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Engine Oil Reading - RPM increases

6K views 12 replies 4 participants last post by  markl53 
#1 ·
I just noticed this morning that while getting the engine oil level reading, the rpms increase from the normal 700 rpm to about 1100.
 
#2 · (Edited)
Yes, that is part of the grand design. Out of curiosity, I've asked several dealer SA's how this function works but haven't gotten a definitive answer. It's possible that the N55 has some kind of split sump where the oil level sensor is located and the engine rpm is increased so a scavenge pump can fill the part of the sump where the sensor is located. One SA told me that the oil level sensor measures oil level by the amt/volume of oil pumped thru the sensor in a set amount of time and at a set rpm. I guess that would work, but I think the flow would be affected by oil viscosity which is gong to change due to a number of factors (fuel dilution, temp, length of time oil in service). I don't really know. Anybody know? Anybody care?
 
#3 ·
I have never noticed an rpm change while checking my oil level. Possibly a coincidence you are noticing?
 
#4 ·
The rpm's definitely increase from about 750 to about 1100 during the level measurement. The Owner's Manual for the 2012 5er only covers 520 and 528 (duh) for measuring specific level (detailed measurement as they put it), but the manual notes that during detailed measurement, the idle speed is increased somewhat. I think the same message re increased idle speed is given in the iDrive during the measure-oil-level selection process.
 
#5 ·
I have a 2011 535i. I will try it at idle tomorrow. I typically check the level while driving on a level road at a constant speed. Once warmed up, as soon as I select the oil level screen, the green line is already appearing, there is no delay or message that the idle will speed up. If I try and check the oil level before the engine is sufficiently warm, the only message I see is "measuring oil level".
 
#6 · (Edited)
OK, absolutely no change in rpm when performing an oil reading at idle. When are you guys stating that the rpm increases? When you select the "Vehicle Status" menu and go to the oil read sub-menu? When I do that, assuming the engine is sufficiently warm to report the oil level, the green oil level bar appears immediately, there is no pause for a reading to take place -- because it has already occurred. I believe when you press the oil button, it is simply accessing information already fed to the computer. The only time there is a pause is if you try to check the level too soon after you start the car. Then, as I stated in my previous reply, the message just says "measuring engine oil level". At that point, I usually move off that screen and come back later if I really want to see the level. Also, if I leave the Vehicle Status selection in the oil level position, as soon as I re-select Vehicle Status, the "engine oil level OK" is already visible, even before I see the green bar.

In conclusion, at least for my 2011 535i, there is no special "process" which increases rpm when doing an oil level reading.
 
#7 ·
Same here, no idle change when checking the engine oil level.
 
#8 ·
Mayhaps the mechanism is different in the 2011 f10. It sounds like the '11 f10 had an oil level measuring mechanism similar or identical to the n54. Can you measure the oil level while the car is underway?
 
#9 ·
Yes, it works idling or in motion. I'm still wondering how yours works. Do you navigate to the oil level screen and then wait as the engine revs up and then displays the level? Sounds kind of strange and unnecessary. And it does seem to work exactly as my E90 335i did (N54). Can't you leave your Vehicle Status menu on the oil level sub-menu and when you go there, the oil is already displaying? Or do you have to initiate something each time you want it to be measured?
 
#10 ·
You have to initiate the level measuring after going through a couple steps on iDrive. The next to the last step or screen says the car must be in park, on a level surface, engine warmed up, etc (I can't remember if it says the idle will increase slightly, stay off the gas). You then select "measure" through the iDrive, the idle increases to around 1100 rpm, and the next screen is a horizontal bar that starts to gradually increase with an increasing percent figure as the measurement is taken. It takes about a minute or two (seems longer) for the measurement to complete. Then the final screen shows the familiar vertical bar, like a dipstick, with the oil level.

You definitely can't measure the oil level while the car s in motion.
 
#13 ·
Totally different then, must have started with 2012. Thanks for the detail.
 
#11 ·
I agree 100% with m6pwr.
 
#12 ·
I think BMW probably changed the oil level sensor somewhere along the way and that has changed the level measuring procedure.
 
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