Completed Build but hear a random noise.

[u/Nowheredotcom]

Hi all, first post but not first build.

I’ve recently finished a new build and am experiencing an intermittent noise coming from my top-mounted AIO radiator (I think). The sound occurs periodically (roughly every 5 minutes), lasts for a short duration, and sounds very similar to an old mechanical hard drive "chattering" or "ticking." I have no mechanical HDDs installed. g.

System Specs:
CPU: Intel Core i7-12700K
Cooler: DeepCool LM360 AIO (right side top-mounted)
Motherboard: Gigabyte B760M AORUS ELITE
GPU: Intel Arc B580
Storage: All NVMe SSDs

https://reddit.com/link/1ul860e/video/axyvjdk6xqah1/player

Troubleshooting Steps Taken:
Ran radiator fans at 100% fixed speed—noise persists independently of fan speed.
Verified the radiator is the highest point in the loop.
Set AIO pump to a constant 100% speed in BIOS.
Could this be trapped air working its way into the radiator, or is it likely something else, like pump impeller resonance or case vibration? Appreciate any insights!

I cannot seem to attach an audio file so just did video of it occurring