Hey guys, recently my 1990 Civic ee9 started to make a noise from the intake manifold. Taking out the admission air tube, looks like its from throttle body. Everything is stock, and dont have a clue on what to do ir be. Can some1 Help plzz.
IDdle is unstable when engine is warm, 1000/1500 rpm.. no check engine light.
Ear the noise from the vídeo.(Will upload when i convert from MP4)
The picture with the Yellow circule, its not that hole, but the 1 on top execly like that.

Not that, is the 1 execly like that on top

 

I would check for a vacuum leak. They will whistle whenever you use cold air intakes sometimes as well.

 

I Will check for leak, noise is made by the air indeed, hás i cover the top hole and noise goes, also when i put pedal 2 the metal, (air goes in) noise goes.

 

After seaching for the origin of the noise, found out its the EACV/IACV. Gonna try to clean it to see if noise goes