Once in a while (but it seems like the frequency is increasing) I hear a noise while I'm driving. At first I thought there was a small animal stuck in the car but after a couple of weeks I decided it was something else. It sounds like "woop" with it getting higher pitched towards the end of the sound. It's hard to tell where the sound comes from. For many weeks I thought it was coming from inside the driver side dash. I also thought it had something to do with slightly turning the wheel to the right because it seemed like that's when it happened. Then I realized it happens when I drive straight too. Then one day the engine was running and I was in the back with the tailgate open and I heard it again but it sounded like it was right near me. That's when I realized it wasn't coming from the dash or the steering. My wife says it sounds like it is on her side when we are driving. The only way I can imagine it sounds like it is coming from wherever you are is if it is coming from the speakers. I asked the Ford dealer about it and they thought I was crazy. I made them go on 3 test drives with me and of course it didn't do it when the technician was around.

Has anyone experienced this or know what it is? I can't find any info on the internet about it. Thanks.

I have a 2005 Explorer Limited and I know the exact noise your talking about. I seam to think it has to do with the a/c. When I have the a/c on in the front only it makes the noise, if I turn on the back a/c I don't here the noise. Or thats what I have figured out so far. The dealer told me there is an a/c unit for the rear by the back wheel well. I'm going to check into this further and let you know what I find out.