Liquid CPU Cooler loud makes weird rattling noise. Noise lessens when leaning to the left.

lamb_22

So I built a brand new PC, everything was great. After 3rd start or so this loud rattling noise started from CPU area. Weirdly, when you tilt the PC to the left (tempered glass side down) the rattling eases and almost subsides.... flip it upright and it the rattle starts right back. From other posts,  I have checked all the case screws, case fans, PSU screws, the cpu cooler fans, and the cpu cooler io itself and determined the nosie is clearly coming from the heat sink region of my CPU cooler where it contacts the CPU and motherboard (I have checked all the mounting screws they are not loose). From what ive seen, re setting the cpu and cpu cooler cooler positioning doesn't seem to ease the issue.. is that always the case? Should I disassemble the PC again and start again? Do I need to return this CPU cooler?  (Parts: Mob - MSI x570, chip Ryzen5 3600, cooler Cooler Master ML240l. Compatibility is not the issue, but figured I add the specs in question.) PLEASE help guys/girls, I have a video but it wont allow me to attach. 

TSTonyV

Most likely there's a little bit of air stuck in the pump that is having trouble working itself out.  Unmount the radiator, tip the chassis on its side, then take the radiator and tilt it 90 degrees to get the fluid that is inside of the radiator into the pump. Try that for a while and see if it helps. 

lamb_22

@TSTonyV
I will try this in a few hours after work. Will circle back, thanks for the input fingers crossed. 

PowerSpec_MichaelB

Sounds like a plan. I would also recommend taking a look at this video: https://www.youtube.com/watch?v=JT_u_eLVoIc. While your CoolerMaster AIO isn't manufactured by Asetek, the same principles apply as it's common across all AIOs due to the nature of their design. Another thing to note, when he says "hex" in the video, he is referring to the radiator. If you have your fans pre-attached to the radiator, be very mindful of where your fingers are when you handle the radiator with the pump running, as the fans will be spinning too. It may be best to temporarily remove the fans, get the pump running, shake the radiator back and forth (or rotate 90 degrees until noise is gone) then mount the unplugged fans to the radiator, mount the radiator to your chassis, power the system down, plug the fans back in and try again.

Once you get the hang of the quirkiness of these AIO's, it'll be a lot easier in the future should you choose to go this route for cooling.