My girlfriend has a 98' honda civic four banger. It overheats when the car is at idle but not running, was originally overheating while running but just needed fluid. The car will cool down when you turn the heater on though. Bad water pump? Thermometer? It also acts as if the starter is going bad occasionally and then once started wants to stall out. Any suggestions? Checked the alternator its charging at 14.5 volts and the battery is holding a charge. I know the issues are likely unrelated. She ran the vehicle hot with no fluids for at least 3 days, she doesn't understand the importance of simple maintenance or watching gauges!!
thermostat would be my guess. Had a Mustang that did that when the electric fan went out but I wouldn't think that would have as much effect on a little Honda four cylinder.
I am almost 100% sure its the thermostat stuck closed. You can try and hit it with a screw driver or replace it. Shouldn't be bad. You have the 1.8 4 cyl?