Question Normal AIO cooler pump sound or trapped air bubbles? (Kraken X62)

Oct 3, 2019
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Hi, just assembled my latest build with a Kraken X62 and I've noticed the pump is quite loud when all of my case fans are using silent profiles. After doing a bit of research online I've learned about trapped air bubbles in the loop causing this issue. However I'm struggling to decide if what I have is just the normal sound of the pump or indeed trapped bubbles? I recorded the sound at the link below to get other people's opinions on it.

View: https://www.youtube.com/watch?v=FVNZt4DdwF0


I've read conflicting stories online about specific radiator orientations causing air bubbles to get trapped in the wrong places. At the moment I've propped the pc case up at the front to see if that helps which you can see in the video. Anyone any experience with that helping things?

Any input would be appreciated - the sound is pretty annoying.
 
Oct 3, 2019
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I've noticed some people are able to hook up their cooler to a power supply outside of the case so they can play around with it to adjust the noise. Do you know how they do that? I mean if the cooler is off the CPU, the PSU won't turn on, right?
 
Oct 3, 2019
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You may be able to unplug the cpu plug or plugs if you are using 2.
Then hit the switch the cpu wont have power to fire up but all the other parts should if what you are thinking of doing is run the pump for awhile and not having to worry about the cpu.

Yeah, that's exactly what I'm thinking. I had no idea the PSU would let itself turn on with the CPU plugged out.
 

rubix_1011

Contributing Writer
Moderator
I would refrain from recommending to 'squeeze the hoses'.

Some AIO liquid coolers have an internal sleeve that is designed to help prevent leaks and evaporation, but also is a bit rigid and can crack and separate, causing permeation of the tubes.

So, please don't provide this information...tipping/tilting and moving the case or the radiator can often offset this. It sounds like you might have a partial airlock or just cavitation of the impeller and is making a gurgling sound.
 
Oct 3, 2019
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I have not been able to improve the sound. My only remaining option (other than to ignore it) is to remove the cooler and try test it outside of the case in different orientations. However I want to refrain from taking the whole thing apart because I finally got the cable management where I want it and it took ages.

If anyone knows if it's possible to disconnect the cooler from my CPU but keep it connected to my PSU which is still in the case, please let me know. Then I could try fix the sound by moving the cooler and radiator around without having to take the whole build apart.
 
Hi
It's me again with a little less to sit on. LOL
Lesson learned.

It looked like you had a big droop in the hose's maybe it needs some gravity feed to the pump.

So can you take the rad and fans attached out of the case so it can still run?,
If so try putting it say in a position as if it was installed up top in the case.
You would have to find away to prop it up.
Maybe on a small waste basket so it can still get air.
 

Karadjgne

Titan
Ambassador
Best option would be to complete what you started. Your hoses are in a strong U shape which can sometimes impede air movement along the line, especially if the pump is already cavitating and can't build enough pressure.

1. To alleviate this, with the pc running, continue to tilt it very slowly, until the rad is above the pump and hold it there until the noise goes away totally plus a minute or until its been more than long enough that something should have happened by now.

2. At that point, shutdown the pc, with it remaining upright, and wait a few minutes, then restart.

3. If that doesn't clear the pump, shutdown, give the pc a small shake, restart.

In all the years of messing around with liquid cooling, I've only done stage 2 once, every other time the pump clears naturally in stage 1 within a few seconds. Never needed to get to stage 3.

If all that doesn't alleviate the noise, imho there's something more going on than a bubble in the pump.
 
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Oct 3, 2019
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Best option would be to complete what you started. Your hoses are in a strong U shape which can sometimes impede air movement along the line, especially if the pump is already cavitating and can't build enough pressure.

1. To alleviate this, with the pc running, continue to tilt it very slowly, until the rad is above the pump and hold it there until the noise goes away totally plus a minute or until its been more than long enough that something should have happened by now.

2. At that point, shutdown the pc, with it remaining upright, and wait a few minutes, then restart.

3. If that doesn't clear the pump, shutdown, give the pc a small shake, restart.

In all the years of messing around with liquid cooling, I've only done stage 2 once, every other time the pump clears naturally in stage 1 within a few seconds. Never needed to get to stage 3.

If all that doesn't alleviate the noise, imho there's something more going on than a bubble in the pump.


In the video I had it propped up already and it didn't improve the sound. However I did this very quickly and not slowly.

Is the key thing to do it very slowly? Also, is how I propped it in the video look ok? I could try that propping method again but much slower...
 

rubix_1011

Contributing Writer
Moderator
If you can dismount the radiator from the case and let the system boot up, you can tap and tilt the radiator to see if that helps, but also straighten the tubing and tap the pump unit.

Provided that the AIO should be mostly filled with coolant, there isn't a lot to the 'gravity' fed part of the cooler since you are displacing coolant with coolant. This would be a much larger issue if there is air trapped in the pump, which would prevent coolant movement, and also impact temperatures.

From your video, I don't hear anything, what should I be able to hear? Also, in the video, if you want to rotate your radiator 180 degrees (tubing inlet/outlet down vs. up as you have it) it will cause air to collect in the radiator end tank as you tilt and rotate it. You would rather it collect there than able to be anywhere near the pump.
 
Oct 3, 2019
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If you can dismount the radiator from the case and let the system boot up, you can tap and tilt the radiator to see if that helps, but also straighten the tubing and tap the pump unit.

Provided that the AIO should be mostly filled with coolant, there isn't a lot to the 'gravity' fed part of the cooler since you are displacing coolant with coolant. This would be a much larger issue if there is air trapped in the pump, which would prevent coolant movement, and also impact temperatures.

From your video, I don't hear anything, what should I be able to hear? Also, in the video, if you want to rotate your radiator 180 degrees (tubing inlet/outlet down vs. up as you have it) it will cause air to collect in the radiator end tank as you tilt and rotate it. You would rather it collect there than able to be anywhere near the pump.

Unfortunately there is a flaw in NZXT's H400i case that if you try and mount the radiator with the hoses at the bottom, the dust filter does not fit over the radiator anymore so I'm stuck with this orientation.

The sound you should be hearing is a very faint crackling noise coming from the pump over the CPU. My temperatures are excellent (my i7 9700k is idling at 25C and maxes out around 60C under load), and maybe this is a normal sound the pump makes, but the quiet crackles are definitely audible when all my fans are in their silent profiles.
 

rubix_1011

Contributing Writer
Moderator
Unfortunately there is a flaw in NZXT's H400i case that if you try and mount the radiator with the hoses at the bottom, the dust filter does not fit over the radiator anymore so I'm stuck with this orientation.

...Or just remove the dust filter. This would be my choice outside of not using an AIO to begin with.

Crackling noise is air bubbles as they are moved through the impeller and cavitation occurs. Air will move through the radiator and then reach the radiator outlet tube, where they will continue to zip into the coolant stream, back to the pump. Air rises in water/coolant, so this has the likelihood continue to occur indefinitely.
 
Oct 3, 2019
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...Or just remove the dust filter. This would be my choice outside of not using an AIO to begin with.

Crackling noise is air bubbles as they are moved through the impeller and cavitation occurs. Air will move through the radiator and then reach the radiator outlet tube, where they will continue to zip into the coolant stream, back to the pump. Air rises in water/coolant, so this has the likelihood continue to occur indefinitely.

So you're saying as long as the tubes are orientated at the top of my radiator, cavitation is going to continue to occur? So the best thing I can do now is unscrew the radiator, flip it 180 degrees and see if that makes a difference...and if it does, consider losing the the dust filter in favour of this quieter orientation?
 

rubix_1011

Contributing Writer
Moderator
Yep.

Either you live with the occasional noise or flip the radiator...or mount it to the top of the case. Either way, part of the issue is that any air bubbles making it into the radiator will also have the ability to make a full cycle back around to the pump. Many will collect at the radiator inlet port and hopefully not pull through the radiator, but any air in the outlet tank is able to make their way to the pump impeller.

The only negative side is any noise you hear. This isn't going to impact cooling or cause failure.
 
Oct 3, 2019
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Yep.

Either you live with the occasional noise or flip the radiator...or mount it to the top of the case. Either way, part of the issue is that any air bubbles making it into the radiator will also have the ability to make a full cycle back around to the pump. Many will collect at the radiator inlet port and hopefully not pull through the radiator, but any air in the outlet tank is able to make their way to the pump impeller.

The only negative side is any noise you hear. This isn't going to impact cooling or cause failure.

Okay, thanks for the info. I'll try it the orientation and see if it makes any difference. Might be that there's no change and I'm being pedantic for nothing.
 

Karadjgne

Titan
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In the video, you started the tilt, but not nearly far enough. Basically you'd want the intakes facing straight up. I use a couple of thick books to support the case edges, so it's not resting on the rear wiring connections.

Removal of the radiator and straightening the tubing above the level of the pump as suggested by rubix accomplishes the same thing.

I use the word slowly because most ppl have a hdd that's running, and a slow controlled tilt won't affect it, but a faster tilt and sudden stop can. It's a running pc, they don't like movement, in general.

Noisy pumps can happen. Generally the asetek designs are about the quietest, but occasionally one happens that isn't so quiet. On the plus side, you can hear it running, although it's not always a guarantee that it's actually working.
 
Oct 3, 2019
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In the video, you started the tilt, but not nearly far enough. Basically you'd want the intakes facing straight up. I use a couple of thick books to support the case edges, so it's not resting on the rear wiring connections.

I use the word slowly because most ppl have a hdd that's running, and a slow controlled tilt won't affect it, but a faster tilt and sudden stop can. It's a running pc, they don't like movement, in general.

Okay, I can try give that a shot. However, is this the kind of thing where you have to keep it in that position for a few days, or would you expect a few minutes to be enough?

EDIT: Few minutes holding it upright didn't make much of a difference in terms of the sound.
 
Last edited:
Oct 3, 2019
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For anyone who is still interested, based on this video...

View: https://www.youtube.com/watch?v=CV1BT5nMkhg&t=283s


...I believe that what I am hearing is a normal (or rather unavoidable) sound coming from my AIO cooler's pump. Based on the video, my pump definitely doesn't sound as loud as the 'loud version' so I can only assume it's actually normal and I'm being pedantic because I can still hear it even though it's relatively quiet.

If you have any additional thoughts, please feel free to share though.
 

Karadjgne

Titan
Ambassador
Are you sure all of the mounting screws/nuts are good and snug? If one is even a fraction too loose, it can be enough to allow sound from the pump vibration.

And no, not pedantic at all, you have a legitimate concern no matter if founded or unfounded. The answer 'it is what it is' is pretty common, but an exploration of possible fixes/changes and putting doubt to rest is always a better conclusion.
 
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