hey guys i have a question. i have an 02 town and country that's overheating. so far i have changed the thermostat and radiator as well as flushed the system and it still overheats. weird thing is with the cap off the coolant level will drop significantly in the radiator and i have to refill. while driving the temp needle goes up and i usually shut it off. im puzzled on this one. i took the car to a repair shop and he did a block test and it came back fine. and replaced the radiator cap. and it still does it.there are no leaks on the ground and he said he has no idea whats causing this. any ideas im stumped. i was thinking of replacing the water pump but don't want to keep funneling money blindly into it. thanks for any input! also i sent in an oil sample and was told i possibly had a bad head gasket or intake manifold gasket due to the high levels of coolant in the oil, but the mechanic said its fine.