It's a 2001 Honda Civic DX. I've been driving normally around town and after awhile the temperature gauge goes all the way up. The car doesn't seem to be overheating however because I noticed if I am at a stoplight and rev the engine up for a few seconds and let the rpms drop again, the temp gauge drops back down to normal.

I've changed the thermostat, checked all the hoses, checked the fans(which are working) and bled the air out of the system. I've looked through the forums and I don't see anyone with similar symptoms. I'm stumped as to what to look for next. Thanks.

 

Actually my car just overheated a few days ago, didn't seem to have any symptoms, until I was almost home I smelled coolant sure enough temp started rising. Pulled over, checked under the hood and coolant res cap had blown off somehow and made a mess with the coolant all over the place. Don't understand how it might have happened, i'm thinking fan switch died on me, but then again i had replaced it not long ago. Sorry for the lengthy story, but has your car ever done this?

 

@ Tombomb661- Do a diagnostic on the gauges:

1. Push and hold the trip/reset button
2. Turn the lighting switch ON
3. Turn the ignition switch ON
4. Within 5 seconds, turn the lighting switch OFF then ON then OFF again.
5. Within 5 seconds, release the trip/reset button, then push and release the button 4 times repeatedly

If, during the test, the needles don't sweep from min to max and back to min then replace the clustor. If at the end of the test the odometer reads "Error" there is a communication problem between the gauges, MCU, and the ECM/PCM. Usually it'a bad wire/connector.



@ drigo951: Sorry bro, that's a classic symptom of a blown headgasket. Have a shop confirm by testing for exhaust gases in the coolant.