For a while now, my 2000 TL-P has made a "whooshing" sound every once in a while. I was finally able to narrow it down and was wondering if anyone had any idea what it could be.

It only occurs when the car is moving, never when in park.

It only happens when I'm giving it a little throttle. Under hard acceleration, it makes no noise.

I can reproduce the sound pretty much at will now by bringing the car up to 35 MPH or so, then giving the car just a little throttle and bring it up to about 40 MPH. If I hold the throttle there, it keeps making the sound up to about 45 MPH. Because of this, I notice it most when driving in traffic.

Has anyone had this happen?

I thought it might be one of my fans going bad, so I disconnected it. Nope, still makes the sound.

Other than a little slippage between gears 2 and 3, the car runs just great, so I haven't been too worried about it. The only other clue is that my A/C motor has been making rattling noises (maybe some pressure-valve getting noisy?)

I can't think of anything special that happens at 40 MPH, but who knows?

(BTW: I don't have my AEM intake anymore.. I'm back to stock so it's not that. It made the noise with that intake and without)