Today I put a can of Seafoam through my truck (works wonders, I swear) and while my truck was belching ungodly amounts of smoke, I noticed Seafoam smoke coming from the engine compartment. So, naturally I ran over to investigate, and I saw that there was smoke coming from the driver's side manifold. There is a pipe that runs from the exhaust manifold, covered in some sort of heat-shielding fabric (maybe?) to something near the top of the intake... I've added two pictures to try and help, the red arrow shows where the smoke was coming from and I've circled the pipe in white.
Would that be a loose connection? Bad manifold? Blown gasket of some kind?