Official S65 Bearing Specification/Clearance Wiki

[swamp2]

Originally Posted by BMRLVR

Well, you are speculating just as much as I am by saying there is no connection between less oil clearance and bearing wear.

I never said that. What I said is that I have not seen any conclusive data in this particular case, nor data for other vehicles. We can all easily abstract to the cases of way out of the norm too tight or too loose of a bearing clearance and both will be disastrous. So certainly there is a connection.

Originally Posted by BMRLVR

You have admitted that you have no formal assembly nor engineering experience when it comes to engines. I do, and even though I am not an engineer I have hundreds of hours of technicial training specific to engine systems, applied failure analysis, and not to mention hundreds of hours of lubricant training from Exxon/Mobil and Petro Canada and Shell.

Since I have all of this valid training not to mention thousands of hours of engine assembly under my belt, I'd appreciate it if you'd stop discounting everything I post, because quite frankly in my opinion all I see from you is quoting equations and theories from textbooks and online. I agree that your input is valuable, but you have to stop telling everyone how much smarter you are than they are. If both of us had to build an engine I am quite sure I could show you a thing or two, and if we had to engineer a part you could show me. Just give up that condescending tone you have with everyone.

Telling someone they are speculating or or wrong is not the same as condescending. I never made a claim that the widely varying backgrounds present on the forum in general and participating in this discussion aren't highly valuable. In fact I firmly believe just the opposite. However, if I began to lecture or correct you on some aspect of large diesel engine assembly, I'd clearly be out of my domain and although I could be correct, most likely I wouldn't be and very well might get schooled by you. However, when "engine builders" have and continue to make clearly and fundamentally incorrect statements about the math/engineering/physics aspects of this case, it becomes painfully obvious that they too can get outside of their domains of expertise quite quickly. Quoting a respected textbook or equation known to be pretty well exact and accepted is simply a way to engage in evidence based debate.

What would be particularly interesting to me, that you may be able to provide is some shred of data about clearance vs. wear or a comparison of the total maximum allowable range of clearance on other similar engines. Some here have claimed the information is more or less "all over", "easy to find" and just "look it up". I've made some attempts and have come up pretty empty handed. There are quite some differences one must account for in bearing design for diesel engines vs. gasoline. However, the fundamentals of hydrodynamic bearing lubrication are the same.

Originally Posted by BMRLVR

P.S.: Remember when you installed your BBK, you didn't even know enough to get the left and right calipers on the proper sides. You put the bleeder screws facing down at the lowest point in the caliper. How did you intend to get all of the air out? Not a small mistake for someone that knows everything!

I certainly claim the opposite, it is relatively inconsequential and certainly in the big picture. Funny thing is that the brakes bled and worked just fine. Obviously that FU was corrected before any hard track use. The flip side of this example is that I did extensive design, engineering, testing and development work for an entirely original and novel bicycle disc brake system. The product was brought to market and successfully sold in volume. One highlight of my engineering contributions to that system was a hollow ceramic piston and custom viton seal which radically reduced heat flow into the brake fluid. I guess the point is that everyone can and does make mistakes. My mistake here neither means I'm a terrible (personal/home) mechanic nor takes away from my various automotive related engineering accomplishments.

With that way too long winded response, let's get back on topic...

[tech2351]

Since the people working more closely with the bearing issue are posting within this thread, id like to cross post from another thread to get some feedback from my opinions and observations.

As an outsider looking in, and a new owner of an e90 m3, I would like to comment on the issue at hand after reading this thread in its entirety, and my first post...

Observations:

1. The bearing tolerance spec for the rod bearings, while slightly on the tight side per the .00075" - .001" recommendation, isn't really all that tight when compared to other high revving , race proven, engines. For example, (how dare I compare a honda to bmw, but sorry, ITR's and the like dont just spin rod bearings) Honda ITR motor, B18C5 uses .0013" to .0020" clearance on the rod bearings, and even .0009" to .0017" on mains, it rev's high rpm up to 8400rpm. This motor uses 5w-30........I can assure you, oil pressure and flow is no problem with those tight clearances @ 8400.. And the S2000 F20c engine however is using the 10w30 , is still a 30 weight oil, with tight clearances, and was designed before 5w-30's became more advanced in their shear stability.

Honda has designed some of first, and highest revving n/a engines , s2000 9,000 rpm, gsr 8200, ITR 8400, etc..They don't spin rod bearings like these engines, and use 5w-30 to 10w-30 for the s2k., so how much does all the hype over shear and proper viscosity when hot, really matter between a 60 and a 30 weight oil at high rpm and temperatures?

2. I think where BMW went wrong was trying to achieve a "balance" of race proven oil, and Long life intervals. Or even worse, money..The contractual agreement between castrol and BMW , pure speculation, but i digress..

I believe the choice to run 10w-60 is flawed due to viscosity of 10w-60 at cold starts. Sure 10-60 is great for track use, but how do we know that it is great for the s65? The only way we would know is to see what the oil pressure is at track oil temps, over 250degrees. I would opt to use the lowest weight oil possible to achieve around 80 or so psi which is plenty, @ 8000 rpm.

At high temperatures, you need a heavier weight oil to keep the viscosity up due to extreme heat. However, the bearing clearances as we know, are already fairly on the tight side, the restriction or "resistance" caused by the smaller tolerances, increases pressure to begin with, so does the s65 really need a 60 weight oil to achieve proper pressure and flow, (volume) through such small clearances at higher temperatures?

I believe that this engine, as a daily driver, could even use a 30 weight oil to achieve proper lubrication during high revs and 0w oil during cold starting.

It seems as if most of the rod bearing failures are from cylinders 6-8, per pictures that iv'e seen anyway. Those cylinders are furthest away from the oil pump, coupled with too heavy of an oil at cold start, and the possibility of people not letting the oil reach temperature before driving, could result in the outcomes we are seeing, overtime.

For everyday usage and occasional high rpm driving coupled with the clearances of this motor, and the anecdotal evidence we have with the 0w-40 results, could prove that lighter weight oil is the proper option for the s65.

Now if you plan on tracking the car all day, a heavier weight oil could be the option, BUT, what oil pressures are we achieving with 60 weight, at race temperatures? Is the oil pump constantly on it's relief or whatever means the s65 has to control oil pressure? only someone with a pressure gauge can tell us that....

Lastly, it would be nice to see what tolerances the GTR's and the like are running on their rods, coupled with their oil recommendations of 0w-40, if the tolerances are around the same as our s65's , then why 10w-60 weight? For pure shear tolerance? Is it correct that some 30-40 weight synthetics have just as good shear protection?

I feel as if the 0w-40 option is actually quite correct. I wouldn't go as far as 0w-20 of course...

So that's my opinion.. feel free to flame and correct. HAHAHAHA

[thekurgan]

Originally Posted by tech2351

Since the people working more closely with the bearing issue are posting within this thread, id like to cross post from another thread to get some feedback from my opinions and observations.

As an outsider looking in, and a new owner of an e90 m3, I would like to comment on the issue at hand after reading this thread in its entirety, and my first post...

Observations:

1. The bearing tolerance spec for the rod bearings, while slightly on the tight side per the .00075" - .001" recommendation, isn't really all that tight when compared to other high revving , race proven, engines. For example, (how dare I compare a honda to bmw, but sorry, ITR's and the like dont just spin rod bearings) Honda ITR motor, B18C5 uses .0013" to .0020" clearance on the rod bearings, and even .0009" to .0017" on mains, it rev's high rpm up to 8400rpm. This motor uses 5w-30........I can assure you, oil pressure and flow is no problem with those tight clearances @ 8400.. And the S2000 F20c engine however is using the 10w30 , is still a 30 weight oil, with tight clearances, and was designed before 5w-30's became more advanced in their shear stability.

Honda has designed some of first, and highest revving n/a engines , s2000 9,000 rpm, gsr 8200, ITR 8400, etc..They don't spin rod bearings like these engines, and use 5w-30 to 10w-30 for the s2k., so how much does all the hype over shear and proper viscosity when hot, really matter between a 60 and a 30 weight oil at high rpm and temperatures?

2. I think where BMW went wrong was trying to achieve a "balance" of race proven oil, and Long life intervals. Or even worse, money..The contractual agreement between castrol and BMW , pure speculation, but i digress..

I believe the choice to run 10w-60 is flawed due to viscosity of 10w-60 at cold starts. Sure 10-60 is great for track use, but how do we know that it is great for the s65? The only way we would know is to see what the oil pressure is at track oil temps, over 250degrees. I would opt to use the lowest weight oil possible to achieve around 80 or so psi which is plenty, @ 8000 rpm.

At high temperatures, you need a heavier weight oil to keep the viscosity up due to extreme heat. However, the bearing clearances as we know, are already fairly on the tight side, the restriction or "resistance" caused by the smaller tolerances, increases pressure to begin with, so does the s65 really need a 60 weight oil to achieve proper pressure and flow, (volume) through such small clearances at higher temperatures?

I believe that this engine, as a daily driver, could even use a 30 weight oil to achieve proper lubrication during high revs and 0w oil during cold starting.

It seems as if most of the rod bearing failures are from cylinders 6-8, per pictures that iv'e seen anyway. Those cylinders are furthest away from the oil pump, coupled with too heavy of an oil at cold start, and the possibility of people not letting the oil reach temperature before driving, could result in the outcomes we are seeing, overtime.

For everyday usage and occasional high rpm driving coupled with the clearances of this motor, and the anecdotal evidence we have with the 0w-40 results, could prove that lighter weight oil is the proper option for the s65.

Now if you plan on tracking the car all day, a heavier weight oil could be the option, BUT, what oil pressures are we achieving with 60 weight, at race temperatures? Is the oil pump constantly on it's relief or whatever means the s65 has to control oil pressure? only someone with a pressure gauge can tell us that....

Lastly, it would be nice to see what tolerances the GTR's and the like are running on their rods, coupled with their oil recommendations of 0w-40, if the tolerances are around the same as our s65's , then why 10w-60 weight? For pure shear tolerance? Is it correct that some 30-40 weight synthetics have just as good shear protection?

I feel as if the 0w-40 option is actually quite correct. I wouldn't go as far as 0w-20 of course...

So that's my opinion.. feel free to flame and correct. HAHAHAHA

You've not written one word that wasn't already mentioned here for the past few years. Welcome to the board.

[nthretourNAFTW]

This is the most inconclusive and useless thread in the history of this forum.
When this thread was started like everyone else i read it but also made significant contributions in the first 8 pages.( I've taken a turn in the wheel of forum flame wars since, I am no longer posting under that account). The problem with the thread itself is its inceptor was ill equipped with very insufficient analytical skills and no mechanical design engineering insights and rigor. He then made things worse by piling and listing data without clear structure or synthesis, all from lack of real engineering analytical skills.

I now completely disagree with the "flawed bearings tolerance" hypothesis. Yes some bearings have spun, and looked abnormally worn and engine have self destructed, but all these are symptoms and consequences not root cause.

When someone dies of a stroke, it didn't start with the myocardium heart muscle being the issue , it's just one of the last chain of event before the failure, and not where it started to go awry.

If you take an athlete who learns a bad technique, he will develop a problem eventually and finally injury.
chain of reactions from root to eventual failed part can be quite long.

I think the problem with the s65 (and s85) is inconsistent oil supply. Not the oil itself, not the bearing clearance, but the oil delivery system. Consider the following video, it is not an M car or even a recent model, but a bmw V8 engine and what this man found in his oil pan was absolutely shocking: 8 screws and 1 nut that came loose from the oil pump. V8 engines are known for vibrations. To be fair this man's car had a "low oil pressure" warning code come up on the dash but only at idle speeds, his case was extreme. For a high revving engine a much smaller or very short pressure drop could have slow but significant consequences without triggering a fault.

The S65 has one oil pressure switch/sensor, it doesn't give the actual pressure inside the engine block head. So the pressure are inferred by design which makes many assumptions about the whole oil supply system being tight and operational. What about if several screws are loose somewhere in either oil pumps (without leak) so that oil pressure does not distribute as expected by design ? Although completely unrelated there have been cases of loose screw in the rear differential on this car, which make it at least a possibility. I wouldn't expect anyone to find screws in the oil pan but I suspect some screws or lugs coming loose and staying on.

The oil switch part # has been changed twice by bmw. The last change being 04/2013. and previously 07/2012. Were they on to something about oil pressure ?

04 OIL PRESSURE SWITCH M12X1,5 1 07/2012 12617620512 ENDED, +core
04 OIL PRESSURE SWITCH M12X1,5 1 04/2013 12612367061 ENDED
04 OIL PRESSURE SWITCH M12X1,5 1 12618611273

Has anyone checked both oil pumps and their mounting hardware torque in a failed engine ?

[8600RPM]

Finally a realistic hypothesis.

[regular guy]

Originally Posted by nthretourNAFTW

This is the most inconclusive and useless thread in the history of this forum.
When this thread was started like everyone else i read it but also made significant contributions in the first 8 pages.( I've taken a turn in the wheel of forum flame wars since, I am no longer posting under that account).

Yes, I knew you were sunsweet for quite some time. No real secret there. But why did you go off the rails with me? Was it because I disagreed with you when you suggested (as sunsweet) if a poll were started to ask how many people suffered from RB failure, then we would all know the world-wide failure rates within six weeks? You remember, I disagreed with you because it assumed all S65 owners were on the forum (which is clearly false). And somebody did create such a poll a few days later, and if I remember correctly, it only got about 20 people who responded in six weeks. I'm wondering if that disagreement is what turned you from being very helpful to nothing but personal attacks for no apparent reason. So it's no coincidence to me that the spreadsheet you came up with under your latest screen name has the same flaw of sunsweet in assuming all S65 owners are on the forum.

The problem with the thread itself is its inceptor was ill equipped with very insufficient analytical skills and no mechanical design engineering insights and rigor. He then made things worse by piling and listing data without clear structure or synthesis, all from lack of real engineering analytical skills.

That's a pretty serious charge, and I didn't even see an attempt to offer any proof.

I now completely disagree with the "flawed bearings tolerance" hypothesis. Yes some bearings have spun, and looked abnormally worn and engine have self destructed, but all these are symptoms and consequences not root cause.

That's fine...and your proof is where? If you're going to make these serious allegations, then I think all of us would expect you to make sure you don't fall into the same failure -- lack of analytical skills, lack of evidence, etc. I'm still looking for some proof what you say, and wondering why none was presented.

When someone dies of a stroke, it didn't start with the myocardium heart muscle being the issue , it's just one of the last chain of event before the failure, and not where it started to go awry.

If you take an athlete who learns a bad technique, he will develop a problem eventually and finally injury.
chain of reactions from root to eventual failed part can be quite long.

I think you're going off the rails here.

I think the problem with the s65 (and s85) is inconsistent oil supply. Not the oil itself, not the bearing clearance, but the oil delivery system. Consider the following video, it is not an M car or even a recent model, but a bmw V8 engine and what this man found in his oil pan was absolutely shocking: 8 screws and 1 nut that came loose from the oil pump. V8 engines are known for vibrations. To be fair this man's car had a "low oil pressure" warning code come up on the dash but only at idle speeds, his case was extreme. For a high revving engine a much smaller or very short pressure drop could have slow but significant consequences without triggering a fault.

Where's the proof? I'm not saying it's not true, but if you're going to make these allegations, then you have to meet a higher threshold and at least live up to your own standards of proof, evidence, and analytical skills. I'm not seeing any of that here.

The S65 has one oil pressure switch/sensor, it doesn't give the actual pressure inside the engine block head. So the pressure are inferred by design which makes many assumptions about the whole oil supply system being tight and operational. What about if several screws are loose somewhere in either oil pumps (without leak) so that oil pressure does not distribute as expected by design ? Although completely unrelated there have been cases of loose screw in the rear differential on this car, which make it at least a possibility. I wouldn't expect anyone to find screws in the oil pan but I suspect some screws or lugs coming loose and staying on.

It sounds like you don't know how the S65 oil system works. You might want to study up on that. Plenty of people have run real oil pressure gauges, including data logging versions. I think their results easily contradict your theory that came with no evidence or proof.

The oil switch part # has been changed twice by bmw. The last change being 04/2013. and previously 07/2012. Were they on to something about oil pressure ?

04 OIL PRESSURE SWITCH M12X1,5 1 07/2012 12617620512 ENDED, +core
04 OIL PRESSURE SWITCH M12X1,5 1 04/2013 12612367061 ENDED
04 OIL PRESSURE SWITCH M12X1,5 1 12618611273

Speaking of analytical skills, do you want me to tell you how easy it is to check these parts to see how they differ from each other? If this is your theory, then you really need to come up with some evidence, and testing each of these sensors is incredibly easy to do. Check back in when you've got the results.

Has anyone checked both oil pumps and their mounting hardware torque in a failed engine ?

Yes, at least twice. What would you like to know about them?

[pbonsalb]

Originally Posted by nthretourNAFTW

This is the most inconclusive and useless thread in the history of this forum.
When this thread was started like everyone else i read it but also made significant contributions in the first 8 pages.( I've taken a turn in the wheel of forum flame wars since, I am no longer posting under that account). The problem with the thread itself is its inceptor was ill equipped with very insufficient analytical skills and no mechanical design engineering insights and rigor. He then made things worse by piling and listing data without clear structure or synthesis, all from lack of real engineering analytical skills.

I now completely disagree with the "flawed bearings tolerance" hypothesis. Yes some bearings have spun, and looked abnormally worn and engine have self destructed, but all these are symptoms and consequences not root cause.

When someone dies of a stroke, it didn't start with the myocardium heart muscle being the issue , it's just one of the last chain of event before the failure, and not where it started to go awry.

If you take an athlete who learns a bad technique, he will develop a problem eventually and finally injury.
chain of reactions from root to eventual failed part can be quite long.

I think the problem with the s65 (and s85) is inconsistent oil supply. Not the oil itself, not the bearing clearance, but the oil delivery system. Consider the following video, it is not an M car or even a recent model, but a bmw V8 engine and what this man found in his oil pan was absolutely shocking: 8 screws and 1 nut that came loose from the oil pump. V8 engines are known for vibrations. To be fair this man's car had a "low oil pressure" warning code come up on the dash but only at idle speeds, his case was extreme. For a high revving engine a much smaller or very short pressure drop could have slow but significant consequences without triggering a fault.

The S65 has one oil pressure switch/sensor, it doesn't give the actual pressure inside the engine block head. So the pressure are inferred by design which makes many assumptions about the whole oil supply system being tight and operational. What about if several screws are loose somewhere in either oil pumps (without leak) so that oil pressure does not distribute as expected by design ? Although completely unrelated there have been cases of loose screw in the rear differential on this car, which make it at least a possibility. I wouldn't expect anyone to find screws in the oil pan but I suspect some screws or lugs coming loose and staying on.

The oil switch part # has been changed twice by bmw. The last change being 04/2013. and previously 07/2012. Were they on to something about oil pressure ?

04 OIL PRESSURE SWITCH M12X1,5 1 07/2012 12617620512 ENDED, +core
04 OIL PRESSURE SWITCH M12X1,5 1 04/2013 12612367061 ENDED
04 OIL PRESSURE SWITCH M12X1,5 1 12618611273

Has anyone checked both oil pumps and their mounting hardware torque in a failed engine ?

There were no bolts laying in the bottom of my oil pan when I pulled it to do a preventative maintenance rod bearing change. There were no bolts loose anywhere that I noticed. So your hypothesis doesn't work for me. As for BMW part number changes, you find them for many parts on the car and it does not mean the original part was defective. Also, if your hypothesis on the oil pressure switch was correct, we would have failures in the early cars with the early switches but not in the later cars with the "improved" switches. Unfortunately, that is not the case.

[Longboarder]

Sorry have only read some of the 118 pages. Frankly haven't worried about rod bearings on my car but perhaps that's naive since I've now passed 30k miles and love it so much (can't find another car out there I'd rather daily drive) that I've decided to buy it out of lease.

Some of what I have gathered is that a lot of the wear could be attributable to start up. So could the factory cold start feature with initial higher/jumpy rpm's be the cause of more start up wear? I ask because since 900 miles my car has been supercharged / decatted and cold start was so loud I've used the ESS cold start delete tune for essentially the life of the car. Despite the fact I go wot to 8,600 rpm daily and used to race this car frequently, I've been religious about waiting until oil temp is at normal range before going over 2,500 rpm's - car stays in s2 automatic until desired oil temp reached.

For the same reason I have an umbrella insurance coverage, I may do rod bearings just to be sure. But I don't want to if I don't have to. My cold start theory isn't even a theory...just more of a question which maybe a combination of bad luck (tighter than average clearance) plus more start up wear from cold start plus hard initial drive off may be a cause.

Cheers.

[whats77inaname]

Originally Posted by Longboarder

Sorry have only read some of the 118 pages. Frankly haven't worried about rod bearings on my car but perhaps that's naive since I've now passed 30k miles and love it so much (can't find another car out there I'd rather daily drive) that I've decided to buy it out of lease.
Cheers.

That says a lot considering what else you have in the garage. Glad you'll be with us for awhile

[Longboarder]

Originally Posted by whats77inaname

That says a lot considering what else you have in the garage. Glad you'll be with us for awhile

If I could only have one car, it would be this one. Not even kidding. Best all around car ever IMHO.

[kawasaki00]

Originally Posted by nthretourNAFTW

This is the most inconclusive and useless thread in the history of this forum.
When this thread was started like everyone else i read it but also made significant contributions in the first 8 pages.( I've taken a turn in the wheel of forum flame wars since, I am no longer posting under that account). The problem with the thread itself is its inceptor was ill equipped with very insufficient analytical skills and no mechanical design engineering insights and rigor. He then made things worse by piling and listing data without clear structure or synthesis, all from lack of real engineering analytical skills.

I now completely disagree with the "flawed bearings tolerance" hypothesis. Yes some bearings have spun, and looked abnormally worn and engine have self destructed, but all these are symptoms and consequences not root cause.

When someone dies of a stroke, it didn't start with the myocardium heart muscle being the issue , it's just one of the last chain of event before the failure, and not where it started to go awry.

If you take an athlete who learns a bad technique, he will develop a problem eventually and finally injury.
chain of reactions from root to eventual failed part can be quite long.

I think the problem with the s65 (and s85) is inconsistent oil supply. Not the oil itself, not the bearing clearance, but the oil delivery system. Consider the following video, it is not an M car or even a recent model, but a bmw V8 engine and what this man found in his oil pan was absolutely shocking: 8 screws and 1 nut that came loose from the oil pump. V8 engines are known for vibrations. To be fair this man's car had a "low oil pressure" warning code come up on the dash but only at idle speeds, his case was extreme. For a high revving engine a much smaller or very short pressure drop could have slow but significant consequences without triggering a fault.

The S65 has one oil pressure switch/sensor, it doesn't give the actual pressure inside the engine block head. So the pressure are inferred by design which makes many assumptions about the whole oil supply system being tight and operational. What about if several screws are loose somewhere in either oil pumps (without leak) so that oil pressure does not distribute as expected by design ? Although completely unrelated there have been cases of loose screw in the rear differential on this car, which make it at least a possibility. I wouldn't expect anyone to find screws in the oil pan but I suspect some screws or lugs coming loose and staying on.

The oil switch part # has been changed twice by bmw. The last change being 04/2013. and previously 07/2012. Were they on to something about oil pressure ?

[whats77inaname]

Just going to leave this here....

[BMRLVR]

Originally Posted by nthretourNAFTW

This is the most inconclusive and useless thread in the history of this forum.
When this thread was started like everyone else i read it but also made significant contributions in the first 8 pages.( I've taken a turn in the wheel of forum flame wars since, I am no longer posting under that account). The problem with the thread itself is its inceptor was ill equipped with very insufficient analytical skills and no mechanical design engineering insights and rigor. He then made things worse by piling and listing data without clear structure or synthesis, all from lack of real engineering analytical skills.

I now completely disagree with the "flawed bearings tolerance" hypothesis. Yes some bearings have spun, and looked abnormally worn and engine have self destructed, but all these are symptoms and consequences not root cause.

When someone dies of a stroke, it didn't start with the myocardium heart muscle being the issue , it's just one of the last chain of event before the failure, and not where it started to go awry.

If you take an athlete who learns a bad technique, he will develop a problem eventually and finally injury.
chain of reactions from root to eventual failed part can be quite long.

I think the problem with the s65 (and s85) is inconsistent oil supply. Not the oil itself, not the bearing clearance, but the oil delivery system. Consider the following video, it is not an M car or even a recent model, but a bmw V8 engine and what this man found in his oil pan was absolutely shocking: 8 screws and 1 nut that came loose from the oil pump. V8 engines are known for vibrations. To be fair this man's car had a "low oil pressure" warning code come up on the dash but only at idle speeds, his case was extreme. For a high revving engine a much smaller or very short pressure drop could have slow but significant consequences without triggering a fault.

The S65 has one oil pressure switch/sensor, it doesn't give the actual pressure inside the engine block head. So the pressure are inferred by design which makes many assumptions about the whole oil supply system being tight and operational. What about if several screws are loose somewhere in either oil pumps (without leak) so that oil pressure does not distribute as expected by design ? Although completely unrelated there have been cases of loose screw in the rear differential on this car, which make it at least a possibility. I wouldn't expect anyone to find screws in the oil pan but I suspect some screws or lugs coming loose and staying on.

The oil switch part # has been changed twice by bmw. The last change being 04/2013. and previously 07/2012. Were they on to something about oil pressure ?

04 OIL PRESSURE SWITCH M12X1,5 1 07/2012 12617620512 ENDED, +core
04 OIL PRESSURE SWITCH M12X1,5 1 04/2013 12612367061 ENDED
04 OIL PRESSURE SWITCH M12X1,5 1 12618611273

Has anyone checked both oil pumps and their mounting hardware torque in a failed engine ?

Do some reading about hydraulics and you will see how what you are saying here makes no sense at all!

[IIAp3x]

I think BMW came off the rails when they manufactured the first S65...

RB refresh every 50k miles is my solution... If the bearings will last that long!

[Stainless 45]

Have there been any non-supercharged engines that have blown up while running 0W-40 that we know of? Is this the best temporary fix until the new bearings become available?

[SenorFunkyPants]

Originally Posted by Stainless 45

Have there been any non-supercharged engines that have blown up while running 0W-40 that we know of?

At least 2

Originally Posted by Stainless 45

Is this the best temporary fix until the new bearings become available?

If you live in a cool climate and are easy on the car then it might help.
If you life in a warm climate and are hard on your car then its probably worse.

[BMRLVR]

Originally Posted by SenorFunkyPants

At least 2



If you live in a cool climate and are easy on the car then it might help.
If you life in a warm climate and are hard on your car then its probably worse.

This is nonsense! The 0W40 Mobil has more than adequate film strength for an NA S65 in nearly any climate, It really is not that impressive of an engine with regards to output anymore. The climate is mostly going to effect the cold start viscosity, where the 0W40 will always be superior. The climate doesn't matter at all as long as the engine oil temperature on your gauge is in normal operating range.

FYI, the new Dodge 6.2L SC engine in the hellcat that makes 707HP is another engine that a 0W40 is factory fill in and that the Mobil 1 0W40 is approved for! I think that with the likes of the Porsche GT3 and 911Turbo, Nissan GTR, Mercedes for all AMG models and the many other cars that run the Mobil 0W40 as factory recommended oil proves that the Mobil 0W40 is not going to have a problem in the S65.

[SenorFunkyPants]

Castrol 100% synthetic 10W60 will have a greater film strength than Mobil 1 0W40 (not 100% synthetic in the USA) at the same engine temp. In hotter climates under hard usage oil temps will be above normal, a situation where less film strength is usually undesirable.
What other manufacturers recommend for their cars is irrelevant.

[IIAp3x]

Originally Posted by SenorFunkyPants

Castrol 100% synthetic 10W60 will have a greater film strength than Mobil 1 0W40 (not 100% synthetic in the USA) at the same engine temp. In hotter climates under hard usage oil temps will be above normal, a situation where less film strength is usually undesirable.
What other manufacturers recommend for their cars is irrelevant.

Yeah I agree, It's hot here in Florida and already in the 90's... I'll be sticking with 10w 60...

[regular guy]

Originally Posted by SenorFunkyPants

Castrol 100% synthetic 10W60 will have a greater film strength than Mobil 1 0W40 (not 100% synthetic in the USA) at the same engine temp. In hotter climates under hard usage oil temps will be above normal, a situation where less film strength is usually undesirable.
What other manufacturers recommend for their cars is irrelevant.

I noticed you gave up on octane as the cause of death and now it's all about oil film strength? How does that now explain all the stock engine failures on stock oil in hot climates?

[regular guy]

Originally Posted by IIAp3x

Yeah I agree, It's hot here in Florida and already in the 90's... I'll be sticking with 10w 60...

Didn't you already have one engine failure? Was that on 10w60 or something else?

[BMRLVR]

Originally Posted by SenorFunkyPants

Castrol 100% synthetic 10W60 will have a greater film strength than Mobil 1 0W40 (not 100% synthetic in the USA) at the same engine temp. In hotter climates under hard usage oil temps will be above normal, a situation where less film strength is usually undesirable.
What other manufacturers recommend for their cars is irrelevant.

Higher film strength is fine but not if it comes at the cost of lack of flow at start-up and until the engine is warm.

The 0W40 Mobil1 is indeed full synthetic and is blended entirely out of Group IV/PAO base stocks.

It has been shown quite frequently on UOA's that the Castrol shears down to a light 50 or even a heavy 40 weight oil in short order, meaning it has no more film strength than the Mobil anyhow. Don't get me wrong, the Castrol 10W60 is a great oil, just not for a daily driven car with tight bearing clearances.