Here is a clip of the sound
https://youtu.be/9sSySF9Ygg8

 

Oh wow, that's terrible. Here that would be a warranty claim, but I think it's time for you to insist that your dealer works out exactly what's making that racket rather than change parts that may, or may not fix the problem.

With regards to the recirculate button, I have never left mine on long enough for it to happen, but I do believe the car will revert to outside air intake after some time (20 minutes rings a bell, but I'm not certain). This is to ensure the air inside the car doesn't become too depleated of oxygen and too dry.

The 2020 US HEV manual says (Page 3-149 and 3-152&3)

 

Hello.

I have the same problem.
Did they give you any solution? Did they find the cause?

Thank you.

 

We have the exact same issue with my wife's 2019 Ioniq Hybrid Blue. Our car is still under the original factory warranty and we left it with the dealership and they claimed they couldn't figure out what the issue was even though it happened while in their possession but only for 30 seconds so they weren't able to "diagnose" the issue and gave us back the car.

We hadn't tried turning off A/C recirculation but we are going to try that for the next few days and if we don't hear the noise, we're going to send it back to the dealership with this new info.

Anyone able to successfully get this issue fixed?

 

Do you have another dealership in the area? I had to get my car repaired at an out of city Hyundai myself.

 

The second dealer said the struts were worn. First dealer didn't find anything wrong. After struts replaced car was tight and responsive..but now after 7 months of trying to ignore it progressively getting worse I feel the same issues I was.

 

Hi, I have the same problem. did you find the cause for this sound?

 

I haven't. I have another appointment with the dealership to have them look at it again because it's getting more frequent and annoying.

 

I have a 2018 phev ioniq with the same sound. Mine lasts 5 to 20 seconds. Dealership wants 2 to 3 days to diagnose but no guarantee and last time, even with video of the sound, said they couldn't find anything.

 

Same thing at the dealership I went to. They just wanted to send the car back without even trying to diagnose the issue for more than a few hours (this was the second time I left the car with them regarding this issue, the first time they claimed they couldn't duplicate the issue). I ended up emailing the dealership president, sales manager and service manager. Then they finally decided to keep the car for a few days (they provided me with a loaner) and ended up replacing a fair amount of parts. I've attached screenshots of the work order/receipt I received from the dealership showing what they did (they kept the car for about a month waiting for parts to come in).