ThunderCloudMetallic

Bullet points:
-Horrible siren noise
-Speed dependant
-Happens in any gear/neutral (manual)
-Occurs with two different sets of tires
-With and without window visors


I purchased my 2005 xB from the original owner about two and a half months ago. Every service of the 133k mile life is documented on car fax with the exception of one oil change as far as I can tell (you can view service records for free on mycarfax.com). It seems to be an excellent little car with one glaring issue. There is a horrible whirling noise like a tornado siren from 35ish to 55ish and up around 75-80. It is definitely speed dependant but not gear dependant (manual transmission). I've read that the Hankook optimo H727 tires that came on the car can be noisy but it makes the same noise with the used set of Bridgestone Ecopia EP422 that came on the Konig rims I bought for it. Both sets of tires have a surprising amount of tread left. It handles really well and doesn't pull one way or another so I don't suspect suspension or alignment issues though the Hankooks do have a bit of "saw tooth" wear pattern. I dont think it's a wheel bearing, don't those make noise no matter what, once they go? Any one have any other ideas what I should check into? Or are these cars just naturally noisy due to the brick like aerodynamics? Any thoughts or ideas would be appreciated as the noise is driving me crazy!

2stroked

I'd check the wheel bearings and the front half shafts first.

ThunderCloudMetallic

I've checked all 4 bearings the best I can and none of them had any obvious play in them. The noise is much higher pitch than any wheel bearing issue I've ever heard. And I've never had the bearing growl go away at any speed like this noise does. In my experience bad bearings always just get progressively louder the faster you go. My noise seems to be effected by the wind. Head and tail winds seem to change the speed at which the noise starts and stops and cross winds kill the noise completely. Turning, heat/AC/fans, gear, clutch in/out, neutral coasting all have no effect. I took some videos and posted them on YouTube so you can hear it.

ajayaitch

Windshield seal. Mine's done it in the past when the installer doesn't get it quite right. Though in my case, a cross wind would make it whistle like a kazoo.
Use some painters tape to seal it up temporarily and take it for a test drive.

ThunderCloudMetallic

I've been testing and checking lots of things and I dont think it's anything mechanical. Someone even suggested changing the transmission fluid. I will because it needs done anyway but I think you might be onto something there with the windshield gasket. I'm also suspecting the aftermarket grill that came on the car. I was given the original as well and noticed the original is actually a solid piece, it wouldn't let air through. The aftermarket is more like a typical grill, it has slots and let's air through.

ajayaitch

There's the gasket/seal, but it's also glued in. I've had, IDK, 7 windshields put in my car maybe? After the 2nd time, the original seal was too brittle to reliably be reused and the 'OE' replacement looked like crap. So they put a different style in, one that covers a little bit of the windshield and a little bit of the frame. Kind of a T shape, if you can imagine it.
My car's not here right now, so can't take a pic to show what I mean. It helped, but being properly glued in helps more, and is vital to keep water out of places it shouldn't be, as well as wind.

ThunderCloudMetallic

Aftermarket grill, replaced with OEM
Noise reduced significantly with masking tape (aftermarket grill)
I put tape over the aftermarket grill and the top of the windshield, it was an amazing difference! So I reinstalled the OEM grill and removed the tape from the top of the windshield, it's still quiet! Any ideas what I can put on the top of the windshield to close up my gap? Any ideas how I could quiet down the grill? I like the way it looks but if I can't quiet it down I'll have to find a new home for it Gap at top of windshield

ajayaitch

Here's what my windshield seal looks like...
For the grill, perhaps make a solid panel that fits behind it to block the wind.

ThunderCloudMetallic

Maybe I'll get a small rock chip that forms a crack and spreads across the entire windshield within 3 day like so many others. If I do I'll make sure they use a better gasket when they replace it.