I saw an earlier post about a metallic or scraping noise the manual 4 liter makes when downshifting while on auto-blip, or even when giving the motor a quick rev from idle. But the discussion went immediately to a debate on Auto Blip vs Heel-toe. Has anyone else experienced this sound? I just started using auto-blip after 1500 miles, and the noise was immediately obvious. The sound is immediate upon throttle, and precedes the engive actually revving. Way more noticeable when the windows are down. The timing of the sound reminds me of the noise a carburetor makes when you rev a motor, first the sucking then the revving - but this noise is like a grinding sound.

 

I believe it is just the sound of a quick squirt of fuel from the injectors. My C7 Corvette with auto-blip did the same thing and that was the case with that car. Normal.

EDIT And yes, to confirm, my CGTS40 does it as well.