Weird noise from DC LS720 pump

[Muffin.]

Hello,

 

So I recently built a new rig and it's the first time with AIOs for me and there is a weird sound coming from it's pump from time to time.

I tried to record the sound but all I was hearing in the phone was just fan sounds.  The sound isn't loud, but when I'm not on headphones I can hear it and it bothers me a bit.

• Cooler - DeepCool LS720;
• Mounted like this:

 

From what I've read now, it's normal for AIOs to have some air in them. I understood now that it's from air in it, what's causing the noise from time to time. So basically when air reaches the pump in the circle, the sound appears, it stays for a moment and I guess then the air finally get's through the pump and the sound disappears and so on.

I tried to slightly tilt the PC when the sound appeared and I heard like a liquid or air bubble noise as like the bubble then instantly went through the pump and the sound disappeared. Would be cool if that was a permanent fix, but as it circulates, it reaches the pump again and the sound for a moment is there again.

 

So the question - is there a permanent fix for this or I just should be unbothered about the sound appearing from time to time? I know that some people have the pump sounding much worse, when mounted incorrectly, but I have it mounted properly.

[RevGAM]

As far as I can tell, you have the rad mounted on top, so that's ok but you've got the tubes coming out of the bottom of the water block, which will result in air getting trapped in it. Flip the block over or at least turn it so that the tubes come out of the right side. That will keep the air from getting trapped in the block and causing the eventual burn out of the pump. 

[Muffin.]

On 2/22/2024 at 3:21 PM, RevGAM said:

As far as I can tell, you have the rad mounted on top, so that's ok but you've got the tubes coming out of the bottom of the water block, which will result in air getting trapped in it. Flip the block over or at least turn it so that the tubes come out of the right side. That will keep the air from getting trapped in the block and causing the eventual burn out of the pump. 

Will try flipping the block over next week and give an update. Thanks for the input

[PROZACTv]

On 2/23/2024 at 3:51 PM, Muffin. said:

Will try flipping the block over next week and give an update. Thanks for the input

I have the block the same way as your photo and i can hear the pump making noise, let me know pls if flipping the pump to the right helped with the noise.

[NorKris]

having the pc laying flat for a day or 2 might help 

[RevGAM]

2 hours ago, PROZACTv said:

I have the block the same way as your photo and i can hear the pump making noise, let me know pls if flipping the pump to the right helped with the noise.

Turn the water block so the tubes are on the side or top, see if that helps.

[PROZACTv]

18 hours ago, RevGAM said:

Turn the water block so the tubes are on the side or top, see if that helps.

This is the best way to mount the block? left or right?

[NorKris]

5 hours ago, PROZACTv said:

This is the best way to mount the block? left or right?

tubes towards the ram for looks,  up for less air in the "block" 

[RevGAM]

7 hours ago, PROZACTv said:

This is the best way to mount the block? left or right?

Top is best.

 

Some blocks have the tubes offset on one side instead of centered. If they're centered, then left or right doesn't matter. If they're offset, then whichever side puts them higher.

[RevGAM]

2 hours ago, NorKris said:

tubes towards the ram for looks,  up for less air in the "block" 

Do the tubes have eyes?

[NorKris]

2 hours ago, RevGAM said:

Do the tubes have eyes?

u wooot mate? 

[RevGAM]

34 minutes ago, NorKris said:

u wooot mate? 

You said the "tubes towards the ram for looks", right?

[NorKris]

2 minutes ago, RevGAM said:

You said the "tubes towards the ram for looks", right?

F in chat for bad jokes   

[Muffin.]

Okay. Sorry for the long delay, I was just waiting for my pwm/argb hub to arrive and then work with the PC rather than having to work with it 2 times (pump, then mess with hub). 

To the point -> I guess it's maybe better? I guess the sound now disappears a bit quicker than it did, but it still comes up randomly and then goes away after secs.

I managed to capture the sound it makes and also a pic how I have it mounted now.

• Pic:

• Video (better on headphones, the sound appears at around 6sec. Some talking in the background, sorry, but for a split sec you can hear how the sound appears there): https://streamable.com/hne2zr
• Also for others I can suggest removing the pre-applied thermal paste and apply new one on your own. I ain't no pro, but this doesn't look like enough:
  
  
  

[RevGAM]

18 minutes ago, Muffin. said:

Okay. Sorry for the long delay, I was just waiting for my pwm/argb hub to arrive and then work with the PC rather than having to work with it 2 times (pump, then mess with hub). 

To the point -> I guess it's maybe better? I guess the sound now disappears a bit quicker than it did, but it still comes up randomly and then goes away after secs.

I managed to capture the sound it makes and also a pic how I have it mounted now.

• Pic:

• Video (better on headphones, the sound appears at around 6sec. Some talking in the background, sorry, but for a split sec you can hear how the sound appears there): https://streamable.com/hne2zr
• Also for others I can suggest removing the pre-applied thermal paste and apply new one on your own. I ain't no pro, but this doesn't look like enough:
  
  
  

There's no need to reapply the paste. You don't need a lot - you just need the whole surface of the CPU to be covered with a thin layer that fills any gaps. That looks really good, and even pressure, too.

 

I barely heard anything with 100% volume, but around 7 seconds I heard a mild noise that sounds like the impeller. Nothing to worry about. Good job!

[NorKris]

very nice, now lets talk about  the fact that radiators should be intake  

[Muffin.]

7 minutes ago, RevGAM said:

There's no need to reapply the paste. You don't need a lot - you just need the whole surface of the CPU to be covered with a thin layer that fills any gaps. That looks really good, and even pressure, too.

 

I barely heard anything with 100% volume, but around 7 seconds I heard a mild noise that sounds like the impeller. Nothing to worry about. Good job!

So that's a normal sound from time to time? It's not like it stays there, it just randomly comes up for a moment and goes away.

I did reapply the paste however, I though that was too little

[Muffin.]

1 minute ago, NorKris said:

very nice, now lets talk about  the fact that radiators should be intake  

It's a top mount, why should it be intake 

[NorKris]

3 minutes ago, Muffin. said:

It's a top mount, why should it be intake 

why would u use as cold air as possible to cool?  

[RevGAM]

10 minutes ago, Muffin. said:

It's a top mount, why should it be intake 

What Kris means is that you want the coolest air going through the radiator to neutralize the internal temperature as much as possible. If you use case air, you'll get less of a cooling effect because of all the heat sources inside.

[Muffin.]

3 minutes ago, RevGAM said:

What Kris means is that you want the coolest air going through the radiator to neutralize the internal temperature as much as possible. If you use case air, you'll get less of a cooling effect because of all the heat sources inside.

Ahh, yeah, makes sense, not sure why I didn't do it like that initially. At some point I might switch it, thanks

[Muffin.]

32 minutes ago, RevGAM said:

There's no need to reapply the paste. You don't need a lot - you just need the whole surface of the CPU to be covered with a thin layer that fills any gaps. That looks really good, and even pressure, too.

 

I barely heard anything with 100% volume, but around 7 seconds I heard a mild noise that sounds like the impeller. Nothing to worry about. Good job!

So that sound is normal, no need to worry?

[NorKris]

18 minutes ago, RevGAM said:

What Kris means is that you want the coolest air going through the radiator to neutralize the internal temperature as much as possible. If you use case air, you'll get less of a cooling effect because of all the heat sources inside.

he might mean this  

[RevGAM]

9 minutes ago, Muffin. said:

So that sound is normal, no need to worry?

Correct.

[Muffin.]

Alright. Thanks for all the input from you all, appreciated.