My Latest Oil Report

You guys might remember my previous oil report from blackstone...

I just hit the 13k mile mark and here is my new report. I think this pretty much confirms that BMW was using a low-zinc break-in oil. What does silicon in the oil have to do with an air filter? I love this car and want to keep it forever. As a result I think I am going to keep with their recommended oil change interval.

Thoughts?

Notes from the report:

This oil was in place longer than the first sample, but wear improved pretty dramatically. This is a good sign that the engine is making its way through the wear-in process. Silicon is also washing out of the system, so we think the air filter is getting the job done. Low insolubles points to good oil filtration. Iron and copper will probably look even better next time. The TBN was a decent 2.6 with anything less than 1.0 being to low for extend use. No fuel or other harmful contaminants were present. Stay around 7,000 miles for now until iron drops a little more. Nice.

I interpert silicon as dirt hence the air filter comment. Initially I've heard it might minor leftovers from casting (hence higher reading on factory fill). Nothing to worry about IMO.

Question: What brand of oil did you use for this sample, and what did you re-fill with?

Originally Posted by BMWTurboDzl

Question: What brand of oil did you use for this sample, and what did you re-fill with?

I got the oil changed at the dealer, both times. At around 10k miles I was a quart low, so I went to the dealer for a top off. Not so funny story, dude tried to top off with oil for a gasoline engine. "I didn't know they made diesel sedans". Good thing I checked.

Thanks for sharing the oil analysis data.

Your first change was 5470 miles, correct ekay? My own car is just a little below that point now. I was considering doing a "customer pay" change, but since Blackstone confirmed the initial oil is some kind of special "break in" (or otherwise kinda exotic) maybe I might just wait until the one year point comes up and have BMW just do the complimentary "one year no matter how many miles" change...in other words, leave the first oil in for the full interval/or to one year point.

Please tell me what the letters "TBN" stand for?

Interesting how Blackstone commented that your initial oil "had a lot less zinc in it than usual." So yes it does appear to be a special oil. By the way, I have the exact same year/model 335 as the OP. Pretty good chance my sump has the same (initial-first) oil as he, I'd surmise.

Thanks again for the info!

rr-der

PS-- Yes, I have also needed a quart of "top off" oil to keep the level at the
top of the dipstick-- and used the specified Castrol CF (diesel approved) product.
That's what will go in at the first change, too.

"Please tell me what the letters "TBN" stand for?"

Total Base Number = TBN

Interestingly they (Blackstone) also does a TAN (Total Acid Number) test but they don't do it for vehicles. I wonder if you can special order that?

The general rule of thumb is that the oil is ready to be changed when TBN (moves downward) meets TAN (moves upward). There's a UOA out there on a X5d which had factory fill analyzed at normal OCI (ie, ~11k miles) and the TAN reading was @ around 4 while the TBN was @ around 1.

I changed out my factory fill at 6,500 miles.

My $.02

Originally Posted by BMWTurboDzl

"Please tell me what the letters "TBN" stand for?"

Total Base Number = TBN

Interestingly they (Blackstone) also does a TAN (Total Acid Number) test but they don't do it for vehicles. I wonder if you can special order that?

The general rule of thumb is that the oil is ready to be changed when TBN (moves downward) meets TAN (moves upward). There's a UOA out there on a X5d which had factory fill analyzed at normal OCI (ie, ~11k miles) and the TAN reading was @ around 4 while the TBN was @ around 1.

I changed out my factory fill at 6,500 miles.

My $.02

Silicon can also be present in the oil's additive package when new.

Zinc is also present as it helps the oil hold up to higher pressure, i.e. between moving parts such as bearings and crankshafts.

TBN should be a non-issue since you are running on ULSD. TBN is the additive used to help neutralize the acid forming products of combustion that blow by the piston rings.

In large marine diesels burning HFO, sometimes with Sulphur as high as 3% or even higher, TBN is raised to up to 55. As time goes the additive is depleted and TBN will drop until it reaches an equilibrium point or plateau. This plateau should be reached before 50%of the additive is depleted, or say a TBN of 27.5. If it drops below 50% you need to refresh or change the oil with the higher TBN.

When a diesel engine is burning ULSD, TBN is no longer an issue, there is no more acid forming sulphur to neutralize.

15ppm vs 30,000ppm Sulphur.

TAN is what you should be concerend with I think.

Originally Posted by Flyingman

Silicon can also be present in the oil's additive package when new.

Zinc is also present as it helps the oil hold up to higher pressure, i.e. between moving parts such as bearings and crankshafts.

TBN should be a non-issue since you are running on ULSD. TBN is the additive used to help neutralize the acid forming products of combustion that blow by the piston rings.

In large marine diesels burning HFO, sometimes with Sulphur as high as 3% or even higher, TBN is raised to up to 55. As time goes the additive is depleted and TBN will drop until it reaches an equilibrium point or plateau. This plateau should be reached before 50%of the additive is depleted, or say a TBN of 27.5. If it drops below 50% you need to refresh or change the oil with the higher TBN.

When a diesel engine is burning ULSD, TBN is no longer an issue, there is no more acid forming sulphur to neutralize.

15ppm vs 30,000ppm Sulphur.

TAN is what you should be concerend with I think.

TBN of 55? Well I guess those guys aren't running low-SAPS oils.

Originally Posted by Flyingman

Zinc is also present as it helps the oil hold up to higher pressure, i.e. between moving parts such as bearings and crankshafts.

Interesting.


I though the Zinc was for protection when the localized oil pressure was momentarily too low, allowing metal-to-metal contact, e.g., lots of zinc in gear oils because of lower oil pressure, not higher oil pressure, but of little importance in bearings and crankshafts since there is no metal-to-metal contact under operating conditions. From what I have read over the years, zinc phosphate had no effect on the plain bearings used for crankshafts, but has more to do with piston ring and cylinder wear at the top and bottom of the piston stroke when the rings reverse direction and momentarily reach zero velocity, unlike a plain bearing.

http://www.epi-eng.com/piston_engine...e_bearings.htm

The "Extreme Pressure" tag typically attached to zinc is not talking about the oil pressure, but the pressure between metal-to-metal contact, when the oil film itself might fail.

Originally Posted by Flyingman

Silicon can also be present in the oil's additive package when new.

Zinc is also present as it helps the oil hold up to higher pressure, i.e. between moving parts such as bearings and crankshafts.

TBN should be a non-issue since you are running on ULSD. TBN is the additive used to help neutralize the acid forming products of combustion that blow by the piston rings.

In large marine diesels burning HFO, sometimes with Sulphur as high as 3% or even higher, TBN is raised to up to 55. As time goes the additive is depleted and TBN will drop until it reaches an equilibrium point or plateau. This plateau should be reached before 50%of the additive is depleted, or say a TBN of 27.5. If it drops below 50% you need to refresh or change the oil with the higher TBN.

When a diesel engine is burning ULSD, TBN is no longer an issue, there is no more acid forming sulphur to neutralize.

15ppm vs 30,000ppm Sulphur.

TAN is what you should be concerend with I think.

Meh. Even with ULSD, there is some production of acids. I did an engine oil and filter replacement at 1200 miles, and the TBN was at 6.8. The next oil analysis showed a TBN result of 4.8. If there was no production of acids, TBN should not have dropped 2 whole points.

TAN measures sample acidity. TAN is usually measured when analyzing transmission or differential oil due to the general absence of acid reduction additives in the transmission/differential oil.

The interesting measures that no one has commented on yet are the OP's sample viscosity results. Those were within the range for each test, which is good.

Originally Posted by anE934fun

The interesting measures that no one has commented on yet are the OP's sample viscosity results. Those were within the range for each test, which is good.

The pessimist(sp) in me says "I would expect nothing less" due to the short OCI. If that UOA was for 10k miles OCI then I'd say that's somethin'.

Based upon only my own personal limited experience with the 335d, it has consumed Zero lube oil. This means no make up has been added, so no refreshing. Which in itself is an amazing feat for today's modern diesel engines. I recall having to add a quart of oil about every 1-2k miles, betwen leaks and combustion!

So, that means there is only dilution and pollution of the oil, meaning it can only get worse as time and miles go by. The filter, if it is doing it's job, will keep particulates under control, because that is all it does. It can not remove acid or other diluted contaminants.

The additive package of the oil has to then handle the rest, which is water (condensation), and products of combustion which forms acids and sludge. Sludge could be retained by the oil filter, and maybe some amount of water.

In the end it is obviously clear by the 15k oil/filter change interval that BMW has extensive faith in their design to warrant this.

The oil analysis I have seen thus far does not confer that one needs to run out and change the lube oil every 5k miles. If it gives you piece of mind, great. I deem it completely unecessary.

Unless you drive in really dirty, dusty conditions, like West Texas or the dessert.

Originally Posted by Flyingman

In the end it is obviously clear by the 15k oil/filter change interval that BMW has extensive faith in their design to warrant this.

Well, it certainly does show that they have extensive faith that it will not cause problems during the warranty period.

FWIW, my X35d asked for, and got, an oil change at 9,300 miles, not 15,000. I commented upon it when I took it in for the change, and the service manager said that while he had never seen a gasoline BMW ask for an oil change that soon, it was not uncommon for the diesel BMW's to ask around 10,000 miles.

Originally Posted by Penguin

Well, it certainly does show that they have extensive faith that it will not cause problems during the warranty period.

FWIW, my X35d asked for, and got, an oil change at 9,300 miles, not 15,000. I commented upon it when I took it in for the change, and the service manager said that while he had never seen a gasoline BMW ask for an oil change that soon, it was not uncommon for the diesel BMW's to ask around 10,000 miles.

But isn't this just a computer driven algorithm that looks at how you drive the vehicle vs any actual measurement of lube oil quality?

We all know that the OEM's tell you to change your oil more frequently when operating in dusty conditions, stop and go traffic, towing, etc...

The car telling you to change the oil prior to the 15k is purely it trying to anticipate oil condition based on operational input such as miles driven, how har you drove, how fast, perhaps also tempertaures.

It would be great if anyone here knew more specifics about how the BMW calculates the engine service interval. I recall reading something about it in my Z-3 manual some years ago.

In the end, if your oil viscosity is within range, the additive package still charged, and the oil filter is keeping particulates out of circulation, you should be good to go. And if your diesel engine is not burning oil it is most likely not seeing much blowby either, as the two go hand in hand. Again, my hats off to the engineers.

Originally Posted by Flyingman

But isn't this just a computer driven algorithm that looks at how you drive the vehicle vs any actual measurement of lube oil quality?

We all know that the OEM's tell you to change your oil more frequently when operating in dusty conditions, stop and go traffic, towing, etc...

The car telling you to change the oil prior to the 15k is purely it trying to anticipate oil condition based on operational input such as miles driven, how har you drove, how fast, perhaps also tempertaures.

It would be great if anyone here knew more specifics about how the BMW calculates the engine service interval. I recall reading something about it in my Z-3 manual some years ago.

In the end, if your oil viscosity is within range, the additive package still charged, and the oil filter is keeping particulates out of circulation, you should be good to go. And if your diesel engine is not burning oil it is most likely not seeing much blowby either, as the two go hand in hand. Again, my hats off to the engineers.

I don't believe so. I changed out the factory fill at 6,500 miles, and my service indicator, which is now counting down with some regularity, states I have ~3,300 miles before my next change. Basically what this means is that the CBS will likely indicate I'll required an oil change @`12,500 miles which is within the same mileage for those who've never changed their factory fill.



Go figure.

+1
I'm in the same boat, changed oil at around 4k and I'm do at about 11k anyhow at 1 year anniversary.

Originally Posted by Flyingman

But isn't this just a computer driven algorithm that looks at how you drive the vehicle vs any actual measurement of lube oil quality?

It it is primarily driven by a computer algorithm; however, the oil level sensors also has something called an oil quality sensor built into it (BMW refers to it as a QLT, Quality, Level, Temperature, sensor). I believe it measure the permittivity, and possible conductivity, of the oil to provide an indication of oil quality. I do not know how, or to what extent, this sensor info is integrated into the oil change interval algorithm.

I did a "Break-in" oil change at 2000mi, estimating that I would change it about every 7000mi thereafter. At just over 9000mi, the vehicle indicated it was several hundred mi away from needing an oil change. I had it changed (as part of maintenance program). My SA said he was seeing diesels every 8500-10,000 mi due to the onboard computer requesting it. I was planning on a 7000 mi interval anyway (which is about what I do on my 5er, and the diesel operates at higher temperatures and pressures), but it is good to see the computer agree.

I'm not sure exactly how the computer recognizes that it needs an oil change. I would think that in addition to oil level sensor there is an oil quality sensor which at least checks conductivity (as the oil degrades I understand it gets more acidic and thus conductivity rises). It is not a simple mileage count like on other makes (e.g., toyota).

As an aside, has anyone seen the new ford super duty trucks? I saw a review on autoblog and noticed that they put the DEF input right next to the fuel input.

http://www.autoblog.com/photos/2011-...drive/#2778910

Seems like that approach makes it more convenient to refill than on the x5/335d.

[QUOTE=kestrel;5387705]I did a "Break-in" oil change at 2000mi, estimating that I would change it about every 7000mi thereafter. At just over 9000mi, the vehicle indicated it was several hundred mi away from needing an oil change. I had it changed (as part of maintenance program). My SA said he was seeing diesels every 8500-10,000 mi due to the onboard computer requesting it. I was planning on a 7000 mi interval anyway (which is about what I do on my 5er, and the diesel operates at higher temperatures and pressures), but it is good to see the computer agree.

I'm not sure exactly how the computer recognizes that it needs an oil change. I would think that in addition to oil level sensor there is an oil quality sensor which at least checks conductivity (as the oil degrades I understand it gets more acidic and thus conductivity rises). It is not a simple mileage count like on other makes (e.g., toyota).

As an aside, has anyone seen the new ford super duty trucks? I saw a review on autoblog and noticed that they put the DEF input right next to the fuel input.

http://www.autoblog.com/photos/2011-...drive/#2778910

Kestrel,

Did you reset your service interval when you did the oil change? If not the computer has no idea you did change the oil so is still running from zero miles.

We need to get some input on what drives the service interval, but I doubt it will be the oil level or some other more sophisticated oil sensor or oil analysis. I beleive it will just be how hard you drive the "D" in regards to engine rpm, miles, acceleration, and perhaps temperatures (of what I don't know). Acidity should not actually increase since the additive is in there to neutralize it. What you look for is how much excess additive (TBN) is still in there to react with the acid forming products of combustion. That is why typically you don't want the TBN to drop lower than 50% of new oil. Once you deplete the TBN then the acids will be able to attack engine parts.

Oil level most likely will only active your SES or Check Engine light, i.e. an idiot light.

As for the DEF, I think BMW did this as an after thought since they weren't originally making these cars for the US Market, no DEF in the rest of the world.

The Ford was made for the US Market from the get go.

I stand corrected! See info below from a user's site

Some vehicle manufacturers estimate oil by using mathematical algorithms. The oil monitor keeps track of hours of engine operation, temperature, distance traveled and so on to estimate how much oil life is left. When a certain point is reached, the oil service reminder light comes on.

BMW uses an “adaptive” strategy to compute estimated oil life based on how much fuel the vehicle has consumed (which BMW says is more accurate than tracking the number of miles driven and hours of engine *operation). The CBS system also considers input from an oil quality sensor in the bottom of the oil pan. The oil quality sensor measures the electrical conductivity of the oil. As the additives in the oil wear out, the *resistance of the fluid changes.



The maximum service interval on late-model BMWs with this system is 25,000 km (15,500 miles, which the driver information display rounds up to read 16,000 miles). As the CBS system tracks fuel usage, it deducts mileage in 1,000-mile chunks from the remaining oil life. When there is an estimated 1,250 miles of oil life left, or if the oil quality sensor indicates a change is due sooner, the service reminder light comes on, and the oil status indicator changes color from green to yellow. Keep in mind that the 15,500-mile oil change *interval is based on using BMW’s High Performance 5W-30 synthetic oil, not ordinary oil. Also, most of these engines hold 7, 8 or 9 quarts of oil, depending on their crankcase capacity.

It isn’t clear whether BMW takes into consideration wear factors that accumulate with normal driving. A 15,500-mile oil change interval may be okay for a low-mileage engine with no piston ring or cylinder wear, but what about an engine with 100,000 or 150,000 miles on the odometer? Such long oil change intervals with a high-mileage engine that has more blowby and wear than a new engine may be asking for trouble.

[QUOTE=Flyingman;5388845]

Originally Posted by kestrel

Acidity should not actually increase since the additive is in there to neutralize it. What you look for is how much excess additive (TBN) is still in there to react with the acid forming products of combustion. That is why typically you don't want the TBN to drop lower than 50% of new oil. Once you deplete the TBN then the acids will be able to attack engine parts.

.

Figured you'd like to see this. Here is the UOA I spoke about earlier with the high TAN reading. Again I'm not sure how applicable it is in engines.

http://www.bobistheoilguy.com/forums...71#Post1876571

Originally Posted by Flyingman

IThe CBS system also considers input from an oil quality sensor in the bottom of the oil pan. The oil quality sensor measures the electrical conductivity of the oil. As the additives in the oil wear out, the *resistance of the fluid changes.

Actually, the sensor BMW uses measures permittivity via changes in the effective capacitance, not resistance.


While I am certain of the capacitance, having read it in BMW service documents, I am not 100% sure of their sensor source, but I believe it is a version of Continental's QLT Sensor:

(Page 83 of this catalog)
http://www.conti-online.com/generator/www/de/en/continental/automotive/general/contact_services/downloads/passenger_cars/powertrian/common/pow_powertrain_products_pdf_en.pdf

For those that are interested, here is an excellent, if slightly dated, article on the use of oil quality sensors in determining oil change intervals:

http://www.machinerylubrication.com/...filter-sensors

Originally Posted by Penguin

For those that are interested, here is an excellent, if slightly dated, article on the use of oil quality sensors in determining oil change intervals:

http://www.machinerylubrication.com/...filter-sensors

Ver cool. I'm assuming it's a pre-ULSD article.

Originally Posted by BMWTurboDzl

Ver cool. I'm assuming it's a pre-ULSD article.

Yeah, I think it is around 2004.