Intake Manifold Rattle

[irocdupi]

Ok, so my mechanic and I have been trying to figure out what the rattle on my truck could be, he doesnt think its a timing chain rattle because even though it has the 2800 rpm rattle it diminishes once the truck is warmed up, maybe it could be a catalitic convertor since they make a click click click noise but also we hear a like shush shush shuhs khhh kkhhhh noise commig from the intake manifold near the front of the truck and drivers side. Any ideas,

 

[eeprete]

do you have the 4.6 or the 4.0?

 

[irocdupi]

4.0 91000mi