Like the title says, I can hear a leak under the center of my dash. The car runs fine and everything works like it should, but I can hear it and it drives me nuts! It comes and goes depending if I'm on or off the throttle, which is why it makes me think vacuum. Anyone else have this? Is it typical for the X3? There's a lot of stuff under there that would need to be removed so I can inspect, so I wanted to get some input before I tear into it. Thanks.

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2007 BMW X3 3.0si
2006 Ducati ST3s