My son has a 01 accord and while sitting, at an idle the temp guage shows it is over heating. There is plenty of coolant with no leaks, both fans are working. while in park you can bring up the rpm's and it cools back down. Once again at an idle it starts creeping back up.While driving there is no problem, only when the car is stoppedDo you think it is the thermostat???

 

Coolant temp. sensor. and/or thermostat.

 

When the engine is cool, take off the radiator cap and check that the radiator is filled with coolant. If you decide to replace the thermostat, get one from the honda dealership, because they open up at the proper temperature and are relatively inexpensive.

 

How high does the temperature gauge get? Its normal for it to go up some.