Hello, just wondering if anyone else has come across this noise. My 2018 CX-5 has started making this siren/whoop noise that can be heard when the car is idling. It almost sounds like a warning signal. My wife an I actually thought it was a police car nearby several times when we heard it. It's not real loud, just subtle enough to hear inside. Sounds like it's coming from the front dash area, but not totally sure, as it only does it maybe once or twice every 5 minutes. My only guess right now is that it might have to do with the A/C system, as the A/c is running and the fan is on low. I have checked online, and the only other things I have read about is a siren noise on GPS units that aren't activated, but that doesn't make sense since we've had the car over a year. I read another article that said several years ago some Ford Explorers were having a similar issue, and it turned out to be the A/C & heater ducting leaking air.

Anyone else heard this or know about it? Thanks in advance.

 

So after some research online I found out what this is, just want to post in case anyone else is looking for an explanation. It's not just related to Mazdas, but many different car makes. It can be one or two things, or a combination of both. Moisture makes its way into the A/C system and begins to freeze on the expansion valve, causing the whoop noise when the A/C compressor kicks in. The first step is to evac the system, put the system on a vacuum for at least an hour to get rid of the moisture, and then recharge the system. Sometimes this works, if not, then the expansion valve will need to be replaced. Mazda is going to evac the system first and see if that takes care of it.