I just got an oil change on ny '02 WRX wagon and now when I accelerate I hear a hissing kind of noise from the front of the car when I accelerate. It's tough to describe sounds, but the best I can say is it sounds like a metal contaner being filled quickly with air or water. It goes away as soon as I take my foot off the gas. Any ideas? I don't know if the oil change is just coincidental, but it's suspicious.