[Sam410]

I bought a 2016 SE in June.The day after I bought it, I noticed I had an intermittent noise coming from the rear of my car. You cant not notice it because it is LOUD. Its coming from the right hand side of the trunk, from the vent on the wall. There is no rhyme or reason to it.sometimes its multiple times a drive, sometimes it doesnt happen for days. Sometimes it lasts a full miute and sometimes its a blip. Its really odd.
Since it was still under warranty, the dealer tried to fix it. He couldnt hear it himself, so going by the video I had plus me finding a video online of the same noise where they fixed it by replacing the rear blower motor, they replaced the blower motor. The car made no noise for two weeks.
So I brought it back and they honestly have no idea what the issue is. They had me try shutting off the air when I hear the noise to see if its a bad part, but the noise doesnt stop when I do that.
Its driving me mad. Any ideas? I am out of warranty now but they will still cover fixing it if I can figure out what the hell needs fixing 🙄
I know next to nothing about cars so please do t recommend fixes for ME to try. I just need to know what to ask the mechanic to do.
Ive attached a link to the video I took of the noise here : Noise
Thanks!

 

[2011.2017.odyssey]

passenger side spring seats are common to blow out on these, but that would make a clunk over bumps.
very obvious over speed bumps..

there was a TSB for body clunks related to welds, but that was on the drivers side in the B pillar area.

Was a post within the past 6 months with your same complaint, I don't think there was a solution to that one either.

If you're certain its behind the panel, then remove the damn thing leave it off, and have someone drive while you ride in the back and try to isolate what it is.

 

[oldskewel]

EDIT - I wrote the bottom part before actually watching the video. Will leave it as is, and some of it is still relevant, but ...
Wow.
Was the key in? Engine on?
Could you - next time - get out and get closer to the source location and record as you move the camera around.
Could it be from a speaker back there? Sounds electrical. These cars have ANC - Adaptive Noise Cancellation - where they have microphones listening for road noise, and then have the speakers try to cancel that. This could be a malfunction of that system.

========== before watching the video ... ============
Does it ever happen when the car is turned off, key out?
.... key in, engine off?
.... engine off, AC turned on? (of course the compressor would not be spinning)
.... engine on, in Park?
.... driving down the road, all HVAC off?
....
.... see the pattern - even if you don't know how something could be fixed, you could do some simple testing to see when the problem might appear. Of course with an intermittent problem, a negative result is not conclusive.

So one way to work with this limitation is to wait for it to happen, and then very carefully see what will make it stop.
Let's say it happens when you're driving down the road with the rear AC on.
Drive to a stop, engine still on, AC still on. Noise still there?
... rear AC turned off, fan still on ...
... rear HVAC fully off ...
... engine off, key turned back to on ...

The previous post refers to a potential problem that would only happen when you're driving. But if the problem will happen when you are at a stop, that alone would rule out that theory.

 

[Sam410]

EDIT - I wrote the bottom part before actually watching the video. Will leave it as is, and some of it is still relevant, but ...
Wow.
Was the key in? Engine on?
Could you - next time - get out and get closer to the source location and record as you move the camera around.
Could it be from a speaker back there? Sounds electrical. These cars have ANC - Adaptive Noise Cancellation - where they have microphones listening for road noise, and then have the speakers try to cancel that. This could be a malfunction of that system.

========== before watching the video ... ============
Does it ever happen when the car is turned off, key out?
.... key in, engine off?
.... engine off, AC turned on? (of course the compressor would not be spinning)
.... engine on, in Park?
.... driving down the road, all HVAC off?
....
.... see the pattern - even if you don't know how something could be fixed, you could do some simple testing to see when the problem might appear. Of course with an intermittent problem, a negative result is not conclusive.

So one way to work with this limitation is to wait for it to happen, and then very carefully see what will make it stop.
Let's say it happens when you're driving down the road with the rear AC on.
Drive to a stop, engine still on, AC still on. Noise still there?
... rear AC turned off, fan still on ...
... rear HVAC fully off ...
... engine off, key turned back to on ...

The previous post refers to a potential problem that would only happen when you're driving. But if the problem will happen when you are at a stop, that alone would rule out that theory.

I dont use a key, its keyless entry, but it happens when the car is on. Driving and in park. Sometimes it happens as soon as I turn the car on,
Ive tried turning everything off, it doesnt do anything. Its really a mystery.
Its coming from behind this vent, really close to the surface.

 

[dvpatel]

Did they check the blend motor (not the blower motor)? If they did not, ask them to. This sounds either like the blend motor (just a lot louder than normal) or something getting in the way of the actual blower.

If its the latter, turning off the climate control should stop it. If its the former, only way to stop it is to push the rear temp all the way to coldest setting or the hottest setting. Also. The blend motor makes the noises regardless of if the climate control is ON or OFF.

 

[phattyduck]

One of the rear AC actuators. Normally happens to the front driver's side mix motor... but you are one of the lucky ones!

It will likely make the noise in 'reliable' manner if you change either the rear temperature (fully hot->cold or cold->hot) or vent location (face->foot or foot->face). That will tell you which one.

I think both are on the back side of the rear AC unit and require some work to change out.

-Charlie

 

[Sam410]

Did they check the blend motor (not the blower motor)? If they did not, ask them to. This sounds either like the blend motor (just a lot louder than normal) or something getting in the way of the actual blower.

If its the latter, turning off the climate control should stop it. If its the former, only way to stop it is to push the rear temp all the way to coldest setting or the hottest setting. Also. The blend motor makes the noises regardless of if the climate control is ON or OFF.

They said they checked :/
If it is the blend motor, will the noise eventually become an actual mechanical problem or is it just an annoyance?

 

[Sam410]

One of the rear AC actuators. Normally happens to the front driver's side mix motor... but you are one of the lucky ones!

It will likely make the noise in 'reliable' manner if you change either the rear temperature (fully hot->cold or cold->hot) or vent location (face->foot or foot->face). That will tell you which one.

I think both are on the back side of the rear AC unit and require some work to change out.

-Charlie

I'll try that, thanks.
If it was the acutuaor, wouldnt it cause the AC not to work? Everything works fine, its just noise

 

[phattyduck]

Everything works fine, its just noise

Are you sure everything works with the rear AC? Try adjusting to roof only or floor only vents and see if the airflow is correct... (or, maybe the actuator finally starts working after clicking for a while - not ideal, as that would be wearing out the internal components and it would keep getting worse)

-Charlie