The high pitched buzzing sound is likely your fuel pump. Normal. Might need a fuel filter change if it's struggling to push fuel. That can make them louder than normal.

Not sure about the tapping. Could be a number of things. Best to get a vid and post it here so we can hear it.

If you haven't already, start your own thread in the 3.8 S/C section for more help. We don't want to clutter up this thread with unrelated tech.