I've found the bleed screw on the rad... Anyone know if there's one anywhere else? Last ditch attempt at fixing before it goes to the stealers for work....
Rummaging via the search box, "...black plastic knob top rear right of engine..." or words to that effect, dunno if it's right. One suggestion is to backflush by attaching a water hose to the bottom, uh, hose and removing the top.