[javeci01]

Hello,

What is the oil change interval (specifically time not miles) for the CBS system? I would have sworn every time I have changed the oil and reset the system, it would reset for one years time. However, I went the dealership to get my oil changed and now it says 8/2023 which is essentially 2 years? Has anyone else come across this?

Thanks!

[RayLivingston]

"CBS system"??? What is that??

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Yeah mine says that too. Just change it every 12-15k miles or once a year. I'm unsure why it says two years.

[mapleleaf1773]

In sorry but never wait 12k plus miles to change your oil.

Thats how your upper end needs rebuilt amongst other things. Plus the filter operation breaks down way before that timeframe.

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Originally Posted by mapleleaf1773

In sorry but never wait 12k plus miles to change your oil.

Thats how your upper end needs rebuilt amongst other things. Plus the filter operation breaks down way before that timeframe.

I'm at 11.5 years and 132,000 miles with this interval. It's perfectly fine - BMW designed the engine and filter with this interval.

[RayLivingston]

Originally Posted by mapleleaf1773

In sorry but never wait 12k plus miles to change your oil.

Thats how your upper end needs rebuilt amongst other things. Plus the filter operation breaks down way before that timeframe.

Hmmm... Yet I've done oil changes entirely by the CBS for the life of both my E46 and E90, and both are absolutely pristine inside - not a hint of sludge anywhere, and both have excellent compression, (185-190PSI) dead even across all 6 cylinders. The E46 how has 240K miles on it, and the E90 has 140K miles on it.

[mapleleaf1773]

Well you guys rock. Regardless of said interval I'd never do that. You guys have "good luck"...

I agree to disagree

[ctuna]

There are already many long and heated debates on this
here.
Sorry the process of combustion and Oil Contamination
has not changed and maybe oils got a bit better but byproducts
of combustion are still the same and pollution controls make sure
that they have to be recycled through the Intake.
Hence Walnut Cleaning on the Turbo's

At the same time the recall Interval of the Car is set to once every two years on time
the Warranty book says change yearly.

[RayLivingston]

Originally Posted by mapleleaf1773

Well you guys rock. Regardless of said interval I'd never do that. You guys have "good luck"...

I agree to disagree

So your position is BMW designed the oil change interval to destroy their engines in short order? Why would they do that?

I worked for Ford and Chrysler, and I can tell you all maintenance intervals are designed to maximize life and minimize cost. NO manufacturer would publish a maintenance interval that would significantly shorten the life of the engine, or any other major component. There is one simple reason for this - that is exactly how you lose customers. I know lots of people with BMWs, ALL of them follow the CBS, and I am the ONLY one I know of who has had to do ANY significant internal work on their engine, and that was a head rebuild on my E46 at 195K miles, when a chunk of the #2 exhaust valve went missing. Can't blame that on oil change intervals. I rebuilt the head, and it's been fine since. In over 240K miles, that is the ONLY time that engine has been "open" further than removing the valve cover to replace the gasket. And when I opened it up, it was just like new inside, with absolutely no visible wear anywhere. Like most cars, most problems with BMWs tend to trace back to poor maintenance, not design or improper recommended maintenance intervals. It is NOT luck.

The CBS system calculates oil life based on actual running conditions. More cold starts, or more stop and go driving == more frequent oil changes. More highway driving == less frequent oil changes. The oil level sender senses not only oil level, but oil CONDITION, level of contamination. So it pretty much KNOWS what the oil condition is, it doesn't just guess, or use a canned one-size-fits-all schedule.

What evidence can you produce that following CBS will result in upper end damage, other than old wives tales?

[ctuna]

They designed the Maintenance plan to get the maximum benefit to them.
And I think this was mostly a marketing trend with Free or No Maintenance
being the reason.

If you have read any of problems across the models they screw up a lot
with basic design problems . The more expensive the car is the more outrageous
the problems .
For instance if the accessory belt breaks and get's sucked into the Engine
you need a new Engine . And a 10 dollar metal plate over the Intake seal could
have prevented this .
Timing Chain problems all over the place on the 4cylinder models.
5 series engine N63 battery must be replaced at every oil change.

CBS in 3 series stops working after 39 oil changes it's a down counter.

[lookalikehuuh]

Originally Posted by RayLivingston

So your position is BMW designed the oil change interval to destroy their engines in short order? Why would they do that?

I worked for Ford and Chrysler, and I can tell you all maintenance intervals are designed to maximize life and minimize cost. NO manufacturer would publish a maintenance interval that would significantly shorten the life of the engine, or any other major component.

Ummmm... have you seen how many shit plastic parts BMW built into these cars? Let's not forget electric fuel pumps that are all known failure points. Oh what about he "lifetime" transmission fluid that is anything but does this maximize the life of the transmission.

Be real, BMW doesn't give a shit about the car lasting 200k, they only need it to last the 50k that is covered by the their warranty, anything outside of that is not their problem whatsoever.

To further prove the point BMW shortened the service intervals significantly in the generations of vehicles that came after the E9x chassis went out of production. Even in vehicles that shared the exact same engine as the E9x engine, N55 for example.

Btw you should NEVER say that Chrysler has done anything to maximize reliability and minimize cost, they are literally the posted child of how not to build a vehicle. Chrysler vehicles have dominated bottom of the consumer report reliability reports for decades they are such shit vehicles that I am surprised that company is still in business... maybe our government tax dollars should have not bailed them out a decade ago and let them die the death they deserve.

[javeci01]

Thanks everyone. Sorry didn't mean to open a can of worms about the right oil change interval, I know this has been discussed in the forum at length. I have been changing at least once a year, I don't drive the car much.

My question was directed at if the car's computer always had the oil change interval as 2 years when reset (I thought it was 1 year and XX miles).

[RayLivingston]

No, the interval is neither a fixed time nor mileage. It is calculated, on-the-fly, based on actual miles driven, actual driving conditions, whether short trips, stop-and-go conditions or lots of highway miles. This lets it estimate the oil conditions. Under best possible conditions, it will come out to something like 15K miles/2 years, but will generally be less. Two different cars, with two different sets of driving conditions will give two different oil change intervals.

[ky0u]

Originally Posted by ctuna

For instance if the accessory belt breaks and get's sucked into the Engine
you need a new Engine . And a 10 dollar metal plate over the Intake seal could
have prevented this .

Stuff like this is the most hilariously frustrating thing about ownership and you see similar stuff throughout the car.

I don't have knowledge about oil chemistry or anything like that. But 12-15k interval for oil (particularly if you drive hard) seems to be tempting things a bit. And taking into account stuff like planned obsolecense and seeing how cars conveniently seem to have issues surface after warranty expires....

I've been doing mine every 6-7k. Plus with FCP euro, the changes are pretty much free. And even if they werent, and extra $50-60 once or twice a year is a fair price for some peace of mind imo.

Not to take anything away from those with high mileage cars that have stuck to the recommended interval. I do not have the miles on my car to even think of debating whether or not it's luck or proven.

[mapleleaf1773]

[QUOTE=RayLivingston;28025826]So your position is BMW designed the oil change interval to destroy their engines in short order? Why would they do that?/QUOTE]

I never that at all. I just said I'd never wait till 12k plus to change oil. That is for any vehicle I have owned in my life not just BMW. Don't care who has worked for who or anyones experiences. I'm not debating this at all. I am just giving my opinion that 12 THOUSAND plus miles is a ridiculous interval (in my opinion) Regardless of any company or person suggesting this.

So I agree to disagree, thats all. Do what you want brother

"Its your engine and parts". I just hope you have enough class to tell the next owner things like this. Let them make a decision based on "your" maintenance scheduling" regardless of what the owners manual says.

[mapleleaf1773]

Originally Posted by RayLivingston

No, the interval is neither a fixed time nor mileage. It is calculated, on-the-fly, based on actual miles driven, actual driving conditions, whether short trips, stop-and-go conditions or lots of highway miles. This lets it estimate the oil conditions. Under best possible conditions, it will come out to something like 15K miles/2 years, but will generally be less. Two different cars, with two different sets of driving conditions will give two different oil change intervals.

I agree with all of this except your calculated numbers. Alot of variables

[mapleleaf1773]

Originally Posted by javeci01

Thanks everyone. Sorry didn't mean to open a can of worms about the right oil change interval, I know this has been discussed in the forum at length. I have been changing at least once a year, I don't drive the car much.

My question was directed at if the car's computer always had the oil change interval as 2 years when reset (I thought it was 1 year and XX miles).

Your good man. Obviously other people have better answers than me. Sorry to go off subject. This is a forum to help others with car woes not to debate useless items. I apologize. I dont get hurt by such things, lol.

But you can go in and code the oil interval differently if you choose to do so (in INPA, Protools etc... - your favorite coding software). But it has to be done everytime as it is a hard reset.

[jdstrickland]

Originally Posted by RayLivingston

No, the interval is neither a fixed time nor mileage. It is calculated, on-the-fly, based on actual miles driven, actual driving conditions, whether short trips, stop-and-go conditions or lots of highway miles. This lets it estimate the oil conditions. Under best possible conditions, it will come out to something like 15K miles/2 years, but will generally be less. Two different cars, with two different sets of driving conditions will give two different oil change intervals.

I believe all of this to be true and correct, with a caveat.

When I bought my car I took it for a PPI, and the guy made a statement that causes me to think that the Baseline Setting from which the calculations you describe is an adjustable setting. Having said that, I see no point in being able to change the baseline. Given the heated discussion this topic invokes, maybe there is a concession to have the car report an oil change interval differently than the factory algorithm. Perhaps I misunderstand what his comment was, but given what I think I heard and the question that was asked here, I think that the change interval baseline can be changed. But, yes the factory feels very strongly that the specified oil can be run for 15,000 miles under whatever passes for optimum conditions, and the car will reduce this distance as it deems necessary based upon the parameters under which the car is being driven.

[RayLivingston]

And, FWIW, what I described comes from reading the BMW Factory training manuals, which are the documentation for the training all dealer mechanics must take. These manuals describe, in considerable detail, exactly how nearly every system on the car works. A family member is a BMW mechanic, and he let me borrow the whole stack of E90 manuals for a few weeks. LOTS of interesting information in there!

[Efthreeoh]

Originally Posted by RayLivingston

No, the interval is neither a fixed time nor mileage. It is calculated, on-the-fly, based on actual miles driven, actual driving conditions, whether short trips, stop-and-go conditions or lots of highway miles. This lets it estimate the oil conditions. Under best possible conditions, it will come out to something like 15K miles/2 years, but will generally be less. Two different cars, with two different sets of driving conditions will give two different oil change intervals.

You left out the oil quality sensor, which is part of the oil level sensor; it tracks the level of oil contamination (just up to 186,000 miles though). The CBS also tracks fuel consumption as part of the algorithm. And counts cold starts.

[javeci01]

Thanks everyone.

To add more context to my question, I signed up for the $199 BMW Ultimate Care Oil Services, which provides 3 years of prepaid oil changes based on the car's computer. Given I don't drive a lot I usually only have to change the oil once a year per the computer, but when I brought it for an oil change and they reset the computer, it now says 2 years, so thought it was strange it changed after I signed up for the pre-paid service...

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Originally Posted by javeci01

Thanks everyone.

To add more context to my question, I signed up for the $199 BMW Ultimate Care Oil Services, which provides 3 years of prepaid oil changes based on the car's computer. Given I don't drive a lot I usually only have to change the oil once a year per the computer, but when I brought it for an oil change and they reset the computer, it now says 2 years, so thought it was strange it changed after I signed up for the pre-paid service...

You can code it to be a lower value if you'd like, but they might notice that it doesn't reset to the "normal" amount.