okay, so i'm driving down the road other day, when i turn down my music and hear my car making a really loud noise in the engine, sounds almost like loose heat sheild or something. upon further inspection i find that noise is coming from the head, inside somewhere, and what it is i'm not sure. now i know that my ignittion coil #4 needs replaced, but i was waiting on this 4 a bit for financial reasons. I come upon this noise now, and i'm wondering is this just the coil? can they make this kind of noise if they are going really bad. FYI...the car is running fine otherwise.