allanroy: another question... assuming that my engine is old (actually, forget about assuming, it is old), chances are madami na syang mga carbon deposits around the valves and such, if we apply XADO, wouldn't the treatment bond with the crud instead of the surface?

Does XADO has a pre-cleaning method prior to application?

I have no doubt that the ceramic coating will bond to relatively new and clean engines, how about old diesels? Thanks