[RPM90]

Originally Posted by rfx45

Same engineers that has made BMWs reliability so notorious?

BMW's are quite reliable mechanically.
Generally, BMW's get dinged on those surveys due to the overly complicated electronics they implement, as BMW likes to be at the forefront of technology not behind it. If you're an innovator there is always a risk with being an early adopter.
However, over time BMW does respond to the problems and makes serious attempts to fix the issues.

When it comes to mechanical things, and especially engines, BMW's are very reliable.
The HPFP issue did hurt BMW, but they found an answer, offered a solution, and gave extended warranty on the affected part.
That's pretty good imo. Toyota buried their sludging problem pretty well.
Think back, when was the last time you heard of BMW engines having problems with extended mileage use? When have you heard of engine problems resulting from a too long oil change interval?

For that matter, think about most all car makers. Modern engine building has come a LONG way from the days of leaky gaskets, and faulty rings where blue smoke from the tailpipe was a common feature in nearly all engines. I remember when all GM small blocks were expected to start burning oil by 100K miles, it was given. If you had one of those engines and it didn't smoke it was considered exceptional. Now, if your engine burns oil by 100K miles, that is the exception and not the norm.
Those were the oil smokey days of 3000-5000 mile oil changes. It sure didn't help those cars. That was due to engine manufacturing of that era. It's a different manufacturing world now. As well, oil technology is not what it was back then. Even non synthetics are better than they were, and synthetics are amazing at what they can now offer. We have higher powered engines and better MPG these days. Oil tech is part of that success.

[m6pwr]

Originally Posted by Elk

m6pwr, you are overstating your "data." At best, we have a large range of mileage at which one can reasonably change the oil.

There is no "correct" answer and no one is going to be "right."

If all engineers and manufacturers agreed as to the specific mileage to change an oil fill we would all know by now.

We can all agree that if the oil is older than a year, change it. Let's leave it at that.

Elk, I agree with you, man. I'm just presenting a viewpoint (and data, as meager as you think it is) - - one that is different than what some seem to think and advocate (that oem's oci's are crap and that you have to shorten them if you want your car to last). I'm not on a crusade to assert that everyone MUST adhere to BMW's oci. And I'm responding to a question. The questioner, and others who have viewed this thread, can make up their own mind. Let them decide if the data is overstated, and how they want to proceed. I agree that people can change their oil whenever they want and live happily ever after.

# # # Finis # # #

[rfx45]

Originally Posted by RPM90

Think back, when was the last time you heard of BMW engines having problems with extended mileage use? When have you heard of engine problems resulting from a too long oil change interval?

Look a page back?

Originally Posted by zhp43867

... look up 335i carbon buildup, or one of the many threads where higher mileage 335s are running like crap due to the issue. Also search "Direct Injection Carbon Buildup", you'll find hours of reading material. Here's the tip of the iceberg. High quality fuel and better oil than BMW supplies coupled with more frequent oil change intervals should help prevent this from happening:

http://www.e90post.com/forums/showthread.php?p=10395959

http://www.e90post.com/forums/showthread.php?t=447516

http://forums.bimmerforums.com/forum....php?t=1669210

Either way, I think you missed the joke in my post. The quote I replied to stated engineers spent hundreds, thousands, millions of hours into designing and testing these cars as if it never has problems, ever. I mean Ferrari engineers labored hundreds, thousands of hours into the 458 but thing still catches on fire.

[Elk]

Originally Posted by RPM90

Your visual inspection will mean nothing, unless you have special eyes that can see different spectrums by which to judge an oil condition.

If you believe that one should change oil when they simply "feel like it", then that as unsubstantiated as you believe BMW's recommendation is, even more so.

You are reading way too much in my little off-hand comment and, if all of this is directed at me it is misdirected.

[Elk]

Originally Posted by m6pwr

Elk, I agree with you, man. I'm just presenting a viewpoint (and data, as meager as you think it is) - - one that is different than what some seem to think and advocate (that oem's oci's are crap and that you have to shorten them if you want your car to last).

Very fair, and I enjoyed taking a look at your references.

It is fascinating how complex the technology is. Each study looks into one characteristic (as is appropriate), but none appear to address the overall functional question in which we are interested.

Perhaps there will be a study of medium displacement turbocharged direct injection engines.

Then again, probably not.

[n55x3]

Originally Posted by RPM90

I remember when all GM small blocks were expected to start burning oil by 100K miles, it was given. If you had one of those engines and it didn't smoke it was considered exceptional. Now, if your engine burns oil by 100K miles, that is the exception and not the norm.
Those were the oil smokey days of 3000-5000 mile oil changes.

Man I miss those days too. Now BMW and many other car manufacturers will say that burning a quart of oil in 3-5,000 miles is the norm.

[RPM90]

Originally Posted by Elk

You are reading way too much in my little off-hand comment and, if all of this is directed at me it is misdirected.

Not all directed at you, no.
The main intent is to give a different point of view to viewpoints such as yours.

The visual inspection is a poor way by which to judge oil condition.
I didn't overstate it at all. Thinking you can judge your oil condition by looking at, is bad advice.
I'd counter that you overstated your ability.

[RPM90]

Originally Posted by n55x3

Man I miss those days too. Now BMW and many other car manufacturers will say that burning a quart of oil in 3-5,000 miles is the norm.

I've head some customers with excessive oil usage get the response that a quart every few thousand miles is "normal".
Luckily, most BMW and other brands don't tend to use that much oil.
Also, turbo's tend to use more oil than NA engines.

I can accept 1 quart every 5000-7000 miles, but not under 5K miles.
But not much you can do when the manufacturer says it's "normal". You'll have a fight on your hands.

[RPM90]

Originally Posted by rfx45

Look a page back?

Can you please clarify your comment?

My comment is not about isolated problems that can happen in any engine and brand. It's about the "whole" of the brand and series of engines.
Is there any fact or even perception that BMW engines do not last beyond 100K miles? Is there public knowledge or talk that BMW engines are of bad quality, and that it's due to long oil change intervals?

I haven't seen or read that those things are true, even since the BMW full synthetic change over in around 1999.

[geko29]

Originally Posted by zhp43867

Nothing will happen if you stretch a 7,500 mile oil change to 8,000 miles a few times, but stretch (or even follow) the 15,000 mile interval a couple thousand miles regularly, keep your car for 100,000 miles, and let me know how it turns out.

Ok, I will. With the exception of one half-interval change to swap the factory fill at 7500 miles, I've exclusively changed the oil on my E46 exactly when the OBC tells me to, which turns out to be around 18,000 miles. At the change closest to 70k (forget the exact mileage), I sent the old oil out for analysis. The lab said everything was in spec, and they told me to KEEP USING IT. But alas, it had already been changed.

Now I've got 102k. Last fall I had the valve cover and the VANOS unit off to replace the seals, and I was expecting some serious sludge on the valvetrain and the inside of the cover. Nope. Both looked absolutely brand new, with a thin coat of golden amber-colored oil on everything. And again, this was at an OCI, so this oil was 18k old, and had only been changed 5 times in the vehicle's lifetime.

When I replace it with an F30 in a year or two, I have absolutely no qualms about following the recommended interval. And my E46 is in such good shape after doing so, I'm actually thinking about keeping it rather than trading it in.

[jrob]

Ugh, oil thread #1 of probably 2,000 more to come...

[bcl0328]

Originally Posted by m6pwr

There was a recent rant (maybe on this forum - - can’t remember) about the lack of a dipstick on some of the latest BMW engines. Actually, you should be happy. That is an indication that the motor is equipped with a neat device designed by Bosch called an oil condition monitor. It constantly measures oil level and the dielectric properties of the oil. As the oil (very, very slowly) ages, picks up wear metals, acids, fuel dilution, and oxidizes, the conductivity or dielectric properties of the oil changes. That’s where all that field testing comes in. BMW can correlate the electrical values measured at any one time to the general condition of the oil and adjust the oil change interval if the oil is in danger of becoming unserviceable. Bosch’s latest oil condition monitor even has a little transducer that bounces sound waves off the oil to measure changes in viscosity. What more do you want?

any more info on this sensor?

[howiegu]

Originally Posted by m6pwr

3000 mile oil changes went out with ducktail haircuts and penny loafers. Where have you been for the last half century?

Read the owner's manual and follow the oil change interval prescribed by the CBS (condition based service) computer shown in the dash. Earlier oil changes are wasteful and unecessary.

I've been told by a very experienced euro-based lubricants engineer (Doug Hillary) that BMW does very extensive field testing on each of its models to establish effective and safe maintenance and lubrication schedules. Doug currently works for Mobil, but has worked also for Castrol and in collaboration with BMW specifically on the development of the TWS oil for M cars. According to Doug, BMW uses two independent field testing outfits and he knows personally some of the engineers there. These guys know what the hell they're doing - - more so than anyone on this or any of the other BMW forums (and that includes me, for sure) when it comes to lubrication.

Shortening the factory specified oil change intervals achieves nothing with regard to the longevity/durability of the engine, other than conveying that elusive "peace of mind", and this includes the practice of dumping the factory fill at 1500 mi to wash out all those nasty wear metals (even if BMW says it’s not necessary on your car - - after all what does BMW know – they only make the engines). The practice of gearheads dumping the factory fill at 1500 mi on a new car is a holdover from the days of push rods, carburetors, and bias ply tires.

There is even some recent data/testing (done by Ford and Conoco Philips) that indicates too frequent oil changes may actually be counterproductive. They did tests (published in an SAE paper) that showed that what they called aged oil, or oil thats been in use for awhile, sets up and actually does a better job of lubricating, particularly in antiwear, (up to its condemnation point) than green, fresh oil. So more frequent oil changes may actually increase wear. Heresy! There was a similar study done (I wished now I had bookmarked it) specifically with regard to the antiwear add zddp, that showed fresh oil would dissolve and remove the tribological antiwear layer laid down by the old oil before it would form its own layer. Hard to believe. With respect to the direct injected turbo motors (like the N54/N55) Hillary has even said that he has seen what he calls very reliable data that indicates shortening the oil change interval "negatively affects" the formation of deposits - - the fresh oil just feeds more deposits before it stabilizes.

There was a recent rant (maybe on this forum - - can’t remember) about the lack of a dipstick on some of the latest BMW engines. Actually, you should be happy. That is an indication that the motor is equipped with a neat device designed by Bosch called an oil condition monitor. It constantly measures oil level and the dielectric properties of the oil. As the oil (very, very slowly) ages, picks up wear metals, acids, fuel dilution, and oxidizes, the conductivity or dielectric properties of the oil changes. That’s where all that field testing comes in. BMW can correlate the electrical values measured at any one time to the general condition of the oil and adjust the oil change interval if the oil is in danger of becoming unserviceable. Bosch’s latest oil condition monitor even has a little transducer that bounces sound waves off the oil to measure changes in viscosity. What more do you want?

In spite of all this, we doubt BMW. We love the engineering that goes into the car but somewhere in our reptilian brain some atavism, some primordial fear, tells us the engineers can’t be trusted, that if we want the car to last we must halve the oil change interval to 7500 mi or 5000 mi or whatever.

I’d like to challenge anyone to post a link to a contemporary, scientific study by a reputable source that shows shortening the mfrs recommended oil change interval will increase the longevity and durability of the engine. And I don’t mean Mike Miller’s Old School Maintenance Schedule. I mean a study reported by the Society of Automotive Engineers, or the American Society of Mechanical Engineers, or the Society of Tribologists and Lubricants Engineers - - or similar.

And if you want to impress future buyers when you sell the car, show them UOA (used oil analysis) reports from a reputable ISO certified lab like Polaris (not Blackstone - - they don't do a good job on fuel dilution) showing that the oil you changed according to BMW's schedule was rockin good, and with the BMW it so well engineered that you don't have to spend $$$ doing oil changes at 5k, 7k or whatever.

Well put!
But some people still wear Members Only jacket

[howiegu]

Originally Posted by bcl0328

any more info on this sensor?

I think the last issue of Car and Driver or Roundel (can't remember which) had a good article on those two sensors.