If your fan doesnt come on then you prob have a bad temp sensor. What I suggest doing (and I have done this with every civic I have had) is unplug the little wiring harness that clips into your temp sensor (its on the thermostat) then get a wire strip both ends and stick each end in each side of the harness. That creates a loop that makes your fan turn on when you start the car, and will stay running the whole time you are driving. I've noticed that it does keep your motor considerably cooler.. if you want a picture LMK i'll post one up