I took apart a burkert 2822 solenoid because there was debris trapped inside it and i couldn't blow it out. i opened it up and when i put it back together and plugged it in I hear this buzzing noise. any idea what this means? I'll take pictures later today.
The coil itself may be bad as well. I've got a brand new 6011 that has hummed from the start. If you take the coil off of the armature body and insert a metal rod through the hole (a dental pick in this case) the coil hums and buzzes like nobody's business. The vibrations from this unit definitely come from the coil moving, not the armature/manifold.