Strange CPU overheating problem

The stock heatsink for an Intel Core 2 Duo E800 has been working perfectly for my rig for the last 6-7 months of running it. Over the 6-7 months I went from an idle 50-51 degrees celsius to a 64-65 degrees celsius. The most logical reason I came up with was that the heatsink was coming loose due to movement of the tower and I simply needed to reposition it.

So, I attempted to reposition it, and now it seems impossible to retain a good connection. I thought since I had taken the heatsink off a couple of times, the thermal paste probably wore off a bit. So I went down to the local parts store and picked up some Antec Silver 5 and cleaned the CPU/Heatsink and re-applied the new paste, with no effect. The CPU is still overheating. I've had the push pins down so tight that I couldn't even budge the heatsink, and from what I could tell by the matching texture created by the thermal paste on the CPU and heatsink, the connection seemed fine.

One more note, recently my hard drive failed for an unknown reason. It simply died while my computer was idle and I had to replace it. I still don't know why this happened, but I'm just throwing it out there.

I don't know if this is still a heat problem or possibly something else. Can a heatsink actually break? When I put my hand over the fan on top of the heatsink I don't really feel hot air coming out. That of course might signal a bad connection, but I'm at the point to where I'm willing to bet money my connection is pretty solid. Why all the sudden would a heatsink that's been working for so long just fail? It leaves me to think the CPU is overheating for another reason, but I have no way of telling.

Has anyone ever had a problem like this before?

How did you clean the TIM off? Hopefully with some 91% Isopropyl Alcohol. Anyways, the Intel HSF units are pretty crappy. If I recall correctly your particular unit does not come with a back plate or retaining arms, but uses snap clips correct? That's a large part of the problem since the snap clips will slightly stretch and give you a loose connection. Also depends on how you applied the TIM. Did you use a grain of rice sized drop in the middle and then use a credit card or your finger in a plastic bag to smooth it over the surface? Or did you cake it on? Also check the fans speed via BIOS to make sure it's even moving air, you can add some lubrication there and clear out dust in between the fins. But really, aftermarket heatsinks are so cheap now that's usually going to be the best alternative.

Over the past 6-7 months it transitioned from winter to summer in the northern hemisphere. Depending on where you are located, a 10-15c increase in temperature could easily be caused by a rise in the ambient temperature around the heatsink.

Harddrives fail often and is probably not related.

Heatsinks operate using physical principles of thermodynamics... the laws of physics don't break. If you have a solid connection between the heatsink and the processor it will conduct heat forever, it's simply is not physically possible for its heat conductivity to "break".

I completely agree with E-Oreo, an average 5c room temperature increase can do a lot to the temperature of your system. 6-7 months is also enough time to reduce your cooling fan efficiency with dust and smoking around the computer doesn't help it either. The heatsink is not where you should be looking for a fix in your case.

What I'd do is clean your fans, and make sure there's no dust blocking the ventilation holes in your case. Hot air has to go somewhere. If you already clean your fans regularly, you can get another fan. The choices are up to you however. You can get a good CPU fan which would pretty much be able to cool your entire case effectively (just make sure you have enough space in the case before you buy it), or you can get another case fan which is cheaper but will not help as effectively.

Stock cooling can be a bit funny, and it's far from a perfect solution. I've been using stock cooling on my Intel Core2Duo E6850 and it was not recommended to put the small heatsink fan on if it's not needed, because it would "disrupt airflow" from the stock CPU fan sitting right next to it. Watching the idle temperatures for a bit I decided to ignore the warning and put the heatsink fan on anyway, mainly to ease my mind. It's helped my CPU temperature by quite a bit, despite the warning saying it would reduce efficiency.

A 15*c increase should not have to do with the seasons unless he's not running any AC. And this is coming from a guy who goes from 30-117* in a year with 4-6 PCs running 24/7 in the same room. I can see a 7-8*c bump, but almost 15*c tells me something has been off, especially when 50*c idle is overly hot for that chip as is unless he's pushing more volts through the chip. Normally your CPU is 10-15c above ambient pending on the chip.

But according to him on another forum I'm on, he said he's going to replace the PSU, HS, and case.

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