I have a 93 LX 2.3L hatchback. It currently has 196k miles on it. I let my GF borrow it for about a year. I recently got it back. Now I am noticing that the temperature gauge is fluctuating pretty wildly. Before, it would hardly ever go above the second mark above 130*F. Usually it would stay in between the two marks above 130*F (sorry, I don't know the increments). These days, it is anywhere from two marks above 130*F to two marks below the red zone. I can drive the car and watch the temp hand go up and down. When I'm driving down the road, the temp hand goes up. When I let off the gas, it goes down slightly. Other times, I can idle and it goes up. It is hard to predict. I recall a few weeks ago, I got stuck in traffic due to a wreck. The car was idling for at least an hour and I had driven it probably <10mi before encountering traffic. The temp gauge would slowly go up until it hit a little above mid-way and the fan would turn on. The fan cut off after a minute, temp slowly going back down, then temp goes back up, three minutes would pass, fan would come back on. I told my dad about this. He replaced the thermostat and both temp sending units. My dad thinks it is fine, but it has never done this before, and I have much experience driving that car. The temp has always been pretty low, except on the hotter days of summer. I don't see how the car will NOT overheat this summer. I do know that I accidentally put a lot of antifreeze in the radiator and basically didn't put any water in after (I didn't know any better at the time). It wasn't a full tank of antifreeze - maybe half a gallon. I'm told that's fine because there is some antifreeze/water mixture in the block. Could it need more water and less antifreeze? Or does it need a new water pump? I'm mostly concerned about it overheating in the summer. Note: I am in NC with a mostly mild winter so far.