I had the same doubt on "where the sender is".
I can't find a sender as you do but I noticed that on my cooper with chrono pack, even if the reading it's not so accurate, You can appreciate difference between two differents oil: between 5w40 and 10w60 with same external temperature and same engine teperature, you can see the 5w40 is about 8/10°C hotter than the 10w60. So i guess it can't only be a supposed temperature by the computer.
If you cool down the car for a while switching off the engine and disconnecting battery, then you'll reconnect it and restart engine you'll find oil's temperature is not so low (45, 50°C at least)


However friends that installed a dedicated oil cooler didn't see big differences on the chrono pack gauge...

 

''However friends that installed a dedicated oil cooler didn't see big differences on the chrono pack gauge... "
My point exactly! I have a Sneed Speed Shop Oil Cooler which has a large surface area and adds at least a full qt. to capacity. It has to be running cooler but the stupid Chrono Pack doesn't show any difference...On track or on the highway.

 

The oil temp on the CAn bus is made up by the chronopack.
Accurate to what ? a thermocouple actually IN the oil ?

 

Although I don't like the idea of not having a true oil temperature sensor, I bet they can calculate the oil temp. fairly accurately as long as none of the variables change (ie. adding an oil cooler.)

They have a ton of information to use for the calculation. They know outside air temperature, coolant temperature, how long the car has been running, rpm, speed and who knows what else to aid in this calculation.

I'll say again, I don't like that it is calculate. It is however interesting to me (in a geeky way) that it can be calculated (within its own limits.)

 

Yeah,interesting...just not accurate. The gauge reads the same that it did before the oil cooler installation. Just because I have a degree in industrial Engineering doesn't mean I'm smart but a good dose of common sense tells me the oil has to be a lot cooler. I suspect the reason is the calculations are based on everything BUT the actual oil temperature.

 

how do you explain the fact that changing oil type the temperature changes?? It's the only thing i can't understand

 

Heck I don't know ... but it is kind of fun to guess. If a different oil causes a change in the rate that the coolant heats, that could account for it.

Another thing to consider is if all other things where equal after the change of oil type. Since I have no idea of what they use to calculate the oil temp. I can only guess. Was the car driven exactly the same way? Was the outside air temperature the same?

This would be a lot easier if they just used a temperature sensor .

 

If we could just determine the resistive range of the oil temp gauge and its wiring, it might be possible to install a real temp sensor and use the existing gauge.

 

Just throwing this out there, and bumping the thread from the dead:

http://www.minicarparts.net/Parts/82_94_0_004_581.cfm

 

Is that the oil drain plug substitute?

 

that is the plug I run for my mini gauges, not the chrono pack, it's not a sub, theres no way to get the oil temp in a chrono pack to read off anything but the canbus.

 

what ggcadc said.
i went with the sump plug sender and an a pillar gauge pod, calibrated to a thermocouple.

 

an FYI, the sensor is made entirely of brass, the threads of mine were falling off(found this doing an oil change), so i'm looking for a new location for the sensor as I dont trust it as an oil plug anymore... any ideas?

i've read through:https://www.northamericanmotoring.co...ut-sensor.html

this is the sensor:
http://realoem.com/bmw/showparts.do?...53&hg=62&fg=95

 

alright, for reference, retrofit kit part number 82 94 0 148 956
went to the dealer and had them print me the installation instructions (From the ASAP referred to on realOEM). The sensor is supposed to replace the oil drain plug. damn! I was really hoping that MINI/VDO had some other magic place to put it.

so the final conclusion is Chronopack- Canbus calculations.

Retrofit kit- Drainplug replacement sender unit.

both fail :/

install PDF if here BTW:http://www.outmotoring.com/images/ho...structions.pdf

 

Could you get one of those Craven Speed gauge sender "tapless" adapters, and double up the oil temp sender with the factory oil pressure sender?

 

This is sort of related and maybe this experience can help someone out...

05 MCS JCW 39k miles

I had an "Issue" a a few weeks ago where by my Chrono Pack's Oil Temp Gauge was pinned.. I checked the oil and found it to be low, and filled it to the proper level.. Then a few days later (after sitting ALL night in 34deg weather) I got in to warm it up for a drive and noticed immediately upon staring that the gauge "pinned" again... Baffled I cautiously drove around that day and kept an eye on it.. .It stayed up all the way and then suddenly started coming down (after driving for an hour or so) to a reasonable level... When I got home I checked the oil and the level was fine..

The next day same thing... Upon starting COLD, the oil temp gauge shot right up.. The after the car "warmed up" it came down... Again I checked the oil level and it was fine...

Day 3.. I started the car, oil temp started low and progressively went up as one would expect and as it usually did.. Since then it has been fine..

I just wrote it off as the sensor acting up or becoming faulty... THEN.... Upon reading this and realizing that the Oil Temp is actually a calculation not a direct sensor, I am now even more confused... Is something else causing the calculation to result in the Oil Temp appearing hi?

ENGINE TEMP, and OIL PRESSURE as well as all other reading never read or did anything odd...

Hope this helps... Or hope someone can lend any insight as to what might be going...