I have lived in an appartment for a few years now, but a few weeks ago I started hearing a strange squeaky noise late at night, particularly loud in my bathroom. It pulses, and I thought it might be electronic at first, but the more I've heard it the more metallic it sounds. It now happens nearly every night, usually starting around midnight and going on for hours. Sometimes it'll stop for a few minutes before picking up again, but it more or less continues all night.

It sounds like someone twisting a squeaky faucet back and forth, on and off, repeatedly. I'm not doing anything-no faucets on, toilets flushing, or shower running, which seem to be the causes of squealing pipes according to Google. I wondered if my neighbors were doing something to cause it, but when I asked they didn't know anything, and they say they don't hear it either.

I made a recording of the sound and brought it to my apartment's office to get maintenance to help, and they had no idea what it could be. Since it only happens at night, they can't come listen to it as it's happening.

Today they tried turning on the irrigation system during the day to see if it might be related (since it's on a timer and starts at midnight too), but of course the sound didn't happen.

So here I am, with an annoying mystery sound and several questions. What could cause a sound like this? Something that isn't a continuous squeal or a short burst, but a regular, periodic noise that starts and stops and goes on for hours? Why is it only happening at night? What can I do about it?

Thanks in advance for any advice!
I can upload a recording of the sound if it would help.

Yes, let's take a listen. I'd bet it's related to the irrigation system.



Edited 1 times.

Ask maintenance when the irrigation is programmed to start. If it comes on ~ 12:00- bingo.

I'm guessing water pressure is the greatest at night time as there is little usage compared to the day time. I'm guessing the irrigation system as well. Ear plugs, just may resolve the issue for now.

Best Wishes