Corsair XD5 Pump Noise Grinding

[mk1_salami]

I'm having a bit of trouble with the XD5 model pump from Corsair. Those who followed my other thread might have seen that I replaced my XD3 for a D5 based XD5. I bought an XD5 from OCUK and it was making what I can only describe as a grinding noise. Think of a really old mechanical HDD at full chat, but louder.

I reached out to OCUK support who were helpful and arranged for me to return the pump for a refund. I went ahead and bought another XD5 and it's even worse! To be clear- during the prime process the pump never ran dry - not even near. I've included a video. Anyone ever had this? I really don't want to get a third pump and find I've got the same problem! As you can imagine, it's a complete PITA replacing a pump on a hardline loop. I've searched online and there are a few similar posts about this pump but the threads go cold - I'm not sure if they fixed it or not.

Under 70% the pump sounds like you'd expect, a quiet hum. At ~70% the grinding starts, 80% it goes away and at 100% it's unbearable to sit next to.

I actually stripped down the pump/res and had a look inside the pump. All looks ok to my untrained eye, and there's no debris in there.

Any ideas?

 

[GoRedwings19]

I wanted to get that pump as well. As I wanted to start watercooling. Think I will stick to my AIO

 

[mingey]

I have a couple of D5 but unless I'm getting rid of air bubbles at full whack it's silent although I run them at 35%, unless it's a really restrictive loop I wouldn't go much higher than 45% really not needed in my loops, as an of chance have you tried seeing if that grinding noise is at all related to vibration at all?

 

[wookiee87]

jeez your not having much luck with your loop, grinding like that usally means a couple of things. Either small debris have entered the pump and something is lodged between the impellar and housing, low rpm's it can work fine but as rpm's increase the impellar wobbles as it spins faster.

Or there are micro bubbles trapped in the pump area, and the solution to that is ramp the pump up and down (20-30 seconds at 100% then down to 30-50% for a few more seconds) whilst tipping the computer back and forward, after a few minutes and with any luck the pump will stop making any grinding noise what ever speed you run at.

What coolant are you running too, hopefully not pastel based one, as they arnt great for long term use (normally around 6 months before a flush is needed) if you dont you risk sedimentation of the uv element in the cooling liquid, any of that goes into the pump, well it may explain the sounds your hearing

if the above doesn't sort its self out, look at a ek d5 pump/res combo instead, i've used many over the years and have had no issues.

 

[Bubo]

It sounds to me like it is going through two resonant frequencies, one at 70% and another at 100%. I don't think it will be to do with debris stuck in the impellor, I think it will be either the impellor rattling on its bearing at these two speeds. or the pump hosing or mount. If you are not familiar with resonant vibration, then basically everything, literally everything on the planet, will have a fundamental resonance frequency determined by the mass and stiffness of the object/assembly, which if you have a driving cyclic frequency, i.e. your pump running at frequency X, that matches a resonant frequency of some component, then you are going to get resonant vibration, which can be severe especially if the pump speed exactly matches any resonant frequencies you have in your set up. This is almost certainly why it drops as you go through 80%, as that pump speed probably no longer hits a resonant frequency in your set up at that speed. The resonance can be coming from the pump impellor itself, or also the mounting arrangement. You can test for resonance by setting the speed to one which has the resonance, then disturb the stiffness of the assembly by gripping the res and giving it a slight pull sideways. Doing this will change the stiffness of the assembly and thus will change the resonant frequency. It it doesn't change then it is likely to be the impellor resonating, which there is not much you can do about if the sound stays. But, I would guess pulling on the res will change the sound, and if it does then it will be a case of how you go about providing that change in stiffness without you sitting there holding the res. This may be something as simple as loosing the pump mounting screws, or even tightening them up more, or wedging something under the mount etc etc. Anything which will change the stiffness of the assembly.

Another source of grinding type noises in pumps is cavitation, but I doubt a small pump like this will be running fast enough to cause this. Cavitation in proper big metallic pumps can cause serious damage to the impellr.

 

[mk1_salami]

I thought I might see some debris in the pump and that's why I dismantled it. Nothing to see in the pump to my untrained eye. The 'hat' is just held on with a magnet and it spins freely.

There are actually quite a few posts online of the same noise from this pump/res.

 

[Mcnumpty2323]

Bubo probably mentioned something similar
But his reply is too big a block of text
I can't read those very well

At certain rpm my ek d5 combo resonates
Around 70% and over 90%
Though not to anywhere remotely that extent /loudness

Have had an imbalanced impeller before
And that acted differently
It rattled at all rpms just got worse/louder the faster it went
Replacing the impeller totally stopped that

Guess your choices are run it at an rpm it doesn't do it
Or replace it
Or try some sort of dampers like rubber washers maybe
If holding it with your hand stops the noise
that might be an option
no real need to go flat out with a d5 usually

Was probably me suggested your original choice pump
Might not be man enough
So apologies for all the hassle you're having mate

 

[SirConfused]

Watching that video definitely sounds like resonance to me. Sorry to hear you're having such trouble with the loop but as others have said, you shouldn't need to run the pump at such high speeds tbh. I've never needed to run my d5 past 50% other than when I'm filling and trying to get air out so it's up to you on whether you live with it and don't use it at those speeds or try and find a better damping solution to cut out the issue.