TexRodeo

I have read all over the internet to no avail and there is not an exact scenario that is like this with a 7th Gen Civic.

OK, So here Goes, When I recently purchased "Sian", My '03 Civic EX Sedan. I first noticed with the cooling system that there didn't seem to be any color to my coolant, so I would assume that the Radiator and the coolant bottle would both be full of mostly water, that's one thing that I know I should address soon with the heat of another Hot and Humid North Carolina Summer coming fast.

Again, I have no Service Engine Light Illuminated or Any other warning lights of any kind so I am kind of doubting the ECT Sensor is at fault as it never tripped a light, But again, Auto-Mechanic I'm Not. So my question is would there be something other than the afore mentioned cooling system needing to be flushed that would cause this gauge not to move at all?

I have heard the electric fans come on, right on cue...So I doubt very seriously that there is an issue with the cooling system so much.

But this inoperable gauge does seem like yet another on a short list of fiddly little or minor repairs that need doing that I have run into thus far.

Any Ideas I should check?

Larry

Wankenstein

Stick a (hi-temp) thermometer in the radiator or use an infrared heat gun (extrenally) while engine is at operating to to make sure coolant system temperature is within spec.

Drain and fill coolant, then bleed air out of coolant system with front of car on jack-stands as high as possible. Put climate control on max heat, fan off. Rev engine intermittently a few times during air-bleed process tohelp expell bubbles (air). Use either Hondo (blue dye) coolant or Pentosin PentoFrost A3 (blue dye) coolant.

This issue may or may not throw a CEL light (code). Bring it to Autozone or other parts store and ask them to an OBD2 scan on it to rule out unseen codes. If a code is found write it down and post here.

Yes. A fautly ECT temp gauge (cylinder head), break in wiring from ECT to ECU, a faulty temp gauge (cluster), and possibly more.

That is good.

Just imagine how many issues a 14 year old American or European car would have?

ezone

CEL, does it work at all? It should come on when you first turn the ignition on as a bulb check. Some people disconnect the light, break or remove the bulb, wire the light to something else so you can't tell it's got a problem......


Code reader, read fault codes.
Better scanner, read live engine data to see what the ECT value is as seen by the PCM.

IF the PCM shows a good ECT value (170-210*F when warmed up) but the gauge does not work.... do a gauge cluster self diagnostic test and see that all 4 gauges make full sweeps during the test.


tl;dr
See if the PCM data shows good temperature.
Make sure the gauge needle works