Oil temp sensor

Bnks334

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Dec 1, 2016
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So is the oil temp sensor taking temperature before or after the cooler (if equiped)?

Oil temperature senor is located on the driver side of the block near the HPFP. It reads oil temperature from the main bearing oil galley which is clean and then cooled oil. This gives a decent idea of what type of temps you're seeing through the bearings.
 
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Bnks334

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The oil temp sensor is located on the ofh and coolant is basically next to it.

I found this "This sensor is used in two locations on BMW's and serves as both an oil temperature and water temperature sensor. As a water temp sensor it is located in the side of the cylinder heads. As an oil temperature sensor it is located in the side of the oil filter stand at the front of the engine. This sensor determines temperature by changes in its electrical resistance. This information is relayed to your gauge cluster as well as to the DME where the information is used to adjust fuel, cooling fan operation, and vehicle diagnostics."

I am thoroughly confused now and we both seem to be wrong lol. Top oil filter housing sensor is plugged into clean filtered and cooled oil and it is definitely the pressure sensor. I put a new one in when I rebuilt my motor and it is not a temp sensor it is a different design.

The other two you'll have to figure out. Thinking back to when I rebuilt my block, I think the above description may be incorrect. I think the front sensor is coolant and the side sensor is oil. That is what I remember them being anyway.

IF you read through the N55 engine PDF: http://www.1addicts.com/forums/attachment.php?attachmentid=586998

It contradicts the information quoted above and agrees with me. If you look at the side of the engine block where the sensor is located near the HPFP it is way too low to be coolant. I remember it being an oil passage.

This leads me back to my original post that the oil temperature sensor is on the side of the block and it reads clean (and cooled) oil in the main bearing oil galley right before it gets fed through the bearings.
 
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Bnks334

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I am referring to #16 here: https://www.realoem.com/bmw/enUS/sh...-2010-E82-BMW-135i&diagId=11_4447#13627580635

What you quote does not make sense. I think pelican is wrong as is the description in many places. Even the BMW doc calls it both a pressure sensor on one page and a temperature sensor on another page of the PDF I linked (erroneously of course). I have held #16 it in my hand. It is 100% a probe temperature sensor.

The sensor near the the filter cap is 100% the pressure sensor. It is completely different then #16 above. It is a valve (to measure oil pressure) and there is no thermistor on it. Now go look at the front of your engine at that sensors location. It is the coolant temperature sensor and it plugs into the cylinder head. It has nothing to do with the oil filter housing and stays with the cylinder head even when you remove the oil filter housing. See here as well: https://bmw.spoolstreet.com/threads/coolant-temp-sensor.3448/

https://www.newtis.info/tisv2/a/en/...ntrol/13-62-senders-for-control-unit/D7wda78v

As stated in my previous post, there is no coolant flowing through the block where #16 mounts. It can't be a coolant sensor. Not only is it physically impossible for #16 to be a pressure sensor since it's a thermistor, it also doesn't make sense for it to be a pressure sensor since it would not give an accurate picture of oil pressure throughout the motor. There are other oil galleys that could potentially drop pressure and the DME would never see it.
 
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CHINB7

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Nov 24, 2020
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I found this "This sensor is used in two locations on BMW's and serves as both an oil temperature and water temperature sensor. As a water temp sensor it is located in the side of the cylinder heads. As an oil temperature sensor it is located in the side of the oil filter stand at the front of the engine. This sensor determines temperature by changes in its electrical resistance. This information is relayed to your gauge cluster as well as to the DME where the information is used to adjust fuel, cooling fan operation, and vehicle diagnostics."

I am thoroughly confused now and we both seem to be wrong lol. Top oil filter housing sensor is plugged into clean filtered and cooled oil and it is definitely the pressure sensor. I put a new one in when I rebuilt my motor and it is not a temp sensor it is a different design.

The other two you'll have to figure out. Thinking back to when I rebuilt my block, I think the above description may be incorrect. I think the front sensor is coolant and the side sensor is oil. That is what I remember them being anyway.

IF you read through the N55 engine PDF: http://www.1addicts.com/forums/attachment.php?attachmentid=586998

It contradicts the information quoted above and agrees with me. If you look at the side of the engine block where the sensor is located near the HPFP it is way too low to be coolant. I remember it being an oil passage.

This leads me back to my original post that the oil temperature sensor is on the side of the block and it reads clean (and cooled) oil in the main bearing oil galley right before it gets fed through the bearings.
I signed up just to say thank you for the information you posted. Hopefully it will be a help to others as well. BMW does indeed have the oil temperature sensor labeled incorrectly in some of their literature. The oil temperature sensor is NOT at the front of the block below the oil filter housing.

2015 BMW 535xi. I had various codes, all pointing to engine oil temperature. It seems as if the transmission, DME, climate control all want to know the readings from this sensor. My symptoms were an erratic oil temperature gauge, Fan would intermittently run at full speed very similar to when the water pump is failing. The fan speed in my case was directly related to the oil temperature reading being off as the vehicle thought it was severely overheating (it wasn't). My oil temp would bounce from ice cold, to the needle fully pegged and everywhere in between in a matter of seconds. The higher the temperature reading, the louder & faster the fan. Overheating messages on the idrive and cluster.

My oil temp sensor connector ended up being chewed off by a rodent. I believe that both wires to the sensor were shorted out on the block. In order to access the sensor, you have to remove the throttle body and all the intake & charge pipe ducting around it. As soon as you drop the throttle body, you will be staring at the sensor.

Thanks again Bnks334.