2021 CX-9 turbo noise when hot outside

[Gremlin]

I've got a 2021 CX-9 GT, I was out road-tripping/camping with the family the last couple weeks and noticed when we were in outdoor temperatures of 100F+ there seemed to be noticeably more whine from the turbo when the car was accelerating in 1/2/3 gears, not an excessive amount of additional noise, but definitely an 'I haven't heard it make that sound before' amount... Once we got up about 30-40mph it was no longer noticeable due to regular road and wind noise. The car performed normally otherwise, no errors or issues, I checked the oil level and it was good/normal (just below the max line where I'd topped it off to after getting a low level warning about 6 months ago), coolant level was good also. When we were up in the mountains and the temps were in the 80's, no additional noise and it sounded like it usually does when driving around town unloaded, but whenever we were lower and the temps got up to 100+, it would return.

I'm probably just being paranoid, it's probably normal/fine, going in for its first oil change next month and I'll ask the techs about it then also, but figured I'd check here just in case.

 

[roundle1979]

Are you certain it was a turbo noise and not the cooling fans you heard kicking on and off?

 

[Gremlin]

Pretty sure it wasn’t the radiator fans, it was a higher whine and shifted pitch with engine RPMs. Now that we’re back home and driving around with the windows open, it’s still making the whine, but much, much quieter. Sounds like it’s probably a normal engine noise that I just haven’t noticed before because we typically drive with the windows closed. It was just much louder when the outside temperature was 100°+.

Through it all the car hasn’t had any issues at all, so, I probably just need to better learn the car’s normal sounds, we’ve had it less than a year. My wife always makes fun of me because I can hear little creaks/whines/car noise changes that she doesn’t… even though most of the time I’m right and it’s saved us from what would have otherwise been some expensive headaches a few times.

 

[roundle1979]

I can definitely hear some turbo spool/whine at some lower speeds (when tire / wind noise does not drown it out) while under moderate acceleration. Likewise, if I get on and off the gas aggressively I can hear the turbo's blow off valve whooshing which is kind of cool.

 

[sm1ke]

On my 2018, under moderate to heavy acceleration there is an audible beeping/whistle sound that comes from the engine bay. I have learned that this is just due to the way the air flows through the components under load. There is also a possibility that there is a loose clamp somewhere on the air intake inlet that could also be a culprit. There were a few people who installed the JB4 intake, which replaces the OEM turbo inlet pipe close to the firewall in addition to the intake box that houses the filter. Some of those people reported that when they went to install the JB4 turbo inlet pipe, the OEM clamp was loose.