hi all , do any of you knowledgeable diesel buffs out there know what the part is below? the engine is my 2007 sprinter 316 5 cyl . the part is attached to the bottom of the airbox and has a rubber tube going to the turbo . i took as good a photo as i can but it is in a really hard place to get at. when i turn the engine off this little thing makes a sort of buzzing sound for about 15 seconds , not too loud but i had the bonnet up at the time and noticed it. doesnt seem to make any difference to engine while driving and no lights on the dash. any ideas ? regards sean