Okay, so I just took out the low temperature thermostat and fan switch that the previous owner installed. I went to the dealership and got OEM ones and installed them. Now here's my new problem. Fully warmed up at idle I'm at around 195 degrees and the temperature needle gets almost to halfway. When I'm driving the temperature drops to about 183 degrees and the temperature needle drops to the first mark. Is this normal or is something wrong here?

 

And if it helps I'm running a fluidyne radiator

 

Sounds okay. Did you bleed the cooling system?

https://honda-tech.com/honda-civic-d.../#post39830585

 

I did not. I will in the morning and report back. But isn't that a bit much for the needle to drop?

 

For what its worth my temp needle sits steady around 3/8 of the way up. If i turn on the heat and let the car sit at idle the needle will drop down to the first line or so. It doesn't produce enough heat to keep up.

If im driving i can crank the heat and the needle will stay steady around 1/4.

 

Your thermostat may be bad.

 

+1 on bleeding, if you have air in the coolant it will definitely cause fluctuations in the temp gauge because of air pockets

 

Bleed it and see what happens. I've rarely seen new thermostats go bad. I know mine stays about 3/8 up all the time.

 

Its always been this way, old thermostat did it. Replaced with new and nothings changed. Its only when i turn the heat + blower to full and let it sit at idle. Really only a problem in the winter when trying to de-thaw.

Sorry about mini thread jack

 

Could it be because I have a CTR cluster swapped into my EM1 and the temp needle might need to be re-calibrated? With my del sol I had I had to adjust the fuel needle for it to read accurately when I swapped clusters

 

You wanna take that gamble on a freakin needle in a cluster or would rather fix the issue?

You do know there is a way to test the ECT right?