98 civic si (its canadian so american ex) has recently started making a very odd sound when it warms up and I have no clue what it is but hopefully someone here does
https://youtu.be/4SsIXIzHyPs
should also mention, the idle fluctuating happens from start up usually, sometimes it doesnt but it usually does

 

For anyone with this sound. A rock had the vtec solenoid stuck open, not sure why it caused the sound but I took it off and got a little rock out and the rod popped out and all symptoms are gone.