If the liquid cooler is making odd sounds, you might have air trapped in the pump. This is quite common, as every AIO has about 5% of air in it. This space is a side effect of the filling process, and serves as buffer room for when the liquid heats up and cools off. Small air bubbles usually circulate through the loop and spend most of their time in the radiator; noises will begin to develop when those air bubbles accumulate in the pump (and you might see dips in performance).
Please try the following air purge a few times to see if you can dislodge that air pocket.
• Please remove your cooler.
• As a precaution, you should examine the whole cooling system for anything that doesn't look right.
• Before reinstalling it, reattach the pump back to your CPU.
• Plug the CPU water block into a fan slot on the motherboard and turn on the PC. This will power the pump.
• Place the radiator on a flat surface like a table and hang the tubes straight down off the edge. You will hear gurgling sounds while the air rushes into the radiator.
• This should resolve the issue, and the radiator can be mounted back into the case.