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cyl head temp

Higgs Boson

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Oh. Well x amount of fuel and air will produce x amount of BTUs. From there you would need to know the water/coolant ratio with the radiator volume and you could get the maximum BTUs it could remove and still maintain x temperature. The water/coolant ratio is why you need the temp sensor. Of course exhaust egt and natural engine radiation factors in making it not direct.

Every path from point a to b to me is linear. I guess a direct temperature relationship may not be the best way to describe it. Lines can have curves cross over themselfs go one direction then another or just be straight. The BTUs produced and BTUs radiated is or should be a direct relationship other wise the engine is soaking them up and that's not a good thing after a certain point..
changes in temperature, altitude, and humidity are going to affect the radiator's cooling ability/performance a lot different than the engine's so there's another variable or two for you.

I think there is only a CHT sensor but it won't be too hard to figure out about the CHT vs radiator temp sensor, just call and order them from the parts dept.

RockAuto.com only lists a CHT sensor, for example.
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markmurfie

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Quote:
Cylinder Head Temperature (CHT) Sensor
Note: If the CHT sensor is removed from the cylinder head for any reason it must be replaced with a new sensor.

The CHT sensor is a thermistor device in which resistance changes with the temperature. The electrical resistance of a thermistor decreases as temperature increases, and the resistance increases as the temperature decreases. The varying resistance affects the voltage drop across the sensor terminals and provides electrical signals to the PCM corresponding to temperature.

Thermistor-type sensors are considered passive sensors. A passive sensor is connected to a voltage divider network so varying the resistance of the passive sensor causes a variation in total current flow. Voltage that is dropped across a fixed resistor (pull-up resistor) in series with the sensor resistor determines the voltage signal at the PCM. This voltage signal is equal to the reference voltage minus the voltage drop across the fixed resistor.

The CHT sensor is installed in the cylinder head and measures the metal temperature. The CHT sensor provides complete engine temperature information and is used to infer coolant temperature. If the CHT sensor conveys an overheating condition to the PCM, the PCM initiates a fail-safe cooling strategy based on information from the CHT sensor. A cooling system concern, such as low coolant or coolant loss, could cause an overheating condition. As a result, damage to major engine components could occur. Using both the CHT sensor and fail-safe cooling strategy, the PCM prevents damage by allowing air cooling of the engine and limp home capability. For additional information, refer to Powertrain Control Software for Fail-Safe Cooling Strategy in this section.
End quote.

So it must be air charge temperature vs engine coolant temp.

The values make sense that way as well. If it was temp vs temp it would not make any sense. They shoot for 200* ECT and 100* IAT.

Ford really really likes complex algorithms that rely on one sensor.

speed of vehicle, or fan speed as well.
 
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16RRGT

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Thanks markmurfie... appreciate it. Wonder if its covered under warranty?
 

DrZed

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... odd because my scanning tool shows the CHT 10F lower than what is displayed on the dash... Scanning software calls it "engine cooling temperature - corrected"
 

FreePenguin

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... odd because my scanning tool shows the CHT 10F lower than what is displayed on the dash... Scanning software calls it "engine cooling temperature - corrected"
my obd2 displays the same temps as the digital dash on mine. Been no discrepancy between those two

only thing that isn’t true is the afr.

I have a afr true, and afr commanded,

neither of those match what my car says is 13.8-14.3, my scan gauges will show like 14.8 etc

F683AC79-BE68-4528-91F3-437A8C9E7959.png
 

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DrZed

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... that must be Forscan.. I downloaded it onto iOS and my Carista WIFI and generic ELM WIfi adapters wouldn't work. Bummer...

My car is a '21, wonder if they changed the algorithm or something... the data log does say "corrected", maybe it is indeed a calculated value from the cylinder head....


my obd2 displays the same temps as the digital dash on mine. Been no discrepancy between those two

only thing that isn’t true is the afr.

I have a afr true, and afr commanded,

neither of those match what my car says is 13.8-14.3, my scan gauges will show like 14.8 etc

F683AC79-BE68-4528-91F3-437A8C9E7959.png
 

FreePenguin

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... that must be Forscan.. I downloaded it onto iOS and my Carista WIFI and generic ELM WIfi adapters wouldn't work. Bummer...

My car is a '21, wonder if they changed the algorithm or something... the data log does say "corrected", maybe it is indeed a calculated value from the cylinder head....

OBD Fusion, IOS. paired with the forscan wireless dongle, the 100dollar one on amazon.

I just read my comment, the engine coolant, is the same temp as the CHT on my dash* is what I meant.
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