[StorminNorman]

Hi Everyone,
My 2006 325xi (3.0L N52) said it needed oil on my way to work yesterday but on the way home it was fine. It showed 1/4 up the display. I added some oil anyways and then it showed 100% full. Then about 1 Hour later it only showed 1/4 up the display again. Is something wrong with my car because it keeps changing it's mind about the oil level? I don't want to blow my engine!

[csupernova]

make sure you park on a flat ground before checking the oil level. I never had problem with the sensor in my 2006 e90.

[Efthreeoh]

Okay, new owners never read the manual I guess, or search the Forum.

Here's how the e-dipstick works. First off, it doesn't work like a mechanical dipstick because it is not a direct-read device. The bar scale in the gauge cluster is only reporting the level of the 7th quart (i.e. the top quart of oil) in the engine, which is analogous to what a mechanical dipstick shows with the hatch marks on it. So when the e-dipstick is reporting 1/4 of the bar remaining it means the engine is approximately 3/4 of a quart low.

The system takes a measurement of the oil level over time. It does not instantly read a new oil level when you add in oil. The system needs time to take a new reading it is not fast-reacting to new oil levels. The system provides the last known reading of the oil level until it does an update. So you can read a 1/4 quart low, add in a 1/4 quart and take a measurement right away and the system will still show 1/4 quart low. The owners manual tells you to only add in 1 quart of oil once the CBS shows the "+1 QT" notification. You should not add oil in less than 1 quart amounts or you'll get confused on how much oil to add. Only add oil in once the "+1 QT" notification comes up. Once you've added the oil just drive the car normally and take a reading some time later like a hour (of run time) or even a day later.

You need to understand the oil level reading system is calibrated to report low oil level in 1-quart increments and to be replenished in 1-quart increments. Use it the correct way and you'll never have an issue. I suggest that right now, jut wait until the system reads "+1 QT" and then add in a full quart and let the system recalibrate.

In other posts I've gone into detail on how the system works and the engineering principles behind it, you can search if you are interested in more information.

[StorminNorman]

Ok. I'll just wait for the +1 quart message to appear. Thanks for your help.

[UncleWede]

I always wait for the +1 to stay on for 3 continuous days before I feed the beast.

[Efthreeoh]

Per the owner's manual, BMW recommends that once the "+1 QT" notification comes on, to replenish the oil level with one quart of oil within 120 miles of the notification appearing.

[UncleWede]

For me, 3 days is less than 120 miles. SOMEtimes it goes out and doesn't come back on for a few weeks/months. . .

[Bavarian Tech]

N51/2 usually take 2 quarts when +1 pops up..

[Efthreeoh]

Originally Posted by Bavarian Tech

N51/2 usually take 2 quarts when +1 pops up..

Nope.