Hi. I have an 03 honda civic lx that was repoed June 2014. Before it got repoed it was overheating and I needed a new engine. I replaced the radiator but didn't replace the engine and it got taken away. I got the car back April 2015. I got a rebuilt engine and everything was ok. But now the temp gauge is wanting to go up but only at idle. So I replaced the fan switch, relay, and tried burping the coolant system. I hooked up the fans to the battery and they work. Now idk what to do it's still wanting to go up and when I drive at high speeds it goes back to normal. I'm about to pull my hair out from stress with this. Please help