Oil question - fill level related

[3Pedals_6Speeds]

My 2013 came up with (1st since I've owned it, almost 2 years) a message indicating it was low on oil, below the scale it shows. I pulled into the dealership, bought a liter of oil and poured it in. I drove 0.5 miles home and as I pulled into the garage it alerted me that the oil was overfilled. I pulled it onto my storage lift, removed the drain plug and drained off 0.5 liter (I measured). I got the car back on the ground, performed a check, and it says it is still over filled.

How sensitive is this thing to oil level? I assumed with a huge reservoir that 0.5 liters couldn't take it from "add oil" to "too much oil".

[Scrippy]

It's not very sensitive but it's easy to add too much. I add in quarters and as I drive keep forcing level checks. Eventually it gets accurate. FYI next time don't drain by the plug. Open the oil filter cap and suck out the oil in the housing. There's is easily 8floz. In there. It's less messy and easier IMO. Lol order a syringe shot when at a pool in Vegas, they're perfect for sucking oil out.

[TrueToBMW]

I had my oil at the low level line, and added about 0.7L over the course of 2 or 3 drives, i always fill my car to the halfway mark, since overfilling can cause some serious issues.

With that being said, adding the amount of oil I did took the car maybe 5 to 8 heat cycles to register; next thing I know I'm at the full line, so me being super picky, i proceeded to drain about 300cc of oil, and once again, took about 6 heat cycles to register that it was now at exactly the half mark.

My long elaborated point being, it'll take the car a few start ups and some driving before it will register the new exact oil level (maybe you can do a manual measurement via the idrive vehicle settings menu, not sure).

Anyway, that's just been my experience with the amazingly awesome super high speed electronic dip stick

[3Pedals_6Speeds]

Originally Posted by TrueToBMW

I had my oil at the low level line, and added about 0.7L over the course of 2 or 3 drives, i always fill my car to the halfway mark, since overfilling can cause some serious issues.

With that being said, adding the amount of oil I did took the car maybe 5 to 8 heat cycles to register; next thing I know I'm at the full line, so me being super picky, i proceeded to drain about 300cc of oil, and once again, took about 6 heat cycles to register that it was now at exactly the half mark.

My long elaborated point being, it'll take the car a few start ups and some driving before it will register the new exact oil level (maybe you can do a manual measurement via the idrive vehicle settings menu, not sure).

Anyway, that's just been my experience with the amazingly awesome super high speed electronic dip stick

Glad to hear this about the heat cycles. I decided after posting this to let it sit a day, drive the beater, and check again after work tonight. Won't be multiple heat cycles, but hopefully will give me a better read.

I think I'll also try extracting from above this time. I assume a syringe and a flexible hose would suffice? If so, how long on the hose?

[nrubenstein]

Also, the oil level sensors are frustratingly inconsistent. Mine frequently seems to "burn" half a quart, and then a few days later, it'll find it again.

[grantaf]

I've had my 2011 M3 for just about 3 months now. I haven't done a oil change yet, and it is still at the max fill level since the day I got it. Not overfill, but exactly at the max point. I've always wondered if it would move down at all but nothing yet.

[Z K]

If you have overfilled it, the oil level will say "> MAX". Otherwise you are fine.

And I hate the oil sensor. It takes many drive cycles before it reads the oil accurately.

[TrueToBMW]

Originally Posted by 3Pedals_6Speeds

Glad to hear this about the heat cycles. I decided after posting this to let it sit a day, drive the beater, and check again after work tonight. Won't be multiple heat cycles, but hopefully will give me a better read.

I think I'll also try extracting from above this time. I assume a syringe and a flexible hose would suffice? If so, how long on the hose?

Just pop the oil filter cap off, put a rag around the filter housing as not to spill oil along the housing, and then just grab a simple 10cc syringe and suck it out, don't really need a hose or tube, just carefully remove the oil filter itself and set it aside on a clean non-porous surface, syphon out a few hundred cc and you should be all set.

[monterey]

The last time i did an oil change i sucked out the oil from the filter's canister and forgot to refill it with oil. When i started the car, it rattled pretty bad from oil starvation for a good 3 secs. It freaked me out. I don't think draining the oil from the canister is a good idea.

[TrueToBMW]

Originally Posted by monterey

The last time i did an oil change i sucked out the oil from the filter's canister and forgot to refill it with oil. When i started the car, it rattled pretty bad from oil starvation for a good 3 secs. It freaked me out. I don't think draining the oil from the canister is a good idea.

Good point, I should have mentioned to not fully drain it, what I was saying was that I took out about 150cc - 200cc, and then if need be I would reinstall the cap, cycle the engine, and then repeat the process to get another 150-200cc's of oil out.

[Scrippy]

Are you guys sure the oil sensor operates on heat cycles? You can force update in idrive or from BC stalk. I have forced resets while driving and after about the 3rd or 4th it recognizes my additional oil I've added. Never once do I turn my car off. That is why I'm asking about the heat cycle statement.

[TrueToBMW]

Originally Posted by Scrippy

Are you guys sure the oil sensor operates on heat cycles? You can force update in idrive or from BC stalk. I have forced resets while driving and after about the 3rd or 4th it recognizes my additional oil I've added. Never once do I turn my car off. That is why I'm asking about the heat cycle statement.

I've never done it via the idrive settings, but I'd imagine you can do it that way, and have it read it multiple times once the engine heats up, rather than running the engine multiple times to get multiple readings.

[Candide13]

Originally Posted by Scrippy

Are you guys sure the oil sensor operates on heat cycles? You can force update in idrive or from BC stalk. I have forced resets while driving and after about the 3rd or 4th it recognizes my additional oil I've added. Never once do I turn my car off. That is why I'm asking about the heat cycle statement.

I think everybody has experienced some amount of confusion with the oil level measurement system, but nobody really knows how it works.

Myself, I think that part of the problem is that the system does not just show the measured oil level. Rather, it also tries to guess whether you have filled it. This would explain why the level jumps from low to full even if you only put in half a quart. I think the system detects that you added oil, and then assumes for the time being that you added a full liter (as it is German). Then it slowly realizes that the oil level is less than that, so you observe the level falling over the next few hours of driving.

Anyhow, ever since I owned an Alfa with huge oil consumption (that engine got replaced eventually), I have been paranoid about oil levels. For the M3, I just add half a quart when the sensor reads low; otherwise I try to ignore its inner life.

[Scrippy]

Originally Posted by Candide13

I think everybody has experienced some amount of confusion with the oil level measurement system, but nobody really knows how it works.

Myself, I think that part of the problem is that the system does not just show the measured oil level. Rather, it also tries to guess whether you have filled it. This would explain why the level jumps from low to full even if you only put in half a quart. I think the system detects that you added oil, and then assumes for the time being that you added a full liter (as it is German). Then it slowly realizes that the oil level is less than that, so you observe the level falling over the next few hours of driving.

Anyhow, ever since I owned an Alfa with huge oil consumption (that engine got replaced eventually), I have been paranoid about oil levels. For the M3, I just add half a quart when the sensor reads low; otherwise I try to ignore its inner life.

The car has no idea you added oil and for sure it is a measurement from the oil level sensor in the bottom of the oil pan. There is no contact switch monitoring the oil cap, so the car would have no idea oil was added. I believe the measurement issues are a result of moving oil in a moving car. The measurement is not taken until operating temp is the only for sure thing I know.

[wyatth]

I had my bearings swapped yesterday and oil filled (9qt). Oil sensor in dash said OK. I drove home 35 miles and it told me to add 1qt. I was going to let it sit over night and check the reading again when it's cold, but now it seems that is ineffective? Bummer if I have to warm it up again when it's a bit low just to confirm how much I should add.

[Candide13]

Originally Posted by Scrippy

The car has no idea you added oil and for sure it is a measurement from the oil level sensor in the bottom of the oil pan. There is no contact switch monitoring the oil cap, so the car would have no idea oil was added. I believe the measurement issues are a result of moving oil in a moving car. The measurement is not taken until operating temp is the only for sure thing I know.

I did not mean that there is a sensor in the cap, it's a software thing. Basically, there is an oil sensor but its reading is not displayed directly. This is because thermal expansion etc would make the reading go up and down all the time, even when the engine is warmed up. So instead the basic sensor level reading is the input into a software routine that also takes engine temperature and other stuff into account, all before eventually displaying its best bet on oil level reality on the dash.

So, once the sensor reads a level clearly above the last reading, the software system concludes that a quart has been added and acts accordingly. Well, that's my theory at any rate..

[Z K]

Originally Posted by wyatth

I had my bearings swapped yesterday and oil filled (9qt). Oil sensor in dash said OK. I drove home 35 miles and it told me to add 1qt. I was going to let it sit over night and check the reading again when it's cold, but now it seems that is ineffective? Bummer if I have to warm it up again when it's a bit low just to confirm how much I should add.

If you've had the oil pan removed, it may very well be low. There is a lot more oil drained when you do that. But to be sure, get a few readings before adding oil. Even if it is low, 9 quarts is plenty of oil if you're driving normally.

[xander_g]

I add half a litre every time it asks for a full litre, never had an issue

[Thik]

Originally Posted by xander_g

I add half a litre every time it asks for a full litre, never had an issue

That's an M-car 101. Should be mandatory lesson for all M3 drivers.

[Three Pedal Steve]

My 2013 M3 seems to burn about a quart of oil every 5000 miles. That's when I change the oil. At the 4000 mile interval I might add 1/2 quart.

[wyatth]

Originally Posted by Z K

If you've had the oil pan removed, it may very well be low. There is a lot more oil drained when you do that. But to be sure, get a few readings before adding oil. Even if it is low, 9 quarts is plenty of oil if you're driving normally.

Thanks. And to "get a few reading," that's a few cold start cycles, yeah? Bummer it has to warm up to give an accurate reading, unlike old school dipsticks (ugh).

[wyatth]

Started it up this morning, consistently read, “minimum +1L.”
Added .75L, now it reads, “ok - max.”
Should have started with .5L like you gents advised. At least it's not overfilled as the 1L likely would have been.