2002 Kia Sedona

Engine Cooling problem
2002 Kia Sedona 6 cyl Two Wheel Drive Automatic 98700 miles

My van just started to overheat. I checked fluid level and it is full. With heater running on full, it runs cooler when I sitting still than when I am moving. Any ideas?
Pastor Carl
June 4, 2009.

With the heater on, the heater core acts like a small radiator helping to cool the coolant.

Does the car only overheat when sitting still? If so, is the cooling fan coming on? Also if it overheats at anytime, have you tried replacing the thermostat or flushing the cooling sustem?

Let me know.