Re: XF Falcon - running problem
My wifes XF had problems running rough - particularly on idle. Had me stuffed and I tried everything including replacing the carby, resealing the inlet manifold, spark plugs, leads, etc. The main problem was that it seamed like one cylinder was not running when idling. In the end it turned out to be a worn hydraulic tappet. It was so badly worn that if you sit it on a table it leans. You can check by removing the rocker cover and running the engine and watching each tapet. It will be quite obvious that one looks different, plus there be less oil spilling onto the valves.