Bubble sounds?

I drive a 2003 Honda Odyssey. After some debate and close attention I am certain I hear a sound like a bubble popping. It seems to be mostly towards the left side of the steering wheel/dash. Part of my debate is that it is inconsistent and I often wait a few days to hear it again- speeds, distance traveled, amount of braking, etc. I can’t pinpoint. What is this sound that is making me crazy?

Does it sound like it’s coming from inside the dash? And does it matter whether your heater is set on hot or cold? I’m thinking it might be the “blend door” flopping open/closed. The blend door is a plastic door inside the dash that controls the mixing of hot and cold air for your heater. On some cars the blend door is actuated by a vacuum line from the engine, and sometimes those go haywire.

Not sure about dash, sort of yes. I’ll have to pay attention to the heat settings, but this did start in November when the temps were cool and started adjusting warmer for comfort. Have noted the rear of the van doesn’t seem to have high heat output and had wondered if there was a problem with the fan/blower for the back controls… might be part of this?

Can You Associate The Inconsistent Noise With Braking, Turning, Or Going Over Bumps ?

On certain (not all were involved) 2003 Odysseys a “dashboard” (or front fender area) sound can come from a front strut mounting base. Honda’s got a Technical Service Bulletin on it.

CSA

Honda Chose To Revise Front Stabilizer Links On 99 - 04 Odysses To Take Care Of Clunks, But I’d Think That Would Be More Regular Over Bumps.

CSA

Yes, if the blend door is stuck in the wrong position or flopping around, you won’t get as much heat.