[Clifton]

Originally Posted by Efthreeoh

Yeah, I agree, just like people who believe what BMW writes about Z cars made out of plastic.

I rember you being wrong in that thread too with multiple tantrums and all. But that was over a year ago, you really should learn to move on and stay on topic this time.

[Efthreeoh]

Originally Posted by Clifton

I rember you being wrong in that thread too with multiple tantrums and all. But that was over a year ago, you really should learn to move on and stay on topic this time.

I fondly remember the tantrums as yours; but your right I brought up the topic of kids and magic in this thread not you...

[Clifton]

Originally Posted by Efthreeoh

I fondly remember the tantrums as yours; but your right I brought up the topic of kids and magic in this thread not you...

If the tantrums were mine why did you get banned, not once, but twice?

How about staying on topic.....

[Efthreeoh]

So to uncover the magic and provide better understanding on the subject of the oil quality sensor. Fellow member Oulixes posted the below information three years ago, which is one of the best and detailed discussions on how the oil quality sensor works posted on the Forum. I will add to this information that BMWs engineers most likely anticipated owners may think the system should determine when the oil is changed merely by the improvement of the presence in oil additives once the oil quality is changed with fresh oil and therefore not reset the CBS indicator (or expect it to reset itself). However, the CBS oil life monitor also records and uses dynamic engine operating parameters in the algorithm that determines when the oil needs to be changed. These parameters are things like cold engine starts, rate of engine temperature rise, fuel consumption, miles driven, etc. It would make total sense that the oil life monitor system would be designed to not only look at the "improvement" of the oil condition by influence of adding a fresh quart of oil to the system (or even a complete oil change) because it is only one of the parameters measured by the system to determine the oil change interval and is used in conjunction with the other dynamic engine operating parameters mentioned above. In other words, as the CBS starts its countdown to the next oil change, it ignores the momentary improvement of the oil condition (by the influence of fresh oil) and only looks at the rate of dielectric change in the downward direction so as to not end up at very long OCIs without an oil filter change or increase other contaminations in the oil that are not measured by the sensor.

[ctuna]

Since the oils capacitance is effected by quality ?
Does that mean the oil level measurement become more inaccurate
with older oil? Also I have noticed some odd measurements when driving in really hot conditions which return to normal when the temperature does.

[Clifton]

Originally Posted by Efthreeoh

So to uncover the magic and provide better understanding on the subject of the oil quality sensor. Fellow member Oulixes posted the below information three years ago, which is one of the best and detailed discussions on how the oil quality sensor works posted on the Forum. I will add to this information that BMWs engineers most likely anticipated owners may think the system should determine when the oil is changed merely by the improvement of the presence in oil additives once the oil quality is changed with fresh oil and therefore not reset the CBS indicator (or expect it to reset itself). However, the CBS oil life monitor also records and uses dynamic engine operating parameters in the algorithm that determines when the oil needs to be changed. These parameters are things like cold engine starts, rate of engine temperature rise, fuel consumption, miles driven, etc. It would make total sense that the oil life monitor system would be designed to not only look at the "improvement" of the oil condition by influence of adding a fresh quart of oil to the system (or even a complete oil change) because it is only one of the parameters measured by the system to determine the oil change interval and is used in conjunction with the other dynamic engine operating parameters mentioned above. In other words, as the CBS starts its countdown to the next oil change, it ignores the momentary improvement of the oil condition (by the influence of fresh oil) and only looks at the rate of dielectric change in the downward direction so as to not end up at very long OCIs without an oil filter change or increase other contaminations in the oil that are not measured by the sensor.

I agree - I think what Oulixes provided was/is good information regarding the oil level sending unit. In the past, I've studied the BMW literature/diagrams on the subject and found it helpful as well.

It is key to point out though that even in the BMW docs available on-line, the "oil condition" component is a bit nebulous. Yes, one can follow along that some measurement is taking place as oil loses it's dielectric property and creates a contact between two diodes (measure of resistance?), but that's not really oil condition. That sounds like an extreme measurement - as in, the oil is failing and contains lots of metal.

As my post above pointed out, the so called "oil quality/condition" meter is clearly not sensitive to change. Seven quarts of fresh oil should have a dramatic affect on the OCI. Imagine that same concept with a fuel gauge where filling the tank would not raise the level to FULL or increase the vehicles reported range.

Also, Oulixes stated that oil quality requires the oil service to be reset for the algorithm to work properly. So how is unit really measuring the oils condition???

That tells me that "condition" is a broad term and in this case is more of a fail safe/catch all. For example in the event the engine is experiencing high wear due to the extended 15K oil change intervals and needs to trigger a recommended oil service.

If BMW's oil condition meter actually measured real oil condition (remaining additive package, silicon, water, fuel, TBN, metal particles by type) like the OP's oil analysis shows, then I would believe in magic.

[Efthreeoh]

Originally Posted by Clifton

I agree - I think what Oulixes provided was/is good information regarding the oil level sending unit. In the past, I've studied the BMW literature/diagrams on the subject and found it helpful as well.

It is key to point out though that even in the BMW docs available on-line, the "oil condition" component is a bit nebulous. Yes, one can follow along that some measurement is taking place as oil loses it's dielectric property and creates a contact between two diodes (measure of resistance?), but that's not really oil condition. That sounds like an extreme measurement - as in, the oil is failing and contains lots of metal.

As my post above pointed out, the so called "oil quality/condition" meter is clearly not sensitive to change. Seven quarts of fresh oil should have a dramatic affect on the OCI. Imagine that same concept with a fuel gauge where filling the tank would not raise the level to FULL or increase the vehicles reported range.

Also, Oulixes stated that oil quality requires the oil service to be reset for the algorithm to work properly. So how is unit really measuring the oils condition???

That tells me that "condition" is a broad term and in this case is more of a fail safe/catch all. For example in the event the engine is experiencing high wear due to the extended 15K oil change intervals and needs to trigger a recommended oil service.

If BMW's oil condition meter actually measured real oil condition (remaining additive package, silicon, water, fuel, TBN, metal particles by type) like the OP's oil analysis shows, then I would believe in magic.

I'll re-address my counterpoints to the points you made in your first post and again as you state above. But in summary, some of your contentions based off your observations could be valid if the measurement of the oil dielectric constant were the only data the CBS used to determine the oil change interval. Additionally, while is obvious that a complete chemistry lab cannot be packaged into the oil pan of a BMW engine, the use of an in-line oil quality monitor measuring the oil dielectric constant is a highly accurate analogous testing method to determine contamination and chemical change of the oil. It is a method used for decades in industrial applications, large machinery, and automobile engines.

The reason the oil service indicator needs to be reset is because it uses time and mileage inputs in conjunction with the oil quality sensor input. Since time and mileage only progress forward, once the oil is changed, the algorithm used by the CBS needs to begin a new event of monitoring time and mileage as part of its calculation of when to next change the oil. Further, the BMW CBS is designed to give the owner an estimated time and mileage of when the next oil change is due, so it needs to start a count from some point in time (and mileage). As I stated previously, and as you theorize that the oil quality sensor will detect changes in the dielectric constant of the oil when fresh oil is introduced into the oil sump, the oil dielectric measurement is not the single data input the CBS uses to determine oil quality, so the CBS does not solely rely on measurement of the oil's dielectric constant.

The oil quality sensor is sensitive to change; as I stated before, the CBS is designed to ignore sudden improvement in the oil's dielectric constant from the introduction of fresh oil because it would be unnecessarily difficult (or justified) to account for such minute changes in the oil dielectric constant and minutely adjust the estimated mileage interval (considering other environmentally-induced factors are involved in calculation OCI as well). This is one of the reasons why BMW recommends only adding full quarts of oil when the sump gets low on oil; 1 quart probably doesn’t change the dielectric constant much, but adding new oil at 1 quart quantities allows the system to better recognize the change. As I stated previously, the CBS uses other metrics in conjunction with the input from the oil quality sensor to determine oil quality such as time, mileage, cold engine starts (where most engine wear occurs), rise in engine temperature (i.e. we all know it is not good to apply full-throttle to a cold engine), fuel consumption (leads to estimating how much fuel can be possibly diluted in the oil over time), and other parameters, so solely relying on the oil quality sensor measurement of the oil’s dielectric constant change (and your subsequent expected automatic “reset” of the system from determination that 7 fresh quarts of oil are added to the engine sump), is not the most reliable method of starting a new countdown of the next OCI. Use of the other parameters to assist in the determination of oil quality is based on BMW's and other manufacturer's extensive lubrication testing of engine oil performance over the past decades.

To address your last point, which is the oil quality sensor can’t measure “real oil condition (remaining additive package, silicon, water, fuel, TBN, metal particles by type) like the OP's oil analysis shows”, I’ll plagiarize a well written article from Machinery Lubrication on The Dielectric Constant and Oil Analysis, written by A.A. Carey and A.J. Hayzen of Emerson Process Management. To quote excerpts:

The dielectric constant of a material is a measure of its ability to transmit electrical potential energy. In electrical systems such as capacitors, the effectiveness of dielectrics is measured by their ability to store energy. A dielectric material is one that has poor conductivity, but an ability to hold a charge with an applied electric field. The dielectric constant is a simple number that is the relative ratio of the speed of an electric field in a material compared to the speed of the electric field in a vacuum.

Comparison of the bulk dielectric constant of new and used oil can also give useful information in other areas of oil analysis. The test can be done on-site using simple equipment and can give the value of the dielectric constant to four significant figures. For example, if the user has a baseline measurement of the dielectric constant of the new oil, then a higher dielectric constant than usual from a used oil sample indicates either contamination, or a change in the chemistry of the oil… Comparison of the change in dielectric between new and used oil can also give important information on oil quality. Any increase in the bulk dielectric constant is undesirable and indicates the presence of some type of contaminant or a change in chemistry of the oil, such as oxidation. Other things that will change the dielectric constant of used oil include an increase in viscosity changes in acid number or base number and additive depletion… Because of the simplicity of the technique, online dielectric constant sensors are available which are capable of continuously monitoring oil quality in many applications.

The full article can be found here.

http://www.machinerylubrication.com/...t-oil-analysis

I hope this is "on Topic" enough for you.

[Clifton]

Originally Posted by Efthreeoh

I'll re-address my counterpoints to the points you made in your first post and again as you state above. But in summary, some of your contentions based off your observations could be valid if the measurement of the oil dielectric constant were the only data the CBS used to determine the oil change interval. Additionally, while is obvious that a complete chemistry lab cannot be packaged into the oil pan of a BMW engine, the use of an in-line oil quality monitor measuring the oil dielectric constant is a highly accurate analogous testing method to determine contamination and chemical change of the oil. It is a method used for decades in industrial applications, large machinery, and automobile engines.

The reason the oil service indicator needs to be reset is because it uses time and mileage inputs in conjunction with the oil quality sensor input. Since time and mileage only progress forward, once the oil is changed, the algorithm used by the CBS needs to begin a new event of monitoring time and mileage as part of its calculation of when to next change the oil. Further, the BMW CBS is designed to give the owner an estimated time and mileage of when the next oil change is due, so it needs to start a count from some point in time (and mileage). As I stated previously, and as you theorize that the oil quality sensor will detect changes in the dielectric constant of the oil when fresh oil is introduced into the oil sump, the oil dielectric measurement is not the single data input the CBS uses to determine oil quality, so the CBS does not solely rely on measurement of the oil's dielectric constant.

The oil quality sensor is sensitive to change; as I stated before, the CBS is designed to ignore sudden improvement in the oil's dielectric constant from the introduction of fresh oil because it would be unnecessarily difficult (or justified) to account for such minute changes in the oil dielectric constant and minutely adjust the estimated mileage interval (considering other environmentally-induced factors are involved in calculation OCI as well). This is one of the reasons why BMW recommends only adding full quarts of oil when the sump gets low on oil; 1 quart probably doesn’t change the dielectric constant much, but adding new oil at 1 quart quantities allows the system to better recognize the change. As I stated previously, the CBS uses other metrics in conjunction with the input from the oil quality sensor to determine oil quality such as time, mileage, cold engine starts (where most engine wear occurs), rise in engine temperature (i.e. we all know it is not good to apply full-throttle to a cold engine), fuel consumption (leads to estimating how much fuel can be possibly diluted in the oil over time), and other parameters, so solely relying on the oil quality sensor measurement of the oil’s dielectric constant change (and your subsequent expected automatic “reset” of the system from determination that 7 fresh quarts of oil are added to the engine sump), is not the most reliable method of starting a new countdown of the next OCI. Use of the other parameters to assist in the determination of oil quality is based on BMW's and other manufacturer's extensive lubrication testing of engine oil performance over the past decades.

To address your last point, which is the oil quality sensor can’t measure “real oil condition (remaining additive package, silicon, water, fuel, TBN, metal particles by type) like the OP's oil analysis shows”, I’ll plagiarize a well written article from Machinery Lubrication on The Dielectric Constant and Oil Analysis, written by A.A. Carey and A.J. Hayzen of Emerson Process Management. To quote excerpts:

The dielectric constant of a material is a measure of its ability to transmit electrical potential energy. In electrical systems such as capacitors, the effectiveness of dielectrics is measured by their ability to store energy. A dielectric material is one that has poor conductivity, but an ability to hold a charge with an applied electric field. The dielectric constant is a simple number that is the relative ratio of the speed of an electric field in a material compared to the speed of the electric field in a vacuum.

Comparison of the bulk dielectric constant of new and used oil can also give useful information in other areas of oil analysis. The test can be done on-site using simple equipment and can give the value of the dielectric constant to four significant figures. For example, if the user has a baseline measurement of the dielectric constant of the new oil, then a higher dielectric constant than usual from a used oil sample indicates either contamination, or a change in the chemistry of the oil… Comparison of the change in dielectric between new and used oil can also give important information on oil quality. Any increase in the bulk dielectric constant is undesirable and indicates the presence of some type of contaminant or a change in chemistry of the oil, such as oxidation. Other things that will change the dielectric constant of used oil include an increase in viscosity changes in acid number or base number and additive depletion… Because of the simplicity of the technique, online dielectric constant sensors are available which are capable of continuously monitoring oil quality in many applications.

The full article can be found here.

http://www.machinerylubrication.com/...t-oil-analysis

I hope this is "on Topic" enough for you.

So in summary - the oil quality (LOL) sensor is not really doing much if at all. I completely agree.

[Efthreeoh]

Originally Posted by Clifton

So in summary - the oil quality (LOL) sensor is not really doing much if at all. I completely agree.

So in summary, "LOL" is not a coherent reply, makes no counter point, nor any sense; and shows you argue just for argument sake.

[Clifton]

9:42 PM

Originally Posted by Efthreeoh

So in summary, you have no reply that makes any point, nor any sense.

9:49 PM

Originally Posted by Efthreeoh

So in summary, "LOL" is not a coherent reply, makes no counter point, nor any sense; and shows you argue just for argument sake.

Oooooh, your second edited retort, what is the word I'm looking for, meeeeeee-ow.

Regardless of the number of times the words "dielectric constant" can be used in a paragraph, your guesswork is just that and I'm sticking to what I've said from the beginning: It's NOT much of a quality sensor, if at all.

Not that it comes as a surprise, but assumptions about how the BMW CBS algorithms work is all just conjecture. Neither you nor I know what that software is doing without guessing, so any argument about how the oil quality sensor is being used is technically moot.

As my real life example above simply demonstrates, if oil condition is being captured, that information is being utilized much differently than what the term "oil condition" implies. And based on my example it appears that CBS is ignoring the positive impact that new oil has, i.e., increasing the mileage of the change interval. Therefore, to an owner/operator: It's NOT much of a quality sensor, if at all.

[F32Fleet]

Don't forget guys there are other maintenance items which must be addressed with prescribed mileage. Oil, air, and fuel filters. Not to mention BMW probably sets the Min/Max for the oil service.

[Efthreeoh]

Originally Posted by Clifton

9:42 PM



9:49 PM


Oooooh, your second edited retort, what is the word I'm looking for, meeeeeee-ow.

Regardless of the number of times the words "dielectric constant" can be used in a paragraph, your guesswork is just that and I'm sticking to what I've said from the beginning: It's NOT much of a quality sensor, if at all.

Not that it comes as a surprise, but assumptions about how the BMW CBS algorithms work is all just conjecture. Neither you nor I know what that software is doing without guessing, so any argument about how the oil quality sensor is being used is technically moot.

As my real life example above simply demonstrates, if oil condition is being captured, that information is being utilized much differently than what the term "oil condition" implies. And based on my example it appears that CBS is ignoring the positive impact that new oil has, i.e., increasing the mileage of the change interval. Therefore, to an owner/operator: It's NOT much of a quality sensor, if at all.

I'm taking her advice.

BTW, your whole existence on this Forum is a temper tantrum.

[Clifton]

8/21 11pm

Originally Posted by Efthreeoh

I'm taking her advice.

8/23 7am

Originally Posted by Efthreeoh

I'm taking her advice.

BTW, your whole existence on this Forum is a temper tantrum.

It's sweet knowing that you think about me so much that you are compelled by emotions to make edits to your own post 2 days later. Kind of sad....

[Efthreeoh]

Originally Posted by Clifton

8/21 11pm


8/23 7am


It's sweet knowing that you think about me so much that you are compelled by emotions to make edits to your own post 2 days later. Kind of sad....

Now now. Stay on topic son.

[Clifton]

Originally Posted by Efthreeoh

Now now. Stay on topic son.

Longing to be my father is a pretty creepy fantasy to announce publicly.

Another awkward moment brought to you by Efthreeoh...

[ska///235i]

[Efthreeoh]

Originally Posted by ska325xi

Yeah me too!

Not sure why Clifton is since he always

[NoTempoLimitN54]

Originally Posted by 2008_BMW_328xi

No additives were added, just 1/2 quart of make up oil after a very long trip, that's the only oil its burned, ever.

The oil got thicker as it's now a 5W40. Evaporation caused the thickening???

My OCI resets to 20k miles...yes, miles, not km.

I did a UOA on my N54 335i after 4250 mi on stock oil (BMW 5W-30). Wear metals were low, with only Iron (21) and Copper (14) exceeding 10 ppm.

Here's how my anti-wear additives tested:

122 Molybdenum
48 Boron
780 Phosphorous
930 Zinc

As for viscosity, I think this has to do with the Viscosity Improver additives. BMW 5W-30 is a Type III oil which means it's highly refined mineral oil base. Castrol won the legal right to call that "synthetic" in the U.S. (not allowed in Germany). I remember reading that for conventional oils, the VI makes the oil flow better at low temperatures. So I'm guessing here that as conventional multi-grade oil wears, it gets thicker. True synthetics are the opposite IIRC.

My oil read 10.58 CSt @ 100ºC after 4250 miles.

Here are some result from my E39 with M52TU engine:

Mobil 1 0W-40: 14.30 cSt @ 100ºC / 12,385 mi
Mobil 1 0W-40: 13.38 cSt @ 100ºC / 4,068 mi
Mobil 1 15W-50: 14.32 cSt @ 100ºC / 3,800 mi