[Erik_H]

I have no experience in diagnosing noises, so I hope someone can figure this out. From inside the car it sounds like halfway between a flutter and a rattle. The video I took with my phone with the window open makes it sound a lot more like a rattle but that's not as bad as it sounds in real life. The sound does not happen at idle or cruise, but only on acceleration. At first I thought it might be an exhaust leak, and then I started to get worried about a valvetrain problem or worse detonation. Like I said, I really don't know the difference between those sounds so I'm at a loss. Anyway, here's the video - please let me know what you think.

Sorry - having problems uploading the video.