I can't seem to find a good photo of m57d30tu2 engine.
But, you can trace the turbo yourself and learn along the way. On passenger side of the engine, trace exhaust manifold and the manifold's exist. The manifold exits into a turbo. You may have to remove some shields to see the turbo, but not sure you need to yet. Since the alternator is on the driver's side bottom and AC is on bottom side passenger side, if the sound is top passenger side, then yes, a turbo. Just doesn't sound like it is the turbo.