A couple days ago I started seeing the temp rise a little over average and heard the fans on at idle w no ac/heat on. Next two days the temp would get medium-high, then stay there or go back down to normal. Replaced the thermostat and it keeps normal temp at idle, but when driving overheats quicker than before the thermostat change. Weird thing is the coolant level never seems to move?

btw I used a tool to take all the pressure out of the coolant lines.

 

Have similar random overheating issue, Nissan dealer said it was the radiator so they replaced the radiator, thermostat and gasket but the temp gauge still jumped up on me once (after all the work) and went back down after the fans kicked on. Only thing left to replace is the water pump unless there's a sensor in there somewhere. Car does not act like it's overheating, nothing seems abnormal other than the gauge rises, the fans kick on and then the gauge drops and the fans kick off. At first they said there was nothing wrong with the car, coolant good, no codes. Tech that worked on the car said it could be head gasket but the car appears to be running normal. I think they guessed when they said radiator but what other possible solutions are there?

Any related input would be welcome, similar experiences and/or solutions...?

Thanks,
Jason