A couple thoughts:


1) vs. a little throttle, does putting in neutral stop the sound

2) it's reminding me of Jake brake just intemittent and softer and higher frequency than a semi.

Does your engine have exhaust braking? I could not find reference yes/no online.

3) intelligent alternator control; the alternator is supposed to charge "only when braking/coasting"; if the alternator is kicking on/off a surge of force related to this could be causing motion that is causing right a physical tap or a surge of current can cause wires to slap.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)