Ok newbie here needs help. Suppose to be leaving town this coming Friday morning and last night my truck started to make a "different" noise. I open my hood and used my mechanics stethoscope to track it down. Best description I can give you is a buzzing noise that I can actually feel on injector line #5. Its actually vibrating! The truck is not running any different, no warning lights on although possible the tail pipe is blacker then normal. Not sure about it. So anyone experience this before that can help me find out whats going on.