I have a rattling noise that sounds like it is coming from right in front of the motor... It sounds like a pulley rattle like one is going out but I can't tell which one it is... Idler... Alternator... etc...
Anyone else have this issue?? Or a guess?? Or a way to diagnose it without putting my hands or other limbs in harms way?

BTW >> 08 6.7 with 50K miles and yes I have changed the oil.... Maybe it is the sparkplugs...lol

 

Try putting slight pressure on the injector lines, could have a loose dampener, although it's usually one of the ones in the rear (#5?) that gives people trouble.

 

Anything else it could be??

 

water pump

 

I am thinking it could be the fan clutch... Has anyone heard of a fan clutch going out on these motors at 50K?

 

Turbo

 

Take the serpentine belt off and try each item by hand. Anything else is just random guessing.