Get yourself a good pair of ear plugs and be done with it. I did have a rattle I thought was a heat shield and sure enough when I knuckled the D&D's heat shield it had an unsweet vibe. I bend it a tad until the knuckle rap test yielded silence.
I do hear lots of whirling, rat-a-tat-a-tat-a's, and ratcheting sounds, but all seems normal for my Rocket. After all, when metal touches metal a sound is made, whether we like it or not.
My Honda's sure let me know when THEIR running.