So I jus bought an 02 Impreza RS (auto) about 3 days ago. One thing I noticed is that when I put the engine under a heavy load, I hear a blow-off valve/turbo like whistle/chirp come from what sounds like the engine bay. I noticed it happens when I get around 3-4000 rpm. If anybody has any ideas on what it could be or any advice Id deeply appreciate it.