Hi, I have the same problem with my 2006 X Type 3Ltr, I will try to find a the bleed valve to see if there is air in the system. But today after driving for 15 mins with cold air blowing on me I stopped the engine for a minute and when turned back on there was instant heat, so I think it is more of a valve sticking. Do you know if the S type valve is the same as for the X type? I cant see any X type valves on eBay. George