hey guys, I got a Civic that keeps filling up the overflow reservoir and getting hot on the temp gauge. The car is a 94 civic with a 98 civic gx motor and is automatic. So when I check the radiator fluid its always low after 30 minute or more drives and the reserior is full. I cant see any leaks and I've checked it while it's running. Also when on a decent drive the temp gauge goes to the hot line but never over and then it goes back down and then up again. I've put a new thermostat in it which I have tested to make sure it works, New radiator cap, flushed the radiator, and also done a block test because I was told by everyone it was probably the headgasket. I've noticed that when the radiator fan comes on it only comes on for a few seconds and then shuts off, not sure how long it is supposed to come on for ? looking for ideas whatelse it could be ? any help would be appreciated , thanks .