All the pieces are in the lower city. Dammon has a Diabolic Forge (does he even USE the thing?!), the Steel Watchers recognize her as a defective Watcher and have Enriched Infernal Iron, the Steel Watcher tells you exactly what is wrong with her engine which is apparently almost a prototype for what keeps them running, the Gondians improved upon the design and could easily figure out a way to fix her.
So in theory the quest would have you talk to Dammon, talk to a steel watcher while she's in your party, talk to Dammon again. "Apparently those metal monstrosities running about think I'm one of them and it told me that my 'insert tech description here I can't remember it clearly atm' is what's wrong with my engine." Dammon has a eureka moment, "Of course! But honestly.. that seems to be a bit outside even my skill level.. Tell ya what. Go see if you can save those Gondians from Gortash's whip. If you can pry apart the watchers, and get them out safely, try and get one of their engineers to come here. Between me and some gnome tech geniuses with the Diabolic Forge in the house, we'll fix that heart if it's the last thing we do."
Done and Dusted. Hell they could probably go the route of making her a whole new engine. Which unlocks her blue flames full time. (Don't judge me she looked hella cool.)
Also Dammon losing his ability to forge items out of Infernal Iron in Act 3 is really suspicious.
