone. The problem was that I messed ground wire with mic. Again after fixing it I turned computer on. No problems. The fan currently is noisy and temperature was 78C. The temperature before was 55C - 60C at idle. Now it's about 60C. If I do something then temperature raises to 79C. While speaking in skype the temperature was 82C.

Could this problem occur because of the thermal grease (it's old and never replaced)?

The problem wasn't in thermal paste (because I didn't touch it). The problem was that I installed heatsink wrong. Now instead of regular 60C CPU temperature the CPU is at 48C (cool).

  • Are you sure you have the heatsink mounted securely? If it's on tight, you should be able to tug and the motherboard should move with it before the heatsink comes off. – Shinrai Jan 12 '12 at 17:22
  • @Shinrai I don't get you. Sorry.. – Little Helper Jan 12 '12 at 17:24
  • So you are reusing the thermal paste you applied a long time ago instead of clueing the components and applying it anew? – Daniel Beck Jan 12 '12 at 17:25
  • @Roberts - You removed the heatsink. Are you sure you put it back on properly? If it's loose, the processor will run very hot. – Shinrai Jan 12 '12 at 17:35
  • @Shinrai I spinned it around - 180° – Little Helper Jan 12 '12 at 17:36

Yes, it could be the thermal paste, or even not quite a flush mount. I would suggest picking up some new thermal paste from either an online resource like Newegg, or from a local retailer like Fry's or Microcenter and follow the instructions provided with the product closely. Additionally, make certain the heat sink is flush, and mounted firmly with all 4 pegs. If even one is loose, the gap created could cause the problem you are having.

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    beat me to it :) Be quite careful when you're removing the intel fan (pictured). It is held in place with screw keys that are disengaged by turning them 90 degrees, and the plastic connectors beneath the motherboard are quite easy to bend/break if forced (which will allow the black 'plugs' in the motherboard to come free). – James Broadhead Jan 12 '12 at 17:27
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    +1. Based on the question, I don't think it's attached properly. – Shinrai Jan 12 '12 at 17:38
  • I only cleaned and didn't touch the paste, could such difference be because of it because it's huge. – Little Helper Jan 12 '12 at 18:11
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    If you cleaned the dust out, but didnt touch the paste/pad that was there, most certainly this is part of the problem. Proper reinstallation of CPU/Heatsink/Fan requires cleaning the old compound off of the CPU AND the heatsink so both are clean metal again. Typically 100% Isopropyl alcohol, or equivalent cleaning pads/swabs should be used for this. Lesser solutions such as those found in first aid kits or medicine cabinets have impurities that can damage electronics because they are a solution less than 100%. Once clean, apply new, fresh pad or paste according to its instructions. – Paperlantern Jan 12 '12 at 21:11
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    @Paperlantern Anyone selling you something higher than ~90% isopropanol is ripping you off. Once the bottle is opened it draws moisture out of the air until it's only ~90% pure. – Dan Neely Mar 30 '12 at 14:09

Just my approach to clean CPU fan from dust.

  1. Turn off the PC

  2. Disconnect CPU fan

  3. Turn on the vacuum cleaner

  4. Put sucking end of vacuum cleaner tube near the inlet of the CPU fan

  5. Allow CPU fan to spin in reverse for a while and go few rounds to pick up dust from all parts of the fan and radiator underneath

Works perfectly with Intel Core Duo fans. Does not require removing CPU, applying grease nor triple checking if fan sits tight.

I know this is not real answer but piece of advice for the next time.


Thermal paste is VERY important for CPUs and GPUs... it's not typically 24-degrees C different... but a must-have none-the-less. It's more likely that you didn't seat the heatsink/fan combo correctly. (sitting at angle... not all 4 posts are seated on motherboard... etc...) As a tip... remove the heatsink/fan combo by turning the black pegs 1/4 turn then pulling them up. they should pop up fairly simply. (don't force them... ) After removing the heatsink/fan... apply a dab (1/2 pea-sized-ish) of thermal paste... (don't go for cheap white paste... get some good stuff like artic-silver) and spread it around. Don't put gobs of the stuff on there... as you don't want it to go places beyond the CPU... you just want enough to cover the cpu and not ooze over the edges. To re-attach the heatsink/fan... make sure all 4 posts are in their upright position... turn them back the 1/4 turn to the locked position... line up the white pastic bits with the 4 holes on the motherboard... and push down until they lock in place. Make sure the peg goes through the hole... and the plunger locks in place. It should be locked rigidly in place for each post. (no wiggle room)


First rule of thumb. Always clean and replace thermal grease when you reattach heatsink. If your heatsink comes with thermal pad, besure to remove them before apply thermal grease. For instruction on how to apply thermal grease, please see http://www.tomshardware.com/reviews/cooling-air-pressure-heatsink,3058-9.html

But if you really want to lower your CPU temperature, then I suggest you buy a new heatsink. Stock heatsinks aren't very good at cooling your CPU to "your satisfaction"

If you don't know where to start for your heatsink, try here http://www.tomshardware.com/reviews/cpu-cooler-heatsink-roundup,2788.html

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    I have found that these models of heatsinks (since core2) have been quite adequate at keeping my chip cool. The days of stock heatsinks being insufficient during the Pentium4 days are past :) – James Broadhead Jan 12 '12 at 17:29
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    How do you know what his satisfaction is. Stock heat sink / Fans are designed to cool the processor adequately under all loads, per manufacturer's specs. Aftermarket ones are for people overclocking and doing very heavy CPU intensive work. Stock CPU coolers are like all weather/all season tires, perfect for the everyday driver. There are other tires for enthusiasts. Aftermarket coolers are for enthusiasts. – Paperlantern Jan 12 '12 at 17:31
  • @ James Broadhead, please don't get me wrong, I didn't say that stock cooler provide insufficient cooling but just not to "your satisfaction" For example with stock cooler, the idle temp is around 40-50C. Which is OK for the CPU. But with better cooler, your idle temp could be around 25-30C. I just feel happier to see my CPU run cooler. That's all. – chmod Jan 12 '12 at 17:37
  • Agreed with the comments - these heatsinks work fine for 95% of users. – Shinrai Jan 12 '12 at 17:41
  • It sounds like the author tried to use the same thermal cooling pad. Once the removed from the cpu, the pad as to be replaced, you can purcase replacement thermal cooling pads or thermal paste. – Ramhound Jan 12 '12 at 18:05

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