AIO cooler noise?

[HelloPeople]

I have a Silver Stone TD03-Lite AIO Cooler (120mm Rad). Most of the time it is quiet as I liked it to be, but the problem is sometimes there is a high pitch noise that came from the pump. is this normal? because i've used Cooler Master Seidon 120m AIO cooler before and there is also this similar noise. if this is normal for these cooler, is there any 120mm AIO cooler that does not make these high pitch noise?

[ind3x]

Lots of pumps run at full speed at all times to ensure optimal performance, but this usually creates a  small whine.

My h80i has the same problem, and there's nothing to do about it.

[Drixen]

Sounds pointless because this usually goes for custom loop, but try tipping the PC side to side and up and down to see if there's an air bubble in there. Even though it's AIO my previous H100i GTX did this and it worked. Even take your radiator (very gently and just tilt as well.. no shaking)

[HelloPeople]

Sounds pointless because this usually goes for custom loop, but try tipping the PC side to side and up and down to see if there's an air bubble in there. Even though it's AIO my previous H100i GTX did this and it worked. Even take your radiator (very gently and just tilt as well.. no shaking)

 Sorry for the late reply, and thank you very much, I'll try this when i get the chance.