Mike: so I dropped it to neutral like you told me, on a long stretch road, at about 50mph, after I brought it to almost 25000rpm.
It started dropping gears immediately, like you said it will, and (I think, I am very mechanically challenged) right before it dropped from third to second I got this noise come on again, very briefly, but it was definitely there. When it got below 1800rpm it was smooth, and not interrupted. I brought it to a full stop before shifting back to drive...
I do not know if it means anything and I do not want to experiment with it anymore, since "engine behavioral" is absolutely not known to me. I'd rather have someone else to check it for me. Any volunteers? LOL