I have a 1998 Honda Civic DX hatchback. It has recently started overheating. I have replaced the thermostat and cooling fan. It still overheats, but faster when the A/C is turned on. It also stays cooler longer when the vehicle is moving down the street but when you come to a stop light the temperature shoots up. The cooling fan fuse is still good. Could it be the cooling fan relay? Radiator? Waterpump? There is no signs of leaking coolant and the oil is not milky.

This link should help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-3.html#post235973

Check/replace the Engine Coolant Temperature (ECT) Switch, which is located on the thermostat housing. The cooling fan not coming on is one of the primary causes for Hondas overheating.