T43 cooling issue

[lukee]

My T43 started to reproduce cooling issue, mainly when using it with Linux. System sometimes shutdown automatically, not immediately, but proper shutdown by shutdown command issuance - however automatically. Once the ThinkPad is turned on again, I can see in the logs that CPU reached 100deg Celsius. I need to say that my ThinkPad has modified heatsink/fan - I have removed old fan because of crackling sound and installed new Toshiba fan from eBay (swapped the fan but heatsink module remained same). I have realized that this new fan is a bit thicker than the original fan, but its size allows to install it properly in the 15" shell. From the heatsink I needed to remove the foam on the heatsink corners and stickers which are probably sealing the gaps between fan, heatsink and shell. Question is, if this missing foam and stickers may have some impact on the airflow in the shell and if these can cause the overheating issue?

[Hans Gruber]

No, the foam and stickers have no bearing on your cooling. I suspect your replacement fan is ineffective and cooling your T43. Is your Thinkpad fan running at full power? Is it working hard or hardly working?

[lukee]

Yep, new Toshiba fan is blowing nicely and silently. I would say with the old fan the air which was outleting from the ThinkPad was much more warm and this new fan is blowing a bit longer time only cool air (until computer is fully booted), then it will start to warm the air slowly.

[RealBlackStuff]

Probably your fan-chassis is not making proper contact with the CPU.
Remove the fan, clean up, then apply fresh thermal paste.
Run a few minutes.
Remove the fan again and check that the paste is evenly distributed on both CPU and fan and shows the same rectangle shape.
If not, there's your culprit.
If OK, clean again and apply fresh paste once more, to avoid air bubbles.
Put fan back in.

[lukee]

The problem was probably the new Toshiba fan and its thickness causing the heatsink was not in the correct contact with CPU core. I used old heatsink with old fan, and I can feel warm airflow from the heatsink almost immediately after ThinkPad boots up. As the old fan produces some interference sound, I will probably need to drill a hole at the bottom of the fan in order to prevent fan shaft contact with the fan body.

[Norway Pad]

I will probably need to drill a hole at the bottom of the fan in order to prevent fan shaft contact with the fan body.

Is this the fix that was invented some years ago? I think I remember the conclusion from back then is that the bottom center part, that you drill out, is actually a thrust bearing, meant to hold the axle up. So it's meant to be there, but apparently that fan works without it. If the fan is worn and makes excessive noise I guess there is nothing to loose by trying this. But several users advised against doing this mod on good working fans just as an attempt to make them quieter.

FWIW, just my input on the matter. I have never done this, as the noise from my T43 fans has never bothered me.