I have a 2000 Buick LeSabre Limited with 133,000 miles. A noise like an owl hoot comes from inside the dashboard when going over bumps in the road when the climate blower is on. It'* a relatively quiet hoot sound. It is sometimes heard faintly when the blower is off but is much more noticeable when the blower is on, no matter what the blower speed. Anyone know what could be causing such a noise (besides an owl)?

I've driven three 2004 LeSabre and haven't heard such a noise from them.

That kind of thing probably isn't model year dependent.

I wonder if it sounds different in varying circumstances like:

- High blower through defrost only
- High blower through dash vents only
- High blower through heater vents
- High blower through dash vents on recirc.

Audio file of hoot noise attached. On the recording it sounds more like a bell sound than an owl hoot.

The noise is consistent regardless of the blower being on vent, recirculate, etc. It'* sometimes heard faintly with the blower off but is much more noticeable with the blower on, even when on low. Perhaps the blower is being jostled when going over bumps and making noise where it mounts to the car.

Weird. If I hadn't read this thread I'd think that is a loose exhaust pipe.

sure sounds like something is loose. check and make sure the blower motor is secure. the squirrel cage could also be loose on the blower motor.
Owls and Squirrels, that'* a good one. LOL.
seriously though, check it out and let us know what you find.

You are correct. The squirrel is causing the owl to hoot.

The blower motor has about 2 to 3 mm of axial play. Going over bumps causes the squirrel cage fan to be jolted up and down. The motor axle and fan together have a resonant frequency that gives an owl hoot sound.

Attached is an audio file of the hoot sound of the motor-fan assembly that I removed from the car. While holding it with one hand, the bottom of it is being impacted with the other hand to simulate going over bumps in the road.

I ordered a new motor-fan assembly but haven't installed it yet.

Good find!