WHAT is overheating my PC?!

[tepsa]

Hello! I know this has been covered so many times, but I have been googleing this issue for about a year now and I cannot find an answer to my problem.

So, as I said, my PC is overheating. I will try and write down everything I have checked and done but there’s a chance I might forget something, since I’ve been dealing with this for such a long time. I will (try to) provide any additional info if needed.

Below are photos of my temperatures and BIOS settings.
I should add that this PC has its original coolers and it didn’t used to overheat for a couple of years. *** It started overheating last year when my son started playing some more demanding games, to the point where PC was shutting down due to the temperature. Even tho he stopped playing them on this PC, the problem just never went away!***

-I have cleaned my PC inside (it’s like a damn pharmacy in there!)
-I have opened my power unit and cleaned that cooler as well
-I have replaced the paste on my CPU and GPU coolers
-I have installed an additional cooler in my tower (not a very strong one, but still)
-My BIOS is the latest version
-I tried turning those “Smart Q-fan” and “Cool ‘n’ Quiet” features on and off - no difference when it comes to temperatures.
-Overclocking is set to Auto, whatever that means (i.e. system default in BIOS). I haven’t played with the overclocking.
-The PC is not close to a heating source. During the winter the situation was bad re temps, but I pulled through. But my PC shut down two days ago after watching a YouTube video (NOT fullscreen!) after 17 minutes. And it’s only spring here. Can’t imagine what the situation will be in the summer!

Pics from my BIOS
https://drive.google.com/file/d/0B3OtMmy96PwoZU4yVFk1X0haNlU/view?usp=sharing
https://drive.google.com/file/d/0B3OtMmy96PwoSEFvWmpCUmt5SDA/view?usp=sharing
https://drive.google.com/file/d/0B3OtMmy96PwoRWZ1T1BQNkpwLU0/view?usp=sharing

Pics of the temperatures:
1. Temps at the start (in the morning after it has been turned off thru the night) https://drive.google.com/file/d/0B3OtMmy96PwoQUFBdzVtMEpnZWc/view?usp=sharing
2. Some mid ranges https://drive.google.com/file/d/0B3OtMmy96PwoR1pzT0QwZ0ljMHc/view?usp=sharing
It gets worse than this. Yesterday I saw Core1 getting to 100C. It didn't shut down then yet.

Oh and also I did some GPU test a while ago but these numbers don't mean anything to me
https://drive.google.com/file/d/0B3OtMmy96PwoM1VQZGhkZkQtYjA/view?usp=sharing

OK I cannot think of anything else to say right now.
Is it possible that the GPU is heating up the whole system? I cannot control its fan’s speed (or at least I dunno how).

Any ideas are welcome! Thank you.

 

[GhislainG]

Based on the motherboard temperature and presuming the ambient temperature is 25°C or less, your case doesn't seem to provide very good airflow. I would try setting the full speed temp lower than 70°C, but that may not help much; enabling Cool'n'Quiet should keep the CPU a bit cooler. Make sure you have good airflow in the case (one inlet fan that pulls cool air in the front and an exhaust fan that expels warm air in the back). I would also suggest you re-install the CPU cooler. Clean the old thermal paste, apply new paste like AS5 and spread a very very thin layer using an old credit card or something similar. Applying too much thermal paste isolates the CPU from the cooler.