Hi. My Grand Voyager 3.3L overheats in hot weather, and especially with air conditioning running. If the radiator is full, but there is little to no fluid in the overfill reservoir, it will contain any "spillage", but still overheat. When there is any fluid in the reservoir, then it expands too much and spills out on to the engine (belt area). Fans seem to be working- what should I check next?

Tim

If the fan is working for sure and it overheat even while at highway speeds it is probably the thermostat, clogged radiator, or the water pump.