Hey Hondatech. I've got a bone stock 2011 Civic Si with 71k miles. I just noticed tonight that it has started making this odd clacking noise that starts right at 3000 rpm. I did a 1-3 pull, and noticed it almost immediately after. Some things that may be notable: I have a slight misfire at idle, needs new spark plugs. Waiting for them to be ordered in. I also just recently adjusted my clutch master cylinder. Not sure if any of those would have anything to do with it. I noticed the noise is more audible when the engine is under load. Revving in neutral, you can't hear it. Any helpful input is appreciated.

 

Video of hitting gas and brake at same time in 1st gear to simulate load.

 

Video of warm idle