Overheat caused by uneven thermal grease?

This is probably a really easy question and I'm sure I already know the answer, but here goes:

I just finished building my first computer from scratch with the help of some more knowledgeable friends, and before I managed to boot it up for the first time, set up the BIOS, and install Windows, the heat sink fell off the processor.  I reattached it but did not apply a new layer of thermal grease, and started the system.  A dumb move, I'm sure, but I'm learning as I go.

The computer is now up and running, but the CPU is constantly idling somewhere between 40-50 degrees Celsius, spiking massively when I run programs, play video files, load DVDs, etc.  When I run minor programs, it usually hovers around 50-60 degrees, but it sometimes rises above 80 with no sign of stopping.  When this happens, I immediately exit all programs and the temperature drops fairly quickly.

Is this overheating issue most likely caused by uneven thermal, and will removing the existing grease and applying a new layer fix the issue?  It seems to me that if it were, my CPU would be idling even hotter, but I'm not an expert, which brings me here.
Who is Participating?
Gary CaseRetiredCommented:
Yes, your problem is clearly caused by inadequate contact between the CPU and heatsink.

You need to (a)  remove the heatsink;   (b)  clean off all thermal compound from both the CPU and the heatsink [scrape what you can with a credit card;  then use a clean rag with isopropyl alcohol to clean the rest -- waiting until everything is completely dry before proceeding];  then (c)  carefully apply a very small uniform amount of thermal compound to the processor and re-mount the heatsink -- being sure you mount it securely.

You should then have much better performance -- and no overheating.
did you put thermal grease on the first time, or was it a thermal pad on the heatsink?
normally (in my experience) if it is not used for long, just check if it is evenly spread, and reeattach the sink.
check that it does NOT touch any contacts !(wuith newer CPU's less probable)
no new paste required imo -
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.