Loud humming noise from air intake.

[Gregroe75]

I have replaced the PCV valve. Did not stop then I replaced the idol air control valve and it is still humming. I'm just wondering if my manifold could possibly be messed up as well. I am just a tube mechanic and have never messed with this side of things before. HELP

 

[dsayers116]

IAC valve.
It will get louder.
Easy fix. Replace the PCV hoses as well. They get crusty and fail, too.