Yes I have a 2003 v6 accord. I've replaced everything....thermostat, ac condenser, radiator, ac fan, and water pump. When sitting in drive thru or stuck at a red light my temp gauge moves up past the halfway mark. It never goes into the red. When I start driving it goes back down to below normal. Is the a relay, sensor, or chip that might make this happen? Am I over looking something? Please help. I've done a block test too and checked head gaskets too.

 

How's your coolant level? Are you loosing any?

 

Not really. I keep a gallon of water in car. If I ever have to add it's about 1/4 of jug. Replaced radiator 5 months ago and they filled coolant.

 

Just me but if you are having to add coolant on any sort of regular routine something isn't right....I replace the timing belt/water pump/ect on one of mine ~30K miles ago and have checked it but have not had to add a drop.

When the car is cold, not been running in a while, check the level in the rad. If low top it off. Turn the AC off, set the heat to MAX and turn off the blower motor inside the car. Start the car up and let it run. Keep an eye on the temp gauge, if it ever starts to climb towards 3/4 hot, shut the car off.

While the car is running, do the cooling fans cycle on - this could take ~25 minutes. They should as the temp gets ~ 1/2 and be sure BOTH fans run.

If the fans run. Shut the car off and let it cool for a good while -hour at least. Re-check the coolant level in the rad - be careful, hot coolant will burn you. If the level in the rad and the overflow.

I'm trying to figure out if:

1) there is a coolant leak letting air into the system, could be small and take time to "show up" in the levels in the rad and overflow
2) are BOTH cooling fans working

I'll assume when the rad was replaced there was a new rad cap installed.