hi. new here and would like some help. i have a 91 prelue si B21A1, i degreased the engine with a pressure washer and right after that i get this whistle noise. it happends when i put it in gear. its a stick shift and it whistles in all gears as i give it gas and foot off the cluch its ony for 2 to 3 secends but it just dont sound right. if you need more info i will let you. anyone pease help..... THANX..

 

Check your intake and intake manifold for something missing.