DIAGNOSIS That's the refrigerant circulating through the cooling system. It's completely normal, especially during the initial 24-hour break-in period or after a defrost cycle.
FIX Let it run. The noise should lessen significantly after the first day as the system stabilizes.
IF THAT DIDN'T WORK If the loud gurgling persists for days or turns into a grinding or rattling sound, the unit might not be level. Use a small level on top and adjust the front feet until it's perfectly flat. An unlevel unit can cause compressor strain and noisy refrigerant flow.
HEADS UP Don't panic over operational noises like humming, clicking (thermostat cycling), or occasional light bubbling. A consistent loud buzz or violent rattle is the problem noise to watch for.