The problem is when driving the temp guage moves up and down between the middle of the guage and 3/4 to the top. Is this usual for a Prelude or as I think there is a problem with the termostat or temp guage. Another thing is after driving even in cool weahter the fan runs after the cars engine has been turned off. Any ideas what is going on?

 

The cooling fan is supposed to run after the car is off, if its hot. Sounds like the thermal sensor might need replaced. There are 2 thermal sensors on the 3g lude. The one at the bottom of the radiator that controls the cooling fan which sounds like the one you need. Or the second posibility is the one on the thermostate housing that controls the temp gauge. Just out of curiosity before you get it to all that, is your coolant full?! Sounds more like you need coolant. Trust me on that! The 3G is so temperamental.

Wayne

 

does it get hotter when you stop, and then once you start moving again it goes back down? if that is the case, then you are probably just low on coolant. that happens to me every now and again.

 

Thanks everyone for the info!