Hello Guys. I need your help. I drive a 10-year old Civic. The temperature gauge shoots up if I don't accelerate. It even shot up to the red line already yet there is water in the radiator and engine is not overheating (no steam, etc). The gauge goes back to normal is the car is steady at 2000rpm. At Idle, I have to pump gas at 2000rpm for the gauge to goes down. What are the possible issues? Thanks very much