Is it making a ticking noise?? Mine was doing it a little while ago. I thught it was just the really cold weather. Bill suggested lubricating it by putting some Marvel Mystery Oil in the input lines. But I hadn't heard the noise for a week or so after I first noticed it. I heard it once again a couple days ago. But if it'* your solenoid, you should be able to change that on a 93. The 94+ you'd have to replace the whole canister. I believe the solenoid is like $10.
Anyone else? I think I'll wait till spring and see if this continues on mine. It may be cold related.