Yesterday upon pulling on the freeway a loud and annoying buzzing or whistling type noise started happening. It sounds like it’s coming from right behind the middle of the dash. It’s been very cold here in Minneapolis, nights -15+. It’s garage kept, but not heated.

Further diagnoses, no noise at idle or slow speeds, heat works fine, it only happens above 35-40mph, and goes away completely if I turn on recirculate. I’ve already pulled out the air cabin filter behind the glove box, nothing seems odd there.

Based on all that, I definitely think it has something to do with the cabin air intake, but I’m not sure where else to look for some sort of blockage or debris.

Any thoughts on where to check next?

It’s a new to me 21 disco with about 58k miles, put on about 2000 miles since taking ownership a couple months ago.

thanks

 

any thoughts?

 

In case anyone else comes across this, it turned out to be a leaking windshield. Wind at just the right angle would cause the noise.