a post mostly about temperature dots

[radix023]

so I've recently changed the device I'm using for Torque and setting things back up got me thinking about what I've been seeing with regards to temperature.

The temperatures displaying in F on torque for oil, coolant and intake are displayed with one decimal place, so : 132.8F or 138.2 F. And also the steps displayed on torque from the ECU were always in the same step of 1.8 degrees. So since everything else on the car is metric, I figured the sensor and ECU were working in Celsius and indeed it does seem to be.

I idled my car so I could match dots on the coolant display with the temperature provided by the ECU via torque. Here's what I found:

I'll refer to the coolant dots by numbers from the left to the right.
I was only able to determine ranges for six of the sixteen dots.

dot 1 : < 56C
dot 2 : 56C
dot 3 : 59C
dot 4 : 62C
dot 5 : 65C
dot 6 : 67C
dot 7 : 70C to at least 101C

I observed that at the thermostat open at 84C the coolant temperature stayed planted for a few minutes before starting to rise again. I think the difference between the oil temperature (lags the coolant on warmup) may have had something to do with it. Oil temp had to get around 78C before coolant temperature moved up with any speed.

Idling I never got to the eighth dot. The fans will engage and blow the radiator before it turns. Since I was idling/parked for safety I am not sure when that one hits. I'll have to be attentive when driving empty roads to see if I can figure that out.

So this confirms that the dots are nonlinear. The 260 limp mode is likely 127C and that *might* be the 16th dot ( > 127C).

The seventh dot is two left of the stem of the thermometer on the display for quick reference.

One of the other things I changed was I turned on the voice stuff on torque and that gave me new info. It now announces when it has reached operating temperature. That's dot seven. When it got there, the idle had dropped to 650 RPM the fuel flow to 0.5 gal/hr. That is, below dot seven the ECU keeps the revs higher than 650 but at temps within seven it idles at 650.

That's all. I hope you found my mild OCD jag interesting...