weird random high pitch squeal

[adebiase]

Hi to everyone. I`m new here and i need your help.
My GS500 a couple of days ago started making a very weird noise. It doesn`t matter whether is moving or just idling, the noise is there. Also, it doesn`t matter if engine it`s cold or hot, it`s doing it regardless. Now, it`s not always doing it but come and goes at random.
The hardest part is to describe it. It`s like a high pitch squeal, not loud but is there, coming from the upper part of the engine.  It sounds like some loose metal round washer is vibrating (and ringing) between the bolt and nut but i haven`t seen any. I can`t think of anything. I exclude piston clearance or valves. I`m more into thinking it`s the cam chain tensioner that is not doing a very good job. I`m using an automotive stethoscope but haven`t been succesful yet.
Does anyone have any idea?
thank you

[scratch]

Welcome!

How's your oil level? Squeeling sounds more like metal rubbing past rubber to me. Either something is not getting enough lubrication or something came loose enough to contact something else that it shouldn't, like the plastic/rubber camchain guides.

[Roadstergal]

http://www.gstwins.com/forum/viewtopic.php?t=9022

[adebiase]

The oil level is perfect. If it  I wanted to avoid opening the valve cover because I`d need to replace the gasket but i`m afraid i have no choice.
I`ll wait a bit though.

[scratch]

You shouldn't have to replace either the breather cover gasket (unless it tears) or the rubber valve cover gasket to remove the cover to inspect what loose parts may potentially be under there.