2017~2020 2018 CX-5 siren/whoop noise

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.
 
:
2019 CX-5 Signature
If possible, could you provide a recording of the noise?

Turning off the AC and the noise goes away?

You can turn off the AC and just run the fan. Change the air direction and see if the noise changes.
 
Haven't been able to record yet, but I will.
The noise doesn't seem to happen when A/C is off, or if I increase the fan speed, which makes me think it's either the fan motor or something to do with the ducting, as you can only hear it inside the car, not outside. Maybe when the A/C kicks on or off it causes some sort of resonance in the ducting.
I'm going to try reversing the air flow from outside air to inside air and see what happens.
 
:
2019 Mazda CX-5 Skycruise 2.2D AWD
I think I had the same the past days and I believe it is related to heavy side winds. It has been very windy out here. It only happens on the highway at higher speeds. It sounds like wind is entering the car through the edges of the front windows or open roof (when closed of course).
 
:
13' CX-5 and 16' Mazda6 both Touring w/Tech/Bose
Finally got an electronic siren sound. Faint. Goes away when I brake.
 
:
2019 Mazda CX-5 Skycruise 2.2D AWD
I think the noise is more inside the car. I had side mirror noise in my Nissan Qashqai/Rogue an d that sounded different.
 
:
13' CX-5 and 16' Mazda6 both Touring w/Tech/Bose
It sounded like electronic noise/interference. I was entering a construction zoe with lots of trucks/police calls, radar speed checker, ect.
 
The noise occurs when idling in park, so no wind noise. If you can imagine a police car turning on his siren for just a second, that is what it sounds like. Sounds electronic. Kind of a short low "whoooop! sound, almost like a siren starting to go off. Lasts maybe 1 second.
Car is parked, idling, with A/C on, fan at #2 level, blowing out top and bottom vents. Can't hear it outside the car, just inside. CX-5 is a year old, just started last week, no changes to vehicle.
Still thinking A/C or ducting, but just a guess. Nothing else is moving in the interior while idling that I can think of.

Thanks for the replies. It has me scratching my head!
 
Yes, that is what it sounds like! How did you find out it was condensation? That's a strange sound for condensation to be making. Is there anything you can do about it? Mine doesn't normally do it when moving just when I've been idling for a while. But it was very hot and humid outside.
 
Thank you for the reply. It seems to make sense. My car has not made the noise in a week now, which I'm glad about, but then again we haven't been sitting in the car and having it idle for a while, so maybe it has something to do with that. I took it to Mazda when I got my rocker arm recall fixed today, and of course they couldn't replicate it, so they told me to bring it back if it becomes an issue again, but they did note it in my file.

Thanks again.
 
So this noise started up again, and although it did sound like the condensation drainage sound clip, I researched other car makes and found out what it is:

It's not just related to Mazda, but many different car makes. It can be one of two things, or a combination of both. Evidently a little bit of 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 for me. I had a sound clip of it, and after listening to it they agreed with the assessment. The service manager said he had seen it in the past on Acuras.


Just wanted to post this info in case it will help someone in the future.
 
:
2017 CX-5
Thank you, OP. I have exactly the same issue in my 2017. Was able to record it and played it for dealer, who also thought A/C system. I haven't done anything about it, but will suggest this fix when I next talk to them.
 
Noise is back, evac did not work. Will now discuss with Mazda about replacing the expansion valve, as by reading on a lot of forums this seems to be the only way of getting rid of this noise.
 
:
2017 CX-5
Noise is back, evac did not work. Will now discuss with Mazda about replacing the expansion valve, as by reading on a lot of forums this seems to be the only way of getting rid of this noise.
Geno (or anyone else with this issue): Any luck with replacing the expansion valve?

Thanks
 
Yes, replacing valve solved the problem. Mazda finally came around and paid for it even though the mechanics never heard the noise.
 
Top