Siren-Like "Whoop" Sound on 09

[AuburnTiger]

Lately I have been getting an occasional loud "whoop" from my 09 EB that sounds like a police siren yelp. It sounds just like a police car right beside or behind me hitting the siren for a quick pop. I can't replicate the problem, and I have no idea what's causing it. I was reading in the 5G Explorer forum that this seems to be an issue for them, but I haven't seen any other 4G vehicles having this issue. The guys on other forum think its related to rear a/c. Anybody here ever run into this weird sound problem?

 

[07EddyB]

Yes - I have. It's been a few years but it only happened with the air on. I don't really run my air that much so I never really looked into it but it seems to have worked itself out at some point since I haven't heard it again in a few years. Again, though, I really don't use my air that often.