Hey guys i recently bought a k&n series 77 intake kit for my '97 4.6. And at idle in cooler weather it made a really loud annoying bellow. I called k&n and they said it was common with my type of intake, because of some kind of flaps on the inside of the intake. Has anyone else experienced this? I sent mine back and I'm looking for a different brand that doesn't make this noise, anybody got any ideas?

 

I have that same intake and never have that problem.

 

I have the same intake and I have heard that bellow also I did a search on here and found that the sound most likely was coming from the IAC. Do the search and there is lots of info how to clean this part or replace it.