jo Wander

Hi folks, We got a 93 imprezza hatchback here. Automatic trans. 1.8L . For the most part its great, but when we are driving on the highway, sometimes it starts to make a noise that resembles an old police car siren (goes from high to low pitch slowly). We thought it was the tape player first, but after turning that off, the noise continued. I also noticed that if we stop the car for a few minutes, that the noise would stop.... at least for a while. The power steering makes no noise at all while turning it all the way if that helps. Fluids are all good, I think. Any ideas what it could be? Thx,