BMW M5 Forum and M6 Forums banner

41 - 47 of 47 Posts

·
Registered
Joined
·
410 Posts
@flacoramos
Thanks for the multiple statements on my reading abilities and comprehension. I've been a member on M3forum , e90post, bimmerfest and others for 8 years, I was in the market for an E92 long before I ever considered and E60. The people on those forums are far more knowledgeable. It is strange how I'm only slammed on this forum. Thanks for telling me to read those forums, I'm sure you somehow knew that I hadn't. Unclear why you would even say such statements.

I don't see anybody claiming film thickness has been measured. Read again perhaps?
Didn't you say this this?

As a side note, Troy's recommendation of using a hotter thermostat AND thinner 5w50 oil results in a two-fold decrease in oil film when hot.
Yes you didn't say film thickness, so perhaps explain what you meant by a two-fold decrease in oil film, if you weren't talking about film thickness.

Seems you don't know it's not just one BE failure but three. Robert (BE owner) is the first one to have shown pics of those engines (installer error). Have you read that too?
So you clearly have the most knowledge of anyone on the number of BE bearing failures, that's wonderful. I brought up what I said since you clearly omitted such knowledge in the prior post, once again talking about zero wear, but then conveniently not disclosing to the audience that you in fact knew of 3 failures! Unclear why one would do something like that.

But forget about oil and look into increased clearance bearings. The few examples that have used BE bearings and been disassembled have shown practically zero wear regardless of what oil you use.


Please show where BMW approves 5w50. If you refer to the infamous 2013 or so TSB then that's a unique way of interpreting a poorly worded document. That TSB has long been superseded and newtis currently (and has always showed afaik) 10W60 as the only approved oil except 5w30 during break-in. And even then BMW imposed a RPM limitation while using 5w30. There's a fresh link to the current newtis oil table in the tech service sticky
I attached the PDF which references BMW's approved oils for the "US market". These were LL-01 oils, which I incorrectly referenced as LL-04. This is indeed an old document (2008) now that I look at it, but it is age appropriate for our cars since BMW recognized engines were FAILING left and right. It says:

"If Castrol High Performance Synthetic Oil is not available and you need to add oil between oil changes, only use synthetic oils with the following specifications for M vehicles:
Viscosity – preferred SAE 10W-60
Alternative – SAE 10W-40, SAE 5W-50 or SAE 10W-50
Use only oils with an API rating of SJ/CF, SK/CF or higher.

Perhaps it is indeed poorly worded. There is a big emissions compliance aspect of Engine Oil and their additives, but I think few of us give a sh*t about that.

I also noticed that older versions of the BMW Specified Oils matrix do show the S85 having an X in the LL-04 column. BMW seems to have removed that "X" in the later version. I don't think they really bother with engines that were designed 15 years ago. See other attachment.

Regardless of the charts, the thing that really matters is the actual viscosity at low temps since oil flow on cold start is what critical. Seems like you disagreement whether a cause of the wear we see in S65 and S85 engines suffer is related to oil starvation. There is wide agreement that the failure mode is indeed due to wear from oil starvation, this includes Robert Collins. Others (including myself) have talked about this issue before, you no doubt have also read those threads. For people that have to start up their car in freezing temperatures, it is critical to have a low viscosity oil to mitigate the effects of oil starvation and the inability of the oil sump pickup tube to suck up an oil which is too thick. Excessively viscosus oil (thicker oil) also heats up slower (it also loses heat slower too). This thicker oil also harder to sheer when cold which results in the more internal resistance of the engine upon startup. Clearly there is a trade off for those who are running 250-280 degree oil temps despite the fact that it may be 10 degrees ambient temperature when they start the car. All those endurance racers in Alberta must have a hell of a time figuring out what oil to put in their M5...

I actually don't have the original Mahle Clevite Whitepaper. Please upload it for us, since you clearly have studied it in depth.
 

Attachments

·
Registered
Joined
·
410 Posts
So it stands to reason that it's better to idle the S85 engine till it reaches the optimal operational temp, regardless of using 10w60 or 0w40 oil, for the sake of RB longevity. Before putting any load on it, i.e. driving. Since I live in Santa Monica, CA, and 10 deg C (50 F) is the coldest it gets, the thicker 10w60 might be a better choice. BTW, this and other threads use acronyms which are not obvious, rather perplexing, to some like myself. For example, "clevite PDF on bearing wear", "BE bearing swap", "ACL bearings", "LL-04 matrix", "newtis oil table", etc. are terms not familiar to me. It'd be good to have a page on this Board where these are defined, and anybody using them make sure that they are. If not, comes up with a definition. Good idea? Thx
I love your username, you should know everything...

clevite PDF on bearing wear: Clevite (Mahle Clevite) is one of the largest original equipment bearing manufacturers in the world they make bearings for almost everyone. They had some of their R&D guys write a white paper on optimal bearing clearances for high performance engine applications (read: race engines)

BE bearing swap: Some very knowledgeable engine designers and builders formed a company named BE bearings. The redesigned the connecting rod bearings with different clearances and had Mahle Clevite make these. They are known as BE bearings

ACL bearings: Another manufacturer based in Australia that has also made different connecting rod bearings for the S65 and S85. They are a fraction of the cost of BE's and are available in 2 different sizes.

LL-04 matrix: This refers to BMW's periodically updated recommended oil specifications. LL-04 is just one of the specs, there is a LL-01 LL-02, etc. As emissions requirements change, and new engines are designed, there are different oil requirements. This matters more for warranty compliance. I don't think anyone with a S65 or S85 has BMW warranty any longer.

newtis: This is a site that hosts content from BMW's official technical document database. Don't assume that BMW approves of this being hosted like this, but they certainly do profit from the fact that having this knowledge out there helps keeps their POS cars on the road and pads their wallet from price gouging us schmucks who repair these unreliable POS. Markups on Porsche parts is worse, but they aren't selling parts like solenoids for 100x their cost, and their stuff doesn't have as many mechanical and electrical failures.
 

·
Moderator
Joined
·
1,949 Posts
The matrix you uploaded show the BMW recommendation has been the same from day one: 5W30 during break-in (1200mi/2k km) and 10W60 after that. Note (3) is clear about this. The owners manual has had the same verbiage allowing different oil viscosity when topping off. Again that's been there since day one. The TSB is not the one I'm referring to but is similar. Some people interpret page 2 as to say any LL-01 being ok.

As you pointed out oil viscosity is critical when starting in freezing temperatures. As stated before BMW recommendation for 10W60 is down to 0F-ish. BMW's recommendation for 10Wxx is in line with at least two other car manufacturers so what's special about bmw or TWS? I ran TWS during two Chicago winters and my daily-driver M5 didn't explode. AFAIK bearing failures don't exclusively occur in cold climates either. Lots of cars were sold in CA and TX and failures happened there as well. There's no evidence that I'm aware of showing cold viscosity being the problem.

Last I checked race engines extract every last tenth of HP so use of thinner oils is obvious. If they need to pre-heat oil so be it. Needs are different. What's the point of comparing what race teams use to a street-driven car? Completely different goals here.

The BE engine failures have been shown to be due to installer error. I've mentioned them in the past but are irrelevant here as BE had nothing to do with them. What's the point of accusing me of 'conveniently' hiding that info? Stop playing the victim please.

Of course each one will use whatever one desires. Just keep facts straight. I've switched to 5w50 in search of better mileage (mentioned before, mileage didn't improve btw). I see no point in continuing this discussion so I'm out.
 

·
Registered
Joined
·
16 Posts
Gmtegear, much appreciate your elucidations of the terms used. BTW, and thoughts on the BMW recommended S85 oil change interval 2000km/1200miles? My mechanic who seems to know his stuff thinks it's a joke, and 3000-5000miles is good enough. Clearly, changing oil even ever 100miles is not going to hurt the engine, just make the oil provider happier (i use LiquiMoly 10w60) for the increase in sales! Also, my mechanic recommends an additive Ceratec by LiquiMoly,
Anybody has anything positive to say about it? Any measurable improvement in performance, critical parts longevity, or milage ?
It would add about 40% to the oil cost, hence the question if it's worth it. I've always been skeptical of the added value of oil additives. If they are so great, why the oil manufacturer did not put it in the original oil product? Please chime in. Albert
 

·
Registered
Joined
·
109 Posts
Gmtegear, much appreciate your elucidations of the terms used. BTW, and thoughts on the BMW recommended S85 oil change interval 2000km/1200miles? My mechanic who seems to know his stuff thinks it's a joke, and 3000-5000miles is good enough. Clearly, changing oil even ever 100miles is not going to hurt the engine, just make the oil provider happier (i use LiquiMoly 10w60) for the increase in sales! Also, my mechanic recommends an additive Ceratec by LiquiMoly,
Anybody has anything positive to say about it? Any measurable improvement in performance, critical parts longevity, or milage ?
It would add about 40% to the oil cost, hence the question if it's worth it. I've always been skeptical of the added value of oil additives. If they are so great, why the oil manufacturer did not put it in the original oil product? Please chime in. Albert
3000-5000 is definitely fine . BMW never recommended 1200 mile OCIs AFAIK. In fact, quite the opposite. I believe it was 12000-15000 miles. There are many opinions on OCIs. Stick with what you are comfortable with. I personally do 5000 mile intervals because oil is cheap in the grand scheme of things. I know flaco does OCI's up near 10000 miles if I'm not mistaken. As far as Ceratec goes, evidence for its benefits seems to be largely anecdotal. I'm not going to weigh in on that, you may choose to either go with your mechanic recommendation or do further research on the topic. It won't hurt the engine to add if you decide to do it.
 

·
Registered
Joined
·
410 Posts
LM makes great if not the best high end products, I use their 0w40 for winter, because I start up my cars and do some driving on the property every week. LM regularly wins multiple awards conducted my the German magazines, which do an EXCELLENT scientific review and comparison. We have nothing like that in the US, except perhaps for Consumer Reports, but they never get too far in to stuff like wiper blades, filters, and oil. I personally think Ceratec is a bit of a marketing gimmick, I'd rather have more moly and zinc, but too much zinc will wreck your O2 sensors and cat, so stay away from the "racing only" formulations.

Mobil1 makes great products too in the 0w40 and 5wXX, it is available everywhere and very economical. Buy it at Walmart or Costco. The interval depends greatly on how you drive the car. One thing you may consider is whether or not the oil heats up sufficiently to boil off the water that condenses within your engine and drains to the oil pan. There are also other acids too that are a byproduct of the combustion. Most people don't realize just why running with short low mile trips are "bad"/undesirable for the engine.

It's hard to find a oil manufacture nowadays that doesn't make a good product, but I chose things based on some specific criteria. I also make sure first that my bearings have been swapped since the factory tolerances are way too tight. You won't ever know unless you measure, and that may be extreme, but that's the engineer in me. When BMW finally published the nominal clearance (read: ideal target clearance), it ended up being 0.0009" or 0.022mm (22 microns). Note that with standard deviation, it could be smaller. The BMW min spec is 0.0004" or 10 microns. That is ridiculous and it explains the oil starvation failure mode.

The oil change intervals recommended seem excessive but I can understand why they specified such a narrow window. Castrol's 10W60 has proven to sheer at high heat, meaning the thickness breaks down and so it actually thins out. BMW specified such a thick oil for several reasons, but we can't be sure what they all are. Generally when an engine operates at high RPM it will generate alot of heat and the mechanical parts need a thicker oil since thinner ones will "run off" like water would. Blackstone would be useful for understanding the extent to which the oil has broken down, but as far as predicting wear on your rod bearings, I've stated prior that it is next to useless.

With my spirited street driving, I would do 5-8k intervals. On the M5, I plan to track I will likely do it every 3-4 track days. Consider if you live in dusty areas or do alot of stop and go as factors to change more frequently.
 

·
Registered
Joined
·
410 Posts
AFAIK bearing failures don't exclusively occur in cold climates either. Lots of cars were sold in CA and TX and failures happened there as well.
Correct I've never said that it is an exclusive cold climate failure mode. Oil starvation can happen when it is 120 deg F in Arizona, if the bearing clearance is insufficient. Statistically speaking given the lower tolerance value that BMW has published, 8-20% of all cars have/(had) bearing clearances of 0.0004" (10 microns) or even smaller. All the early failures seem to show that BMW did not use go/no-go gauging (or absolute measurement) on the crank journals. They could have easily solved this with 3 different rod bearing sizes, but they chose one size fits all.

People should change their bearings proactively if they have over 60k miles on the car. This advice is not uniquely mine, it is sound advice to avoid engine failure. It's smart to be proactive. If you hear rod knock shut the car off immediately.
 
41 - 47 of 47 Posts
Top