Wrote in a few weeks ago with my 2000 Disco II overheating. I did head gaskets, water pump, radiator, thermostat, all hoses and complete flush. Still overheats fast after driving (2 minutes) It will idle forever without overheating. #6 cylinder misfire detected. I removed heads again and installed 2 new complete heads. SAME THING. Could I have dropped a sleeve from overheating before? How can I test this or find out if I dropped a sleeve. When I perform a leakdown test I have pressure through the reserve bottle. Not good. What should I do now? Pull the heads back off again??? Thanks.