I went to a different mechanic, and they don't think its a drive train issue. Instead, they think that there might be a carbon buildup which is causing detonation. I'm going to see if Seafoam helps

Another bizarre discovery I just made is that is does not rattle when in neutral and NOT moving (~2500rpm), but it will rattle when in neutral and the car IS moving (~2500rpm). No clue what this could mean though.

Another long shot, but I had a relative's matrix suffer a failed upper motor mount, so bad that when the engine was under enough torque (accelerating), it would shift and open an exhaust joint. Found it by gunning the engine in gear with the brake pressed hard (not moving) and hood open, kinda scar...

Oh also another thing: It seems to disappear immediately as soon as I let off the gas

Hard to say without hearing it Sorry for such a late response, but I finally recorded a short video: https://www.youtube.com/watch?v=gYcPPe8EBhE Its pretty difficult to hear in the video, I think its most prevalent around the 19 second mark. I also had someone from a shop take a quick look at it an...

Hi all! I am new here, just bought a well-worn 2007 1.8L Vibe, and for the most part it seems to be working well. The main issue I am facing right now is that there is a annoying noise coming from the front when I accelerate. It seems most prevalent in 1st gear, but it does seem to be audible in 2nd...