You hear people argue that the head gasket is a one time fix given the improved gaskets but in the real world it isn't. How long it lasts depends on which gasket and how well it was done. It's just a design flaw of the engine, i.e. cast iron block and alloy head in such a long engine. Lots of cars have had to have two or more head gaskets even with the updated gaskets. Dealer mechanic once admitted to me that the MB head gasket part was inferior to those available through jobbers. It's not really a DIY job which to me is the principal argument for a 119 motor.