My brother was reving the car and I turned it off when it was at about 5k+ rpm and it made a weird noise, I drove it after words but no difference, Did something happen By any chance?

 

you're good to go, don't worry
about it

 

Don't rev it

 

part of the beauty of modern engine managment systems is that you no longer need to do the "ricer rev" to clear out the engine. thats a drag racing thing that people with CARBURATORS do to clear a rich condition caused by the burn-out before launching from the tree.

bottom line -- you dont need to do that when you shut it off. and plus, it looks stupid to people who actuall know what that is used for when you do it.