Temp guage problem (repost)

[RickPA]

I had the thermostat off the car. Is the collant temp. sensor the gray capped plug directly behind the thermostat? If it is I turned it while poking around and now the temp. guage doesn't show the proper reading. In particular it doesn't read as cold as it should and rises faster than it should but it does not read hotter that the engine really is.

In short it seems to have lost its reference and it's range.

Is there something I need to do to recalibrate it? Is the orientation of the sensor critical or did I break it when I turned the upper part of it?


Thanks

 

[prybylo]

I don't know the answer to your question, but I have a theory.

The temperature sensor is right near the outlet of your heater. And the inlet to the heater is right near the water pump (i.e. tends to be cold). So the temp sensor goes thru bigger swings than the engine does because it is sensing water, to at least some extent, that is coming out of the heater.

I tested this when my thermostat wasn't working right. Let the truck get to operating temperature, and then accelerated while in Park. The temp gage and the temperature of the heater water (as sensed by my hand on hose) dropped immediately. I can't believe the temp of the engine would be that responsive and I didn't note any change in the temperature of the hose out of the engine to radiator.

So if you did change slightly the location or orientation of the temp sensor, it might make a big difference in what your gage reads.