cold weather...

the cooling fan on the stereos/entertainment unit on these things squeals on cold mornings, once you unlock the door.
Mine has been doing it for years could be that.
same issue on the pilot.

2012 Touring w Nav - Stereo groaning / squeeling when...

So I finally solve my vibration issue and now this is happening constantly in the morning. The past 3 days... This had happened intermittently in the past, and seems more prominent the colder it gets. Functionality of the unit is unaffected. It sounds like the motors in the dvd or cd player...

www.odyclub.com

take a video of the noise, and general location its coming from, it helps a lot.

how long have you owned the vehicle? cold weather and poorly performing O2 sensor/heater will take a hit on the gas mileage.

 

Initial guess based on limited info - it's a moving part of some sort, possibly a fan or something with a bearing as @2011.2017.odyssey mentioned. Possibly an HVAC door motor/actuator.

See if you can narrow it down. Does it go away if you don't use HVAC at all? Does it go away if you stop using other systems?

 

I am not sure if it is the stereos/entertainment unit causing the noise. I can't hear the noise when the engine is cold but as it gets to the operating temperature it starts to happen. It seems like it is coming from around the passenger side door, but everyone who heard the noise seems to have a different opinion, right side sliding door, floor, and, etc.

I got this vehicle not so long ago, July 2021. I have already installed the S-VCM module and planning to do the timing belt job, valve adjustment, pcv valve, and spark plugs...

I was thinking that it might be the Winter gas causing the poor fuel efficiency but it seems a bit too much.

 

Is it possible that the sound is less of a high-pitched metal-on-metal sound, and possibly something more like wind noise getting through somewhere, possibly speed based and/or wind direction/speed based? Like wind sneaking through somewhere and acting like a flute and playing a high-pitched note under just the right conditions.

It would account for the semi-randomness, the connection to 40Km/H, and the shifting source locations.

Passenger side seems to be the culprit. Possibly door seals, glass seals, the opening under the windshield wiper tray where the HVAC gets outside air as input, and so on....

Just a thought.

 

maybe its just a rattling heat shield on the back catalytic converter?