Vulcan VN900 Classic, 2009, 13000km high pitched whistling/chirring noise seemingly from gearbox in 2-5th gear, goes away when I close the throttle or engage clutch - what can that be?

SOURCE: whistling noise under the hood of my Honda civic.

Thhis noise could be a mutitude of issues. If you have some dash board spray, try spraying some on the top pully staying away from the fans and belts. Also position your face away from the expected spray. Water can be used but it not as affective. Then let me know what happened. Later DRRXR :)

SOURCE: high pitch whistling noise in engine compartment of 2005 envoy

There may be a small hole or cut in a vacum line or possibly just loose. Also make sure the air filter box and the big hose to it are secure and clamps etc are tight. Pulleys and belts can make a high pitch sound also.

SOURCE: VW GOLF 1.4 1999 S. Gearbox makes whining sound at idle

No good news on this one I think
Your whining sound problem is the Layshaft bearings in the gearbox are badly worn. It also seems that the baulk rings are damaged on 5th gear.
John

SOURCE: 2004 honda odyssey making whistle noise

Did anyone find out this problem! I have a 2003 and got the same problem!! please help

SOURCE: hi my rx8 is makin a grinding noise from the

What?! Really! The noise goes when the clutch pedal is depressed! So the noise goes when the release bearing (throw-out bearing) is engage? So how would that be a release bearing/clutch problem? If it didn't make a noise until the clutch pedal was depressed, it would be the release bearing! In other words its the input shaft bearing and/or counter shaft bearing in the gearbox. Stop giving people bad advice