Question Rising CPU temperatures in idle

[djhz2001]

Hello,

I have encountered an overheating problem with my desktop PC, and I was hoping I could get some help figuring out what the problem is. I just moved into a different apartment. In my new apartment, I am experiencing high CPU temperatures (this was not the case before I moved). My PC uses the following components:

• Case: Corsair Vengeance C70 ATX
• CPU: i7-6700K (running at stock multiplier)
• CPU cooler: Lepa Aquachanger 240 (liquid cooler)
• MSI Z170A GAMING M7 ATX LGA1151
• Memory: G.SKILL Ripjaws V DDR4 3000 C15 2x16GB
• Boot drive: Samsung 960 Evo NVMe PCIe M.2 500GB
• Power Supply: Corsair RMx 750 W 80+ Gold
• Videocard: Nvidia GTX 1070 Founder's Edition

The symptoms and simple troubleshooting that I have done so far are as follows:

• When I enter Windows 10, the liquid cooler fans spin faster than usual. Temperature is also slightly higher than usual (45-50C, normal temperatures were 30-40C before I moved).
• When left idle for a while, CPU temperature has climbed to 75-95C. Opening the case does not affect the temperature.
• When using the PC for extender time periods, the PC becomes slow and eventually freezes. When rebooting, the PC is still slow, CPU temperatures start high (75+C) when starting windows.
• In one instance, I saw a black empty screen when I rebooted after the PC after it froze, and it did this for the next three reboots I did shortly after (the pump casing was hot to touch after rebooting). However, the PC started normally after I left the PC off for several minutes and the CPU temperature was 45-50C. This temperature slowly climbed over time while idle. Opening the case had no effect on CPU temperature (it kept climbing).

I am thinking that perhaps my liquid cooler is failing. However, since I am not sure of this, I was hoping to get a few other opinions on this. Thank you for your input in advance.

 

[86zx]

How long have you had the cooler?

 

[Stackimaginable]

Temperature is also slightly higher than usual (45-50C, normal temperatures were 30-40C before I moved).

The ambient temperature being higher will increase overall system temps, just be aware of that.

Did you check when you moved that all components are correctly seated and that nothing has come out of place.

Also make sure there isn't a dust build-up anywhere in the radiator or fans (or anywhere for that matter.)

As mentioned above, depending on the age of the cooler, it may have been failing and move might have finished it off.

 

[djhz2001]

How long have you had the cooler?

I have had the cooler for about 3 years.

 

[86zx]

I have had the cooler for about 3 years.

This may seem odd but if you can take the cooler off and give it a good shaking my theory is there’s either a trapped air bubble or some particles blocking the pump from flowing properly. Even if it does work it would probably be a good idea to get a new cooler

 

[djhz2001]

Did you check when you moved that all components are correctly seated and that nothing has come out of place.

Also make sure there isn't a dust build-up anywhere in the radiator or fans (or anywhere for that matter.)

As mentioned above, depending on the age of the cooler, it may have been failing and move might have finished it off.

All components look properly seated.

There is some dust, but it is not terrible since I dusted off the PC relatively recently. I also verified that there is airflow through the radiator. My setup is made so that the air passing through the radiator is ejected from the top of the case, and I compensate for negative pressure inside the case with extra fans on the front and side of the case. I can feel air being pushed through the radiator by both fans when I place my hand on top. Also, the air coming out of the radiator does not feel particularly hot even when the CPU gets hot.

Still it may be a good idea to dust off the PC (tomorrow) and see if the problem persists. I will update you if the problem is solved after doing this.

 

[djhz2001]

This may seem odd but if you can take the cooler off and give it a good shaking my theory is there’s either a trapped air bubble or some particles blocking the pump from flowing properly. Even if it does work it would probably be a good idea to get a new cooler

I could try this, but if I know that my problem is the cooler, I would rather get a new cooler and forget about the problem, as you recommend. However, do you think this overheating problem be caused by a fault in a different component? And if so, what would you suggest to test it?

 

[86zx]

If there’s no dust in radiator and the fans work fine then it’s either pump failure or a blockage it’s super unlikely that the ihs would not be in contact with the cpu die. The other components aren’t gonna affect cpu temps

 

[geofelt]

Likely your cooler has a problem.
You may have a bad pump, or perhaps a clogged circulation line.
Possibly you have a leak where some coolant has been lost.

I am not a fan of aio coolers.
If you have 160mm available for a good tower type air cooler, that is what I would buy.
A noctua NH-D15s will cool just as well, be quieter, more reliable, cheaper and will not leak.

 

[djhz2001]

If there’s no dust in radiator and the fans work fine then it’s either pump failure or a blockage it’s super unlikely that the ihs would not be in contact with the cpu die. The other components aren’t gonna affect cpu temps

I inspected the radiator for dust buildup on Saturday, and I saw some dust, but it did not impede air flow. I did not have my duster with me, so I was unable to clean it. However, given your and Stackimaginable suggestions that it was likely the cooler that was malfunctioning, I got a Corsair H115i and installed it on Sunday. My temps were lower than they were with the AquaChanger before this issue (23C with 4 google chrome tabs open in a temperate room). Temperatures did not climb over time either, so I guess my problem is solved. Thank you all very much for your help.

 

[djhz2001]

I am not a fan of aio coolers.
If you have 160mm available for a good tower type air cooler, that is what I would buy.
A noctua NH-D15s will cool just as well, be quieter, more reliable, cheaper and will not leak.

Too bad I did not get you see your message before I got my new cooler. Though I must say that the Noctua NH-D15S is massive. I will likely build a new PC with an air cooler sometime in the next two months, but I will probably use a smaller air cooler. Regardless, thank you for the suggestion. I learned that you can get a very good overclock in air coolers as well.

 

[geofelt]

The potential effectiveness of any cooler, be it air or liquid is primarily determined by the size of the radiator.
A normal 160mm air cooler with a 120/140mm fan has about the same radiator size as a 120/140 mm aio cooler.
The main difference is where the liquid to air heat exchange takes place.
Yes, an air cooler has liquid in the tubes. It is simpler and more reliable because the liquid does not need a pump to make it flow.
Similarly, a 240/280 aio cooler has two radiators of 120/140mm each.
That is what top twin stack air coolers like noctua NH-D15s have.
That is why the above coolers can be somewhat comparable.

When you get into 360 aio coolers, that is where you can do better.

Another less understood reality is the capability of the case to deliver fresh air to the cooler to let the cooler do it's job.
Usually, two 120/140mm front intakes are what is needed.
One issue with aio coolers is how to mount the radiator.
If you mount it to take in fresh air, your cpu will be cooled as best as can be.
The down side is that the hot radiator exhaust enters the case where the motherboard and grahics card are fed hot air.

It is catch 22 since if you mount the radiator to exhaust hot air, your motherboard and gpu get fresh air, but your cpu will not be cooled as well as it could be.

As to overclocking, the first limit on how high you can go is the quality of your chip.
Good luck there.
Likely, the next limitation is how high a voltage you are willing to tolerate.
Higher voltage increases the heat in the processor, and that needs to be dissipated.
For the most part, with a good cooler, the oc limit will be the voltage issue.

FWIW:
As of 12/04/2016
What percent can get an overclock at a somewhat sane 1.4v Vcore.

I7-6700K
4.9 5%
4.8 21%
4.7 64%
4.6 96%