Rep Power: 0

Changed the thermostate about 2 weeks ago. Got a tune up the next day. The third day while idling for about 4 minutes the temp gauge started to rise quickly. Turned odff, then back on ... no problems. This happened a few more times. Drove the car about 60 miles away via the highway, everything smooth. As soon as we got onto a city street, it started overgheating. Bought another new thermostate and radiator cap, but its still ocurring, but more frequently and takes more time to cool down. Also the coolant cap was left off after the 1st thermostate was replaced .. it was put back on 3 days later. No overheating prob. Prior to thermostat. What could it be?

 
Rep Power: 219

Probably your radiator fan switch located on the housing for your thermostat. Are your fans switching on without A/C? If not then that would probably be it.

 
Rep Power: 323

did you bleed the air out of the cooling system? could be an air bubble. take off the rad cap ( when cold) start it up and let it run (while watching the temp) until the fans kick on. then put the cap on and you should be fine. if the fan doesnt come on and it starts to get too hot then its probably something having to do with the fan circuit.

 
Rep Power: 253

Its probably an air bubble..jack the front end of your car fill your radiator up. Turn your car on and heat as well and fill her up.

 
Rep Power: 254

take off the radiator cap, turn on your motor and turn your heater all the way up. put a brick on the gas pedal to hold it at about 2.5k rpm. keep refilling as needed. i bet its a air bubble.

 
Rep Power: 209

I would check the circuit for the radiator fan. Above 30 to 35 mph the radiator fan is not needed since there is enough air flow. If you can drive 60 miles on the highway without a problem I would be surprised if there is an air bubble in the system. It's possible that while replacing the thermostat one of the connectors for the fans was loosened or that the sensor happened to fail.

 
Rep Power: 0

You know you could just move the throttle cable with your hand brick seems kind of intense lol.

 
Rep Power: 0

ok so I had an 02 ex with the same problem. thermostat changed twice, radiator once. Went to honda and an independant dealer. If you can grab ahold of the hose that runs from the coolant tank to the engine, it's the gauge itself that is ****ed. If its pushing coolant out of the reservior and you tried releasing the air bubble problem, then you may have gotten a bad replacement thermostate. Mine was a bitch and took 6 years and at least three mechanics to fiure out. Good luck!