I noticed this noise at first some time real soon after 9 passes, most hot laps. I launch at 8150. My butterflys are removed, while the plate it's self is intact. Iacv has mild suction. . . nothing to compare it to though.
It's not my big (street) filter, it gets louder and more echo-ous when the intake is removed fom the throttle body.
I cleaned the manifold and found lots oil, big nasty mess, and oil in between manifold layers, on the gasket.
Sealed it all up, got my tq. back (i'd been missing) but noise is still there. It sounds like a hoover vacuum on meth and drives me insane, it has been said that lots of other people have heard other vehichles with this humming noise. WTF is wrong?????????????????????????????/





thanks in advance for any insight!!

 

if only my speakers worked at my job

 

any body else?

Would a bad IACV ceate such noise?

 

sounds like the iacv is on backwards, lol

 

lol, i know, it wants to / likes to idle high, in the 1500-2000 zone sense this issue arised, I had to let some cable out to manage a 1000 rpm.
It's on an autronic too, in case that matters.

 

well if the iacv was bad, it wouldnt make any noise at all. I seriously sounds like the iacv is backwards. I would take the iacv off and make sure its all clean. also, start the motor with the intake off and plug the iacv port with your finger to see if the engine dies.

 

I did the finger thing, and it doesn't die, it just barely pulls my finger in to the manifold.

And when the intake pipe is off the t.b. you can stick 90% of the palm of a hand over the t.b. and the NOISE GOES AWAY!

 

Give me a shout next time your off work and ill come look at it. I cant tell to much from the video.

 

have you tried a different intake manifold. that one may have a crack or something in it

 

^ Thats what im thinking maybe just a small crack in it possibly or may still have a leak somewhere. Spray some carb cleaner all around it while its running and see if idle jumps up.