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Do our cars have true oil temperature sensors? Calculated vs. measured oil temp?

Bobby Boucher

Passed Driver's Ed
Location
Seattle
Car(s)
Golf R
Hello. New 2019 R owner here.

Looking through some documentation for the Polar FIS, I'm seeing references to a "calculated" engine oil temperature & "measured" engine oil temperature. What's the difference? I'm guessing "calculated" may be for cars that don't have a true oil temp sensor, or providing some sort of "stable" readout, similar to an idiot light? The oil level sensor from ECS seems to indicate it measures both level & temperature:

https://www.ecstuning.com/b-genuine...YRfNjq23iWpvTma66uWQNIbEjXRjHA9xoCsG8QAvD_BwE

And if both of these do exist on our cars, which does the info cluster display? Seems pretty "measured" to me.
 
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golfdave

Autocross Champion
Location
Scotland (U.K.)
Car(s)
Mk7 Golf GT Estate
My 1.4lt has an actual oil temp sensor in the bottom of the oil pan...I think yours will have the same...

As for Polar FIS...I returned mine a few years ago as although it was supposed to be just released & all ok for the public (I got one of the first batch), their software was still in pre "beta"...I hated the way they "cut" into the album display so that two of the text lines are smaller than the others & everything self centres all the time & the display looked like an over active accordion!
 

Bobby Boucher

Passed Driver's Ed
Location
Seattle
Car(s)
Golf R
My 1.4lt has an actual oil temp sensor in the bottom of the oil pan...I think yours will have the same...

As for Polar FIS...I returned mine a few years ago as although it was supposed to be just released & all ok for the public (I got one of the first batch), their software was still in pre "beta"...I hated the way they "cut" into the album display so that two of the text lines are smaller than the others & everything self centres all the time & the display looked like an over active accordion!
The entire "experience" feels severely half-baked to me, from their website to their instructions, but I'll give it a shot.
 

golfdave

Autocross Champion
Location
Scotland (U.K.)
Car(s)
Mk7 Golf GT Estate
Here I though the one on the bottom of the pan only measured level.

On the EA211 & EA888 its "Oil level & oil temperature sender G266" in the bottom of the sump pan..basically a combined item..
 

langer

i fix teefs
Location
Baltimore
On the EA211 & EA888 its "Oil level & oil temperature sender G266" in the bottom of the sump pan..basically a combined item..
Huh. Didn't realize there was a level sensor. I assumed it was like my mkv, where you didn't know until it was too late and you lost oil pressure.
 

scrllock

Autocross Champion
Location
MI
There's actually a few "temperatures" depending on what you're looking at. There's the raw sensor value, the modeled value used for the gauge, and then several other modeled values used for various things (torque limits, pump control, oil pressure model, fans, evap activation, turbo calcs, etc). If you have full ecu logging access you can view any of them, otherwise decide if you want to look at the oil temp as it is in the bottom of your pan, or what the white coats think it is in the block.
 

dlaunde

Ready to race!
Location
USA
There's actually a few "temperatures" depending on what you're looking at. There's the raw sensor value, the modeled value used for the gauge, and then several other modeled values used for various things (torque limits, pump control, oil pressure model, fans, evap activation, turbo calcs, etc). If you have full ecu logging access you can view any of them, otherwise decide if you want to look at the oil temp as it is in the bottom of your pan, or what the white coats think it is in the block.
Not to revive a dead thread, but you seem to have the knowledge for a question I have had since installing my VADpro gauge.
The VADpro reports the Engine Oil Temp and not the "Normal" Oil Temp that the VW MFI and my AccessPort report.

The Engine Oil Temp tracks similar to the regular Oil Temp until about 170/180 and then the Engine Oil Temp rises faster and levels out around 225-240 when driving hard/extended time (whereas the normal Oil Temp shows 205-215).

Is the Engine Oil Temp parameter a true reading or a calculated one of what the actual temperature is inside the engine?
 

aaronc7

Autocross Champion
Location
USA
Car(s)
17 S3
It's a good question, I have an Audi, but I notice a difference between what I see on the cluster versus Accessport or similar logging tool. I think the cluster is showing some sort of averaged sensor reading and the accessport/tool is showing a modeled value.

I actually looked into my tune file (2017 S3) and it appeared that it was set up such at toil (oil temp) == toil_mdl (modeled oil temp) and that both were modeled values. Which basically took the sensor reading, plus some other math that took things like coolant temp, engine rpm and load/airmass into account. Just a guess, but I'm guessing it's trying to model the expected temp of oil as it's actually passing thru the engine at some point, not temp at the bottom of the pan.

Back to your question... without knowing PID parameter it's polling it's hard to say. I looked up in the manual which PIDs are available. There's 4

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dlaunde

Ready to race!
Location
USA
It's a good question, I have an Audi, but I notice a difference between what I see on the cluster versus Accessport or similar logging tool. I think the cluster is showing some sort of averaged sensor reading and the accessport/tool is showing a modeled value.

I actually looked into my tune file (2017 S3) and it appeared that it was set up such at toil (oil temp) == toil_mdl (modeled oil temp) and that both were modeled values. Which basically took the sensor reading, plus some other math that took things like coolant temp, engine rpm and load/airmass into account. Just a guess, but I'm guessing it's trying to model the expected temp of oil as it's actually passing thru the engine at some point, not temp at the bottom of the pan.

Back to your question... without knowing PID parameter it's polling it's hard to say. I looked up in the manual which PIDs are available. There's 4

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Thanks for all that!

The VADpro is polling whatever sensor/PID the Access port uses for the Engine Oil Temp parameter (as that value on the AP matches exactly what the VADpro is reporting)

I know the Oil Temp parameter (a separate one from Engine Oil Temp) on the Access port is the exact same parameter value that the Infotainment/Digital Cockpit reports.
 
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