I am recently back into the Disco 2 fold after a short break. My recent acquisition a 2000 TD5 ES Auto is proving a little problematic with steering box problems and now over heating. I hear head gaskets are common? It was in the garage last week for a leaking rocker cover and thats when the problem started. Could renewing the rocker cover cause head gasket problems? or what are other likely causes? in standing traffic the needle rises eventually limiting engine revs and has one occasion disabled the auto box. I have also noted that at the same time the air con and heater seem to be affected (aircon not cold and heater not hot!). Any help would be appreciated. Karl