I have a 2000 S430 and i was fixing the HID bulb levels when i heard a little Vibration coming from inside of this part.. i held it and this little part had a vib to it then went off after 1-2minutes - any clue what it is and is it ready to die on me? part doesnt look like it sound make any sound or give any vibration.

Location - Driver side.

 

That the infamous purge valve (part of your emissions system) dont worry about it there all noisey even new ones....you can lessen the noise by insulating it with vaccum hose

 

I've been wondering what that was for the longest time. Mine came off it's fastener and makes a clicking sound. I just reseated it and the noise subsided.

Good post and reply. Thanks!