I have a 2013 Impreza premium with a manual transmission. It has 90,000 miles on it. It makes a grinding noise when accelerating above 3k rpms ish while cruising and lightly touching the throttle. The transmission has a bad 5th gear but I’m not sure it would cause this to happen in all gears. I initially thought it was an exhaust rattle but it doesn’t sound like it, it sounds like grinding. It could be the differential but It coming from the front. Any thoughts? I have linked a video below.