Temp gauge

[Teh_Loserer]

Temperature gauge on my 2006 doesn't move off of cold.

I've run the car long enough to get warm, the upper radiator hose got hot, and the heater was blowing hot.

I don't think it's the sensor because I was told that it would run rich as a result, and the car seems to run fine. I let it idle for half an hour to warm up, then revved it a few times, never smelled rich at all. Also, no check engine light, no warning messages, nothing else amiss at all.

Before I pull my DIM and look at part numbers, does anyone else have any suggestions? Anything else to possibly check?

[Astro14]

I wouldn't rule out the sensor..."smelled rich" isn't exactly precision diagnostics...and "hot" to the touch may be true, but that's the thermostat...CEL? Warning lights? If it's the same sensor for the gauge and the ECU, then how would the ECU know that anything is wrong?

I would replace the sensor.

[Teh_Loserer]

If it's the same sensor for the gauge and the ECU, then how would the ECU know that anything is wrong?

If anything was wrong with the sensor circuit, would the ECU not detect that and throw a CEL? Similar to the way that when an O2 sensor goes?

And the bit about the hose was ruling out the thermostat. I'm well aware that "smelled rich" isn't precision at all, but the way it was explained to me was that it would be rich enough to produce smoke. It never even smelled rich, let alone smoked.

[Astro14]

I think you ascribe too much sophisitication to the ECU. What would be wrong with a failed sensor that it could detect? The sensor fails to cold...and the ECU only knows that it is displaying the resistance associated with cold temp...so, since that value is in the range of normal...no problem...ECU runs the engine in open loop...not like a choked carburetor...just a bit on the rich side...you'll never know that the ECU is open loop unless you've got a good scan tool and can see what the ECU is seeing for temp.

When O2 sensors go, they often (but not always) give values that are out of range. Not necessarily so with this one.

I would replace the sensor. If you really want to get into diagnosis, remove the sensor, place it in a pot of water with a cooking thermometer, and using a good multimeter, measure the resistance vs. temp as you heat up the water. I don't know the value, one of the guys with VADIS might be able to help with that.

But I would just put a sensor in...

[Willy]

The engine coolant temperature sensor's resistance values are:
15040 Ω at -20°C
2450 Ω at 20°C
318 Ω at 80°C
These figures are for a MY2004 2.5T XC, but I think 2006 is the same.
Willy

[Teh_Loserer]

Got it. I'll throw a sensor in and see how that goes. Thanks for the input, it's much appreciated!