why is my intake making a whistling sound when I give it gas or blip the throttle ?

I have a stock intake, I took out the rubber "Y' snorkel at the bottom of the intake and it started to make a noise.
I put it back on there , but its still making that noise.

its my 1990 civic si.

 

clean your air filter?

 

cause you are sucking in air.

 

You have PM...........

 

Its the throttle air adjustment screw just above the throat of the throttle body...
It has vibrated clock wise over time and now the tip of the screw acts like a reed and resonates this sound. Fought this problem for 6 months before i found the problem......turn that flat head screw counter clockwise about 1 to 1 1/2 turns and the sound will go away and your idle will smooth out a bit as well.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rex-Si &raquo;</TD></TR><TR><TD CLASS="quote">You have PM........... </TD></TR></TABLE>

thanks, I'll try adjusting the idle screw.