[YGazis109]

Hey guys, I am at 180,000 miles on my n52...still love it, however I know at 184,000 the oil monitor goes bad, I have heard that you can get a patch from the dealer? Can you guys lead me in the right direction so when I hit that mileage I know what to do, I really don't want to go in my car and see the red oil light going off all the time, like it did in my dads old 530xi n52

[W37V]

Sorry dude, no patch.

However, hass has been experimenting with the code and maybe he ran across the part of the programming that monitors this functionality.

[hassmaschine]

I haven't really looked for that yet, but maybe I'll come across it. However, I haven't looked at anything for the 328i.

[David0ff]

Just so I understand this correctly, are you still able to check oil level after 186?

[fravel]

Originally Posted by David0ff

Just so I understand this correctly, are you still able to check oil level after 186?

My understanding is that you can still monitor the oil level through the menu on the stalk, the CBS just stops giving mileage estimations for how long you can go before your next oil change.

Basically, for those of us that use a set oil change schedule and don't worry about the car telling us when to do it, it should be a non-issue.

[YGazis109]

Originally Posted by fravel

My understanding is that you can still monitor the oil level through the menu on the stalk, the CBS just stops giving mileage estimations for how long you can go before your next oil change.

Basically, for those of us that use a set oil change schedule and don't worry about the car telling us when to do it, it should be a non-issue.

I use my own schedule as well...however I don't want the annoying red oil light on when I get in and out of the car....

[YGazis109]

And fravel is right...you can still monitor oil level, but you can not reset the mileage for your next oil change...so you get a annoying red light saying you are due for an oil change...even when your not...

[David0ff]

Ah ok, thx for clarifying guys, I was worried the whole sensor your go offline and you would have to guess your oil level.

[mike-y]

stupid question - resetting the CBS doesn't work? the light constantly stays on??

I'm at 168k, so I guess this is something I get to look forward to.

[Three_thirty_I]

The local ECU "specialist" that I took my 330i to last year said that they have sorted this out on lots of cars that have come in with this problem - I asked them about this after reading all the hassles that Efthreeoh had with his car back then. But I can't vouch for this since it is simply based on what they said, and I don't know what would different after this. So I am not sure if the CBS keeps working as before, or if it is just disabled and only shows oil level reading. From what I remember about the problem that Efthreeoh had, the oil level reading wasn't correct along with the oil service light that kept popping up. For me, as long as the oil level reading is reliable and the oil service light can be permanently disabled, then just service it at regular intervals which, due to that sort of mileage, would be fairly regular anyway.

[fravel]

My car is at ~135k right now and I just moved to a new apartment such that my commute to work is about 1 mile round-trip now, so I'm betting I'll be more than ready for a new car long before I actually need to deal with this issue.

[hassmaschine]

the closest thing I can find in the code is an upper limit of 655,350km. I don't see anything that indicates a limitation of 300,000km.

It would have to be either a software bug a hard coded limit in the program but finding it there would be very difficult. It could be that it's supposed to run out at 655,350km, but a bug is making it stop at 300,000km instead.

[fravel]

Originally Posted by hassmaschine

the closest thing I can find in the code is an upper limit of 655,350km. I don't see anything that indicates a limitation of 300,000km.

It would have to be either a software bug a hard coded limit in the program but finding it there would be very difficult. It could be that it's supposed to run out at 655,350km, but a bug is making it stop at 300,000km instead.

Hmm.. I wonder if it's a buffer overflow sort of issue.

[hassmaschine]

could be. I doubt it's intentional.

Anyone with a 328i have the same issue? MSV80 uses a different CPU - although how it runs the engine is the same, it would have been compiled differently and possibly used different source code. It might not have the bug, if it is indeed a bug. as far as I know only people with 2006 have seen it.

[YGazis109]

Originally Posted by hassmaschine

could be. I doubt it's intentional.

Anyone with a 328i have the same issue? MSV80 uses a different CPU - although how it runs the engine is the same, it would have been compiled differently and possibly used different source code. It might not have the bug, if it is indeed a bug. as far as I know only people with 2006 have seen it.

Hmmm...it could be just a 2006 issue because my dads was a 2006 530xi...mine is a 2007 328xi so maybe mine won't have the issue...I am hoping lol

[Efthreeoh]

Okay, I guess I'll chime in. The software in the ECU is programmed to stop taking the oil quality data provided by the oil sensor. After 186,000 miles (300,000 KM) the CBS will start resetting the OCI at a lower level than the previous OCI (mine cut down to about 9,200 from a normal 17,000 miles). The next oil change the CBS will only reset the OCI to 0 (zero). Once that happens the CBS starts counting down from zero in negative increments. As of August 2013, when I discovered the issue, BMW reinstalled the latest software at that time with the "patch" that is supposed to take to oil change past due warning out of the engine start and engine shutoff routines so the CBS doesn't constantly inform you that the engine is past due on an oil change.

My car now only notifies at engine start that the oil change is past due. The notification at engine shut down did go away. The CBS counts down in negative numbers. BMW recommends that once the car reaches this condition, to inform the customer to change the oil at regular intervals. I change mine now at every 10,000 miles (down from about 17,500 miles on average). Once the CBS gets to -10,000 I change the oil.

In August 2013 BMW NA opened a PUMA case on my car regarding the software not completely removing the oil change notice. I tried for about 16 months to see if BMW Germany was going to address the PUMA, but they never did. At the time in Aug 2013 BMW NA told my dealership that I had the highest mileage E90 in the USA and it was the first instance of the issue they had seen. Why BMW designed the software this way still remains a mystery to me. BMW has really moved on from me as a customer. I've found the Cadillac ATS as what I would consider a replacement for my 3-Series as it actually drives like a BMW and most of the 2014 and beyond BMWs drive like old model Cadillacs.

After 221,000 miles once the OCI only reset to zero, my oil consumption seemed to drastically change. Basically the engine at 221K used 1 quart of oil about every 10,000 miles. Now it's down to about 6,000 miles. But the pan gasket had started to leak around that time too, but not terrible. In January 2016 I replaced the oil pan gasket. I've not kept super accurate records of oil consumption since the pan gasket change, but will once I change the oil at 300,000 (probably in 2 weeks). Attached is the BMW information I was given by my BMW Dealer who tried to solve the issue.

[Three_thirty_I]

Originally Posted by Efthreeoh

Okay, I guess I'll chime in. The software in the ECU is programmed to stop taking the oil quality data provided by the oil sensor. After 186,000 miles (300,000 KM) the CBS will start resetting the OCI at a lower level than the previous OCI (mine cut down to about 9,200 from a normal 17,000 miles). The next oil change the CBS will only reset the OCI to 0 (zero). Once that happens the CBS starts counting down from zero in negative increments. As of August 2013, when I discovered the issue, BMW reinstalled the latest software at that time with the "patch" that is supposed to take to oil change past due warning out of the engine start and engine shutoff routines so the CBS doesn't constantly inform you that the engine is past due on an oil change.

My car now only notifies at engine start that the oil change is past due. The notification at engine shut down did go away. The CBS counts down in negative numbers. BMW recommends that once the car reaches this condition, to inform the customer to change the oil at regular intervals. I change mine now at every 10,000 miles (down from about 17,500 miles on average). Once the CBS gets to -10,000 I change the oil.

In August 2013 BMW NA opened a PUMA case on my car regarding the software not completely removing the oil change notice. I tried for about 16 months to see if BMW Germany was going to address the PUMA, but they never did. At the time in Aug 2013 BMW NA told my dealership that I had the highest mileage E90 in the USA and it was the first instance of the issue they had seen. Why BMW designed the software this way still remains a mystery to me. BMW has really moved on from me as a customer. I've found the Cadillac ATS as what I would consider a replacement for my 3-Series as it actually drives like a BMW and most of the 2014 and beyond BMWs drive like old model Cadillacs.

After 221,000 miles once the OCI only reset to zero, my oil consumption seemed to drastically change. Basically the engine at 221K used 1 quart of oil about every 10,000 miles. Now it's down to about 6,000 miles. But the pan gasket had started to leak around that time too, but not terrible. In January 2016 I replaced the oil pan gasket. I've not kept super accurate records of oil consumption since the pan gasket change, but will once I change the oil at 300,000 (probably in 2 weeks). Attached is the BMW information I was given by my BMW Dealer who tried to solve the issue.

Aside from the oil service indicator issue, did you not also have a problem with the oil level sensor not being correct at that point, making it impossible to know if your engine had enough oil in it or not - lack of a proper dipstick FTL!

One can only hope that as more and more E9X's reach this high mileage there will be enough pressure for BMW AG to come up with some sort of proper solution.

[Efthreeoh]

Originally Posted by Three_thirty_I

Aside from the oil service indicator issue, did you not also have a problem with the oil level sensor not being correct at that point, making it impossible to know if your engine had enough oil in it or not - lack of a proper dipstick FTL!

One can only hope that as more and more E9X's reach this high mileage there will be enough pressure for BMW AG to come up with some sort of proper solution.

In another thread of the OP's I believe I covered the issue, and mentioned it in the last paragraph of this response. At one point I was concerned that the oil level was not reading correctly because my oil consumption seemed to drastically change once the OCI could only reset to zero. I kept detailed records of oil consumption (by the 1/4-quart) to try and determine if the oil level reporting was random or followed a pattern. It was hard to collect the data accurately since the system doesn't notify of an oil level change until the engine is a quart low. So I would have to get in the habit of checking the oil level weekly (I chose Tuesday). However since I drive about 800 miles a week, my data points for oil consumption could be off by over 1,000 miles, so I was getting some crazy readings on a weekly basis.

I ended up keeping records of oil consumption by the quart, where the pattern showed 1 quart about every 5,000 miles. Since I've repaired the pan gasket leaks, the oil consumption has seemed to go up a bit to about 6,000 miles per quart. To sum it up, I think the oil level function of the oil sensor still works correctly post the 186,000 mile event.

I truly believe that as an owner, if you follow BMW's recommended procedure for topping off the oil level upon the +1 QT notification (i.e. not at intervals less that 1 quart) and let the CBS recalculate the level over several drive cycles, you can learn to trust the e-dipstick.

I think some owners top off too much at quarter-quart notifications, which then they trick themselves into thinking the oil level system is not working correctly. For instance the CBS could be reporting the oil level is 1/4 quart low, but since it only reports in 1/4-quart increments, and depending on when you read it, the oil level could actually be almost 1/2 quart low (the CBS just hasn't tripped yet to a 1/2 quart reading). So you add 1/4 quart and most people not understanding how the system works, expect an instant change to the reading (it doesn't) and get confused; or the system shows the oil level is back to full, then a few days later goes back to 1/4 quart low (because the engine really was almost a 1/2 quart low).

That's why you can read all of my responses in posts about the e-dipstick that I say only top off at full 1 quart intervals once the low oil notification comes up. Owners need to realize that the engine is designed to run at lower oil levels than full and is completely protected. Engines do not need to have a full compliment of oil in the oil sump to prevent oil starvation. If you've ever been inside an engine's oil sump you'll see that the oil pump pickup is almost at the bottom of the lowest part of the pan, so the engine would have to be several quarts low to risk oil starvation (over half the oil capacity in most cases). For an engine to drastically lose oil in a short time/mileage period there would be tell tale signs of a massive oil leak or massive oil consumption and catalytic converter failure.

If anyone would bother to read the owners manual of mechanical dipstick engines, they'd find that it says not to top off the oil level if the reading is in between the lower and upper levels of the marks (i.e. hatched area) and to add oil only when the oil level is at the lower mark. The bar graph of the e-dipstick on BMWs is analogous to the hatch area on the mechanical dipstick. BMW in my opinion has done a lousy job explaining how the e-dipstick works and how to interface with it. BMW's instructions should explain the crossover concept of the e-dipstick from a mechanical dipstick, so as to help those owners who too-frequently top off their engine oil because the mechanical dipstick is direct read and seems more trustworthy. I actually like the e-dipstick because it is a passive sensor. It takes no action from the owner to keep the engine topped off with oil, where as the mechanical dipstick is an active sensor, where the owner needs to check it routinely. In this day and age, most people don't check their oil level.

My 2 cents.

[Three_thirty_I]

Originally Posted by Efthreeoh

In another thread of the OP's I believe I covered the issue, and mentioned it in the last paragraph of this response. At one point I was concerned that the oil level was not reading correctly because my oil consumption seemed to drastically change once the OCI could only reset to zero. I kept detailed records of oil consumption (by the 1/4-quart) to try and determine if the oil level reporting was random or followed a pattern. It was hard to collect the data accurately since the system doesn't notify of an oil level change until the engine is a quart low. So I would have to get in the habit of checking the oil level weekly (I chose Tuesday). However since I drive about 800 miles a week, my data points for oil consumption could be off by over 1,000 miles, so I was getting some crazy readings on a weekly basis.

I ended up keeping records of oil consumption by the quart, where the pattern showed 1 quart about every 5,000 miles. Since I've repaired the pan gasket leaks, the oil consumption has seemed to go up a bit to about 6,000 miles per quart. To sum it up, I think the oil level function of the oil sensor still works correctly post the 186,000 mile event.

I truly believe that as an owner, if you follow BMW's recommended procedure for topping off the oil level upon the +1 QT notification (i.e. not at intervals less that 1 quart) and let the CBS recalculate the level over several drive cycles, you can learn to trust the e-dipstick.

I think some owners top off too much at quarter-quart notifications, which then they trick themselves into thinking the oil level system is not working correctly. For instance the CBS could be reporting the oil level is 1/4 quart low, but since it only reports in 1/4-quart increments, and depending on when you read it, the oil level could actually be almost 1/2 quart low (the CBS just hasn't tripped yet to a 1/2 quart reading). So you add 1/4 quart and most people not understanding how the system works, expect an instant change to the reading (it doesn't) and get confused; or the system shows the oil level is back to full, then a few days later goes back to 1/4 quart low (because the engine really was almost a 1/2 quart low).

That's why you can read all of my responses in posts about the e-dipstick that I say only top off at full 1 quart intervals once the low oil notification comes up. Owners need to realize that the engine is designed to run at lower oil levels than full and is completely protected. Engines do not need to have a full compliment of oil in the oil sump to prevent oil starvation. If you've ever been inside an engine's oil sump you'll see that the oil pump pickup is almost at the bottom of the lowest part of the pan, so the engine would have to be several quarts low to risk oil starvation (over half the oil capacity in most cases). For an engine to drastically lose oil in a short time/mileage period there would be tell tale signs of a massive oil leak or massive oil consumption and catalytic converter failure.

If anyone would bother to read the owners manual of mechanical dipstick engines, they'd find that it says not to top off the oil level if the reading is in between the lower and upper levels of the marks (i.e. hatched area) and to add oil only when the oil level is at the lower mark. The bar graph of the e-dipstick on BMWs is analogous to the hatch area on the mechanical dipstick. BMW in my opinion has done a lousy job explaining how the e-dipstick works and how to interface with it. BMW's instructions should explain the crossover concept of the e-dipstick from a mechanical dipstick, so as to help those owners who too-frequently top off their engine oil because the mechanical dipstick is direct read and seems more trustworthy. I actually like the e-dipstick because it is a passive sensor. It takes no action from the owner to keep the engine topped off with oil, where as the mechanical dipstick is an active sensor, where the owner needs to check it routinely. In this day and age, most people don't check their oil level.

My 2 cents.

Thanks for your response and clarification. I just remember when you had this problem and couldn't remember if this issue was sorted out, or in this case, was just ultimately a suspected issue. I think at the time, I also had a weird thing happen with my car's oil level sensor and this had me very very concerned. From day one when I realised that these damn cars don't have a temperature gauge I noticed that it takes quite a while for the oil level reading to show from a cold start and driving off, so I decided that I would use this as a sort of guide to determine when the engine is warm enough to drive normally. With that said, I check my oil level readings every time I drive the car, and I usually check it a few times. So if there was ever a change in oil level according to the oil level sensor I would see it when it happens. This one particular day, I finally got the oil level reading and it showed it as being on the 50% mark, where the day before it was still showing the 100% mark. Not it can't drop two increments like that in such a short space in time/distance unless there is something wrong, oil leak, burning oil and smoking like a VW diesel (jk). And when I drove it later it kept showing this 50% reading, so it was not an anomaly. That night I took the car for a spirited drive on a quiet stretch of road and all of sudden the oil level was back to 100%, then dropped and settled on 75%.

All that I think could have happened, since it seems that this sensor takes various measurements electronically to determine oil level and condition, there must have been some moisture in the oil that had burnt off (it was warmer spring months when this happened) and possibly had the sensor slightly confused. Have not had this happen again since.

[Efthreeoh]

Originally Posted by Three_thirty_I

Thanks for your response and clarification. I just remember when you had this problem and couldn't remember if this issue was sorted out, or in this case, was just ultimately a suspected issue. I think at the time, I also had a weird thing happen with my car's oil level sensor and this had me very very concerned. From day one when I realised that these damn cars don't have a temperature gauge I noticed that it takes quite a while for the oil level reading to show from a cold start and driving off, so I decided that I would use this as a sort of guide to determine when the engine is warm enough to drive normally. With that said, I check my oil level readings every time I drive the car, and I usually check it a few times. So if there was ever a change in oil level according to the oil level sensor I would see it when it happens. This one particular day, I finally got the oil level reading and it showed it as being on the 50% mark, where the day before it was still showing the 100% mark. Not it can't drop two increments like that in such a short space in time/distance unless there is something wrong, oil leak, burning oil and smoking like a VW diesel (jk). And when I drove it later it kept showing this 50% reading, so it was not an anomaly. That night I took the car for a spirited drive on a quiet stretch of road and all of sudden the oil level was back to 100%, then dropped and settled on 75%.

All that I think could have happened, since it seems that this sensor takes various measurements electronically to determine oil level and condition, there must have been some moisture in the oil that had burnt off (it was warmer spring months when this happened) and possibly had the sensor slightly confused. Have not had this happen again since.

All I can say is that when the car gives the "+1 QT" notification, just add in a quart of oil. I think even at 7 quarts, the oil sump has room for a slight overfill. Every time I've topped off at less than 1 quart, the oil level readings fluctuate from full to less than full. Every time I've topped off at the notification mark, the level remains at full for several thousands of miles. I can't stress enough to just follow the "+1 QT" procedure and the system responds without issues. It's designed to be topped off in 1-quart intervals, as that is what the owners manual says to do. Doing otherwise is just fighting the design and engineering of the car.

I know some knucklehead will come on and disagree (like Clifton) and make an argument, but I've done 21 oil changes to this date, which is probably more than most owners here and I'm about 400 miles shy of 300,000 miles. So by this time I think it's fair to say I'm quite familiar with how to maintain the N52.

Peace.

[hassmaschine]

I'm still not sure I buy the story that it was intentional. If they knew how it worked it would be easy to fix. I think they really just don't want to fix it - it is a 10 year old car way out of warranty, as far as they care it could be scrapped.

I mean, the first MSV70 work started in like 2004. Imagine going back and working on a 12 year old software project to debug it, that's also obsolete.. you probably wouldn't do it either.

[Three_thirty_I]

Originally Posted by Efthreeoh

All I can say is that when the car gives the "+1 QT" notification, just add in a quart of oil. I think even at 7 quarts, the oil sump has room for a slight overfill. Every time I've topped off at less than 1 quart, the oil level readings fluctuate from full to less than full. Every time I've topped off at the notification mark, the level remains at full for several thousands of miles. I can't stress enough to just follow the "+1 QT" procedure and the system responds without issues. It's designed to be topped off in 1-quart intervals, as that is what the owners manual says to do. Doing otherwise is just fighting the design and engineering of the car.

I know some knucklehead will come on and disagree (like Clifton) and make an argument, but I've done 21 oil changes to this date, which is probably more than most owners here and I'm about 400 miles shy of 300,000 miles. So by this time I think it's fair to say I'm quite familiar with how to maintain the N52.

Peace.

I haven't had to top up oil in years, partly due to not driving the car enough between services and there not being any drop in oil level, and I honestly think that the early oil consumption that I saw from the day I bought the car, it has been every improving - not sure how the previous "lady" owner drove the car, but anyway. I always topped up only when it showed the + 1 ltr (or + 1 QT) message, and never had problems at the time. It would just take a while to register the new level, but was then fine afterwards.

I know some have suggested that once the level gets to 25% above min to add half the amount (500 ml) so that the engine is always somewhere between 25% and 75% above min, but I also suspect that this may not be the best thing to do.