Did a search and found this post from a few years ago, but the noise and the problem seem to be a bit different (lucky bastard only had the issue when the wind blew).
The AC in my apartment (electric, the kind mounted on the wall, not in the window, probably fairly new) makes this awful glug glug glug noise. It's constant and only stops when I open a door or window.
It's at its loudest and fastest pace when I have any vent on in the house (bathroom, 24 hour automatic vent system in the shower, vent over the the stove), or when the air conditioner has been on for more than an hour on a good day or 2 minutes on a shitty one. Even when the air conditioner itself hasn't been used in days, it still makes the damn noise, and even when all the vents are shut off I can still hear it – quieter and slower than usual, but loud enough to be impossible to ignore.
I've had this issue in other apartments, but usually, turning all the vents off while I'm out during the day would fix the problem for a few days. In this apartment, I have to have the windows open constantly, as it won't stop for weeks regardless of how long I leave the vents off or how little I use the AC.
It only happens (so far) when I've used the AC in the near-ish past; I hadn't touched it since sometime last year (I'd rather be cold with the windows closed in winter than cold with them open and listening to that noise all night) until about three days ago when I used it for all of about 20 minutes. Turned it off and 15 minutes later, that damn noise started up and hasn't stopped since.
Pardon all the profanity, but it's really driving me nuts (as is the heat seeping in from the window I have to have cracked).
How the fuck do I make it stop?
If possible, I'd like to find a solution for it soon; it's already 88F/31C here, and with how hot this apartment gets every summer, I highly doubt I'll be able to make it to October with just a fan and the windows open.
TLDR: AC makes god awful glugging noise when the windows are closed no matter what I do, how the hell do I make it stop?