I ran across a small WIF that was only able to get to 20F. Tstat was calling so LLS was open and unit running. Once I got back to the roof the liquid line was making all this chatter. I ran back downstairs. to discover the noise coming from the LLS valve. While energized the coil chattered like heck, stop for a while, then chatter a lil more then stop, etc . Customer said the chattering noise has been happening for sometime off and on.

Can those plungers get 'stuck' inside the valve? (This unit has had multiple surgeries) OR...Is there such a thing as a weak coil? Yes proper voltage was delivered to coil.