Since a few weeks ago, I started hearing a scraping noise coming from the engine, I uploaded a video in which it can be heard ( ).
The sound only appears when the engine is warm (after ~10min. of driving) and around 1500, 2200 and 3000 rpm, in between or over those numbers I don't hear anything.

The sound appeared shortly after I changed the oil, I used 10w40 and a K&N oil filter. I also installed a new exhaust header, which you'll hear in the video, but the scraping noise was
already there before I installed it.

In the next few days I'll try to locate exactly where the sound is coming from, but just in case I wanted to post the issue here in case someone had a similar problem and knows what it might be.

 

Sounds like an exhaust rattle.