Water cooled CPU suddenly getting very high temperatures

Rich A

Distinguished
Apr 5, 2013
8
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18,510
I have a home built PC about 4 years old. It has seen heavy service since then (used a lot of hours) and this problem is the first I've had in four years.

Normally the system is very quiet. CPU temperatures have been at or below ambient room temps. At least I think that's what I remember. I've only serviced it once a year to blow out the dust and such. Never a problem. The system has a Asus Sabertooth 990FX and an AMD FX-8150 8-core processor. It has an AMD closed water cooled system that was sold as a package, the radiator, fans CPU heat sink for the pump etc.

The problem is that now when I turn on the system, all is fine while idling but when stressing the CPU the temps and fan and pump speeds start climbing. As they climb the PC becomes very loud .. like a jet engine.

My monitor is telling me the cooling liquid ranges from 43 C to 49 C while just checking email and browsing.

I've been watching the following:
The CPU fan runs from a low 900 rpm to a high 2520 rpm
The pump runs from a low 2880 rpm to high 3720 rpm.
The liquid coolant runs from a low 38 C to a high 50 C
The GPU temps are always very low like from a low of 26 C to a high of 33 C

When there is maximum CPU use for a length of time (3 minutes or more) all the temps and fans start getting to their high point as above and then after a while the PC just turns off .. no visual or audible warnings etc. Just goes dead. I have to wait a few minutes while it cools and then I can start up normally and temperatures are fine until I stress the 8-core CPU.

I've run a stress test where all 8 cores are at 100 percent. All temps and fans seem to max out at around 55 to 60 C for 3 minutes and then the pc stops. While high, I don't think they are high enough to cause problems.

I don't do any gaming and the only thing is at all stress related might be the high def video streaming I do over the web ie. Netflix etc. When watching Netflix at it's highest quality after several minutes the coolant temp starts to climb along with increasing fan speeds and noise to the point where the pc shuts down. Other applications also cause the higher CPU levels like Video editing etc.

Can anyone give me some hands on experience with a water cooled system and what a bad pump might sound like? This was a CPU / Water cooled system sold by AMD which included the closed water system and CPU and fans etc. As the cpu temps approach 50 C something in the box start to sound like a jet engine. I haven't yet tried to locate which is making the noise. That's next on my troubleshooting. I'm just looking for comments on my CPU use relative to heat being reported. I think I have the bios cpu shut down temp very conservative and this shut down problem happens long before I approach the BIOS CPU shut down temps.

I've already checked and cleaned the radiator, and cleaned the CPU removing all the old heat sink compound with the proper chemicals and replaced it with new artic 5 thermal paste.

This thing has been so trouble free for so long that I've forgot most of the things I originally set it up with. <grin>

 
Solution
Given that both the radiator fan and pump speeds appear to respond properly to the CPU temp (very good detail, by the way!), my guess is that the "sealed" system has actually lost a significant mount of the liquid in it. Either that or the pump internal pars have worn to the point that they don;t actually pump the volume they should. Either way, as n0ns3ns3 says, there's really no way to fix. Just replace.
Most CLC AiOs have a very limited lifespan - they are designed to function 2-5 years. I can guess what happened to it but it's not that important. In most cases there is no curtain way to disassemble them without damaging so fixing such cooler is not that trivial.
IMO, just get new cooler. be quiet pure rock 3 pro for example will keep your system cool and quiet while will serve you many years
 

Paperdoc

Polypheme
Ambassador
Given that both the radiator fan and pump speeds appear to respond properly to the CPU temp (very good detail, by the way!), my guess is that the "sealed" system has actually lost a significant mount of the liquid in it. Either that or the pump internal pars have worn to the point that they don;t actually pump the volume they should. Either way, as n0ns3ns3 says, there's really no way to fix. Just replace.
 
Solution

Rich A

Distinguished
Apr 5, 2013
8
0
18,510
Thanks guys. I can't complain after 4 years of trouble free service. I took a good look at it on the work bench last night and RPM of pump gets pretty high when stressing the CPU. Also the noise is coming from the pump. It's probably a low liquid problem which is going require the whole system replacement. Any recommendations for a new closed loop cooler ?