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BMW E36 M3 S50B32 oil and water temperature senders

Posted: Wed Aug 06, 2014 9:35 am
by rodgling
Hi,

Has anyone got data on the resistance / temperature behaviour of the stock BMW S50B32 oil and coolant temperature senders, to save me having to remove mine and boil them in a saucepan with a multimeter attached?

cheers

Posted: Wed Aug 06, 2014 12:01 pm
by Support
its worth testing with our standard bosch calibrations built into the software/firmware... these are very commonly used for OEM sensors.

Kind regards,

Support - Andy

Posted: Wed Aug 06, 2014 12:12 pm
by rodgling
Thanks, I've tried these without success.

Posted: Mon Aug 11, 2014 11:02 am
by Seiz
With software like scantool connected to the ODB and Monitor Lite beside , he must make the temperature reading / voltage.

Posted: Tue Sep 30, 2014 12:53 pm
by osborni
I did a quick google search and there are lots of folks who have taken data on Bosch sensors. The trick is to find the right one.

However, since they are resistance based sensors, hooking up a pull up network to the sensor will likely mess up the data the ECU and the R-T part receives.

I'd suggest installing a separate sensor just for your data collection. You can drill and tap the thermostat housing or, on some BMW heads (I know the US S52 motor, not the euro B32), there are unused ports under the intake manifold you can use. You can also use the heater loop to tap for a sensor.

Personally, most folks just tap the thermostat housing. Take care with a drill and tap, the housing isn't very thick and you'll need to tap it slowly and try the sensor to ensure it's a tight fit.

Posted: Wed Oct 01, 2014 11:22 am
by rodgling
Actually BMW use a dual temperature sender for the coolant (two sensors in one four-wire package), so the ECU reads one sender and the stock dash (or dash2pro) reads the other independently.

So happily this isn't an issue, I've now got the RT dash working fine with the stock S50B32 sender (I calibrated it by removing it and boiling it in a saucepan with a thermometer).

Posted: Sun Mar 22, 2015 5:31 pm
by oveberild
Hi rodgling

Can you post the calibration data for the s50b32 sensors on here?

Rgs
Ove

Posted: Mon Mar 23, 2015 1:46 pm
by rodgling
For oil temp I've got:

3.5C 2891 Ohms
16.6 1473
40 527
50 366
60 239
65 206
70 165
75 145
80 132
85 102
90 89
95 77
100 66

For water:

3.5C 28412 Ohms
16.6 11048
50 2270
60 1438
65 1160
70 1000
80 711
90 536
100 397

Stock fuel senders are about 10 Ohms empty, 269 Ohms full (they are wired in series so you need to double this if using both).

For all of these I've used a 1k resistor which seems about right.

Hope this helps.

Posted: Thu Apr 16, 2015 11:45 am
by oveberild
Thanks for the numbers.

Hope you can help me with another question :)

I connect up the RPM readings from the ECU (black wire) to the low level rpm input on the DASH2 PRO..
But on idle it shows about 2500 rpm on the dash, any idea what i`m doing wrong?

Posted: Tue Jul 14, 2015 12:16 am
by oveberild
Hi rodgling,

Do you have the volt readings you use in the fuel sensor chart?

Rgs
Ove

Posted: Tue Jul 14, 2015 4:13 pm
by rodgling
Assuming they are wired in series and you are using a 1k resistor, this should result in a voltage into the dash of about 0.1 - 1.75 V for empty - full if my maths is correct.