Alright so my computer was shutting off the other day cause it was getting too hot.
I cleaned it out thoroughly and then it stayed on just fine but I noticed my CPU was still running hot.
So I took the heatsink out, cleaned off all the old thermal paste, blew it out with an air compressor to get all that hard to reach dust.
Put it all back together and on a full load my CPU goes up to 97-99 C instantly.
I cut off Prime 95 and it goes down to 65 in a matter of seconds. I touch my CPU heatsink and it isn't even hot.
It never really got hot before so I don't know but when it was shutting off it was blistering hot.
Point is I don't know if I should just buy a new cooler, I've been using the stock for 2 and a half years and it never gave me problems. Or if maybe the temperature sensor is legitimately broken. It's not hot on the inside and it doesn't run slow by any means, in fact it's been running faster since I blew it out.
I5 750 2.66 Overclocked to 3.2 ghz.
Also if I clock it to normal speeds it still gets crazy hot.
The stock intel cooler is notoriously difficult to mount.
I suspect that your cooler is not warm because it is not in proper contact with the cpu.
To mount the Intel stock cooler properly, place the motherboard on top of the foam or cardboard backing that was packed with it.
The stock cooler will come with paste pre applied, it looks like three grey strips.
The 4 push pins should come in the proper position for installation, that is with the pins rotated in the direction of the arrow,(counter clockwise) as far as they can go.
Place the cooler so that all 4 pins are oriented over the holes in the motherboard.
Push down on the entire cooler so that all 4 pins are through the motherboard.
When you push down on the top black pins, it expands the white plastic pins to fix the cooler in place.
The trick to getting it on is to push down on a diagonal pair of pins at the same time. Then the other pair.
If you do them one at a time, you will not get the cooler on straight.
Lastly, look at the back of the motherboard to verify that all 4 pins are equally through the motherboard, and that the cooler is on firmly.
This last step must be done, which is why the motherboard must be out of the case to do the job.
It is possible to mount the cooler with the motherboard mounted in the case, but you can then never be certain that the push pins are inserted properly.
If you should need to remove the cooler, turn the pins clockwise to unlock them. You will need to clean off the old paste and reapply new if you ever take the cooler off.
Better yet, buy a $30 cooler like the CM hyper212 or Xigmatek gaia. They will keep your cpu cooler and quieter.
The backplate mounting is easier and more secure.