Hi,

I bought a brand new High Flow sensor and I tested it in a test loop. I noticed that it makes a quite loud ticking noise.
I placed it horizontally as suggested in other threads and reserved the flow, the it doesn't help at all. Even at 100l/h I can still hear it ticking and at 300l/h it's horrible.

Are they all like this, do they need to break in or am I just unlucky?

I opened it and it was spotless inside. After assembly it's still sounding like it was before.
Something is noticed was that the impeller has quite a bit a play on the shaft, but I'm not sure if it's supposed to be like that.

Thank you for the suggestion. I'm comfortable to do this, but I'll check with the shop where I bought it first. Maybe they can exchange it before going all this.

The shop can't do anything for me. Watercooling parts that have been used can't be returned and they told me to wait a few weeks because it's probably air build up. If it's still ticking after a few, I can send it in for RMA.
But I rather not wait that long to get it fixed. The sensor is in a temporary test loop with softtubing, so I can easily move it around to bleed the air from it. I'm quite sure there are no more airpockets inside the flow meter and the ticking continues.

I tried your solution to move the shaft up. I was able to take it up by 0.15mm, but then the impeller didn't spin free anymore after screwing down the white top. It spun when blowing on it, but it stopped pretty quick after that. So there was some slight resistance.
Now I'm at 0.05mm over stock height and the impeller spins free when blowing on it. I ran it again with water in my test loop, but the ticking noise is still there and it didn't improve.

Here is a video of what is sound like: https://www.youtube.com/watch?v=Fs8TQpijsDE&feature=youtu.be

Thank you for the suggestion. I will try that this evening.

Zitat von »Stephan«

I heard the video several times and it is hard to classify the amplitude of the noise. The sensor shold be silent but not noiseless. It looks you have already adjusted the play between the needle to a perfect value. If there is still strange ticking noise it must be something different.
Most common is still dirt inside the sensor but as you have already cleaned it this shouldn't be the issue.

Somehting that also could work is to achieve a more fixed position of the rotor center by doing the folllowing:

1. Disassemble the sensor from the loop.
2. Open the sensor housing and remove the sensor cover.
3. Blow inside the sensor and recognize the sound. The sensor should move up and down while turning.
4. Apply force at the rotor in direction of the axis (approx. 10N ~ 2lbs). Then turn it 20-30 times left/right by 180°.
5. Blow again in the inlet side and check if the sensor is rotation now more smooth and not tunring up/down like before.
6. If still the same noise try step 4 again
7. Adjust the play between axis and rotor like you have already done

Bingo. This fixed it.

I did step 2 times at first. It was still ticking quite loud, but it was a bit better than before.
Then I repeated step 4 about 4 times more since there was progress. The impeller didn't want to move upwards anymore while blowing on it. But when it was coasting after blowing, it ticked always as the same RPM. Then the impeller went of balance at that RPM.

Anyway, then I readjusted the pin height. I got moved it up by 0.1mm. I was now about 0.15mm higher than stock height.
I think this is perfect height. With the screws half tight it spins free. When I tightend them 1/8th of a turn more, it was still spinning when blowing on it, but it didn't coast that free anymore. So I backed out the screws again with 1/8th of a turn to the point where is was free spinning.

Then I hooked it up again and let it bleed for half an hour. Now it's pretty silent. I can still hear it ticking and slightly scraping but I have to listen closely. If I sit 80cm away from it, I can't hear it above my pump. So I guess that will ok once it's build into my case.

Thanks a lot for the help!

Zitat von »mattlach«

In my experience with mine, and others that I have read, this is pretty typical during and right after initial fill.

Within a few days of running, usually all air works its way out of the system, and it quiets down.

At least I think that is what is happening.

That wasn't the case for me. I build a test loop first on my bench with some softtubing. Just a pump, flowmeter, filter and a valve to create resistance.
So I could easily manipulate all parts to get the air out. After 5-10 minutes all bubbles were gone.

This was the fix for me: https://forum.aquacomputer.de/weitere-fo…ng/#post1444319
I could hear that it was fixed 5 minutes later.

I agree that it's hard to bleed once it's build in in a computer, but that wasn't an issue for me.