I have a 2003 eddie b edition. The Service engine light came on and showed # 4 bad so we replaced plug and coil. It went off after we reset it. Did good for awhile. Then it started running a little hot but didnt get to the red line. Now the service light is back on and the overflow keeps filling up while driving and it overflows. No water in the oil or on the oil cap. It isnt smoking or anything. I have looked for leaks and everything. Does anybody have any advice for me?
Could be stuck/faulty thermostat, bad radiator cap or faulty water pump. Look closely at water pump. There is a weep on it. See if there is any sign of leakage. (Dried antifreeze around weep hole). If you see any its time to replace the water pump.