Last night I was in the garage after riding home. The bike was still warm when it intermittently made a pitchy bleed-off noise. It sounded like air being let out of a balloon. It was coming from around the instrument panel area. My thought when I first heard it was that it could have been the fan but I'm sure it wasn't when I heard it the second and third time. I'm wondering if it's coming from the coolant tank? Anybody else ever hear this?