H100i v2 rattle / grinding noises, two brand new units

[anphetamina]

Hi guys, this week I've got two H100i v2 replacements from Amazon for my broken old unit and I've got the same exact issue with both of them.
I'm 100% sure I installed the AIO in the correct way but they do a super annoying rattle noise coming from the water block or the begin of one of the two pumps I can't say. The grinding noises start when it's set to Performance, i've tried to run the AIO for a couple of hour with the PC on its side or to do little hits with my fingers to the pumps and when I do so I hear "air bubbles" moving. Both units were working as expected, no temps issues.
Did I get two unit from a broken batch or what? My old one, bought last year, never did those noises.

 

 

 

[Tiwaz]

you have to set the pump header voltage to 12V, which is max speed, otherwise you will get the rattling since these pumps wont run properly with less V

[anphetamina]

I've tried disabling the cpu controller or set it at PWM turbo mode, no change

[Guest]

You might have small air bubbles, something similar was happening to my 980 ti hybrid. Tilt the pc (with a book or two) to angle the tubes at the bottom of try and get the air bubbles to top of rad. Do you have it mounted vertically or horizontally?

[anphetamina]

10 minutes ago, Abyss Gaming said:

You might have small air bubbles, something similar was happening to my 980 ti hybrid. Tilt the pc (with a book or two) to angle the tubes at the bottom of try and get the air bubbles to top of rad. Do you have it mounted vertically or horizontally?

the radiator is mounted vertically

[Guest]

1 hour ago, anphetamina said:

the radiator is mounted vertically

Then mount it so tubes are at the bottom and tilt it backwards so the top is leaning back to try and get the bubbles to the top. If it doesnt solve or get better within 1-3 days it probably isnt the cause

[anphetamina]

1 minute ago, Abyss Gaming said:

Then mount it so tubes are at the bottom and tilt it backwards so the top is leaning back to try and get the bubbles to the top. If it doesnt solve or get better within 1-3 days it probably isnt the cause

How do I need to place the radiator? I'm not getting what you're trying to tell me.

[Guest]

5 minutes ago, anphetamina said:

How do I need to place the radiator? I'm not getting what you're trying to tell me.

So the tubes stick out of the bottom.

 

THen tilt the PC back by putting a big book or something in the front below it

[anphetamina]

1 minute ago, Abyss Gaming said:

So the tubes stick out of the bottom.

 

THen tilt the PC back by putting a big book or something in the front below it

I can't mount the radiator like that, I have a NZXT s340 and the tubes are too short or hitting the GPU, the only place I can mount the 240mm radiator is on the front panel case.

Is it safe to unmount the radiator and run the system placing the radiator like that outside the case without any fans attached to it? For how many time do I need to run like that to see if the air bubbles move?