I am currently having similar issues with my car. Oil level at minimum warning, check the dipstick, oil is perfectly filled, full.
I changed out the sensor and still occasionally get the warning. Last one was 2000km on new oil.
I am thinking I might pull the harness for the connector to the oil sensor apart and clean the contacts.

At a loss otherwise as to the problem, the sensor didn't fix it.

 

It appears that there are others that are having the same issue with the message popping up even after changing the sensor. Can anyone shed some light on this issue?

 

Have you checked the codes on the module (INPA)? Is your battery charged over 75%? Did you try to disconnect the battery for a while? Have you done a test on the alternator? Did you clean the connections? Checked for broken/cracking wiring? These are the things I would check if I put a new sensor in and it started after an alternator change.

 

When I get a chance, I will run the car and disconnect the sensor to see if that causes the same low oil warning or if it warns of a sensor failure. I haven't had a chance to trace the wiring on it yet.
Cleaning and greasing the connection, while seeing what fault comes up, is the next step.
I know from years of e36 ownership that a lot of bmw issues stem from grubby connections.
If that isn't the problem, then I'll have to trace the wire run to the sensor, looking for a short.

 

There is a well-documented issue with the oil level monitor giving false readings during cold weather driving, primarily where short trips are involved. Condensation builds up in or around the sensor and prevents it from reading accurately. The best remedy is to give the car a good hard run on the highway for a half hour or more (running at 4-5000 rpm).... then remove the oil filler cap and allow the vapor to escape (with engine idling).

 

I have had a chance to drive the car a fair bit recently. The weather has been warm (25-28c) so I don't think condensation is an issue. Also I've done some longer highway runs so there wouldn't be any moisture in the oil. The oil breather/ separator is new and works properly.

I managed to get the false "oil qty at min" warning to trigger again when driving the car fairly hard, on a twisty road.
At the moment the only guesses I have are either the oil is taking too long to get back to the sump under high revs or perhaps it is foaming so the sensor pings it as low.
Or, maybe driving hard causes the oil to slosh too much and the sensor gives a low indication.....but if this was the case, I would expect it to be a more commonly known issue.
Still working on it!
S

 

Shizam, I sincerely hope it is nothing worse. I have heard about oil pumps going bad on the cars although I'm not sure if there is any correlation between that and the oil level sensor error message. Any body else ever hear of such a correlation?

 

Maybe a bad oil pressure switch not working properly?

Fairly cheap part. I replaced mine because of a leak but not because of error message. good luck

 

Are we talking oil PRESSURE sensor or oil LEVEL sensor? They are not the same and actually independant.

Salut, Bob p.

 

OP is having an issue with the oil level sensor from what I understand.