S65 Oil reports collation (most with rod bearing photos) - does oil analysis work?

[Assimilator1]

I started this list for myself a few months back when I heard a few comments that bearings had failed or were dangerously worn & oil reports had failed to show any problems. To be honest, I didn't really believe them, how could metal being shed not be picked up??
I expressed some doubt that they could miss problems, but largely stayed quiet about it & decided to gather some data. I was expecting to find that the oil reports were done long before the failure/bearing change, or that the bearings weren't in fact dangerously worn (referring to lead/copper bearings only, & by dangerously worn I mean showing copper). And to start with, that's what I found, although largely I was finding oil reports with high lead levels & when bearings were pulled, their were shot, like these.

Oil analysis confirmed bad bearings

nholmes - https://www.m3post.com/forums/showpo...5&postcount=17 and https://www.m3post.com/forums/showthread.php?t=1237264 - 2 bearings just gone through to copper, 2k miles on oil, 103k miles.

tom @eas - https://www.m3post.com/forums/showpo...58&postcount=2 , (3 bearings showing copper & 2 of them breaking up!) 106k miles.

tom @eas - oil report - https://www.m3post.com/forums/showth...1#post15421907 - bearing photos (Bmw M3 Guy's car) - https://www.m3post.com/forums/showth...5#post15421055 , 53k miles.

tom @eas - https://www.m3post.com/forums/showpo...&postcount=389 (surewin's car) 63k miles.

L4ces - https://www.m3post.com/forums/showpo...8&postcount=84 Oil report https://www.m3post.com/forums/showpo...3&postcount=89 , pb 24ppm, Fe 17. 0/40 was used for last 100k miles) 145k miles.

Richbot - https://www.m3post.com/forums/showpo...&postcount=681 (actually don't look that bad, no copper showing!) 102.4k miles.

Peertwelve - https://www.m3post.com/forums/showpo...&postcount=187 (although oil report not shown, pb 30ppm) 39k miles.

mmbv1000 - https://www.m3post.com/forums/showpo...&postcount=394 (although oil report not shown, "higher-than-average" levels of lead) 60.5k miles.

tubedreamer - https://www.m3post.com/forums/showpo...&postcount=558 (report shows pb 18ppm, shells fairly badly worn but no copper showing) 43k miles.

TheBreeze - https://www.m3post.com/forums/showpo...&postcount=563 (report not shown, but pb went from 4 to 10ppm between reports), copper not showing, but bearings quite worn. 87.8k miles.

willie92 - https://forums.m3cutters.co.uk/threa.../#post-2843648 (4 bearings to copper, pb 48) 65k miles.

radiognome - https://www.m3post.com/forums/showpo...&postcount=838 - Oil reports 'constantly showed higher than usual metals', bearings quite worn but not through to copper. 68k miles

Imapastokitshc - https://www.m3post.com/forums/showpo...&postcount=858 - 2000km oil report showed pb 19ppm, many bearings through to copper, 1 almost completely. 57k kms, 35.4k miles.

PRJ - https://www.m3post.com/forums/showpo...postcount=1007 - a few just gone through to copper. 41k miles.

LeveragedTiger - https://www.m3post.com/forums/showpo...postcount=1135 - 1 just worn through to copper 3k miles later. 37.1k miles

tom @eas - https://www.m3post.com/forums/showpo...postcount=1338 - alu brgs, report showing slightly elevated levels (including lead bizarrely!), 17k miles.

Yoko22R - https://www.m3post.com/forums/showpo...99&postcount=5, bearings not quite through to copper, 27k miles.

bvrider1 - https://www.m3post.com/forums/showthread.php?t=1337803, some bearings showing copper, 77k miles at oil report, bearings changed at 84k miles.

kimiraikkonen - https://www.m3post.com/forums/showpo...&postcount=731 (preventatively changed, 1 bearing scored by debris & showing a little copper. Earlier reports showed elevated lead). 118k miles.

M3MPH1S - https://www.m3post.com/forums/showpo...postcount=1520, (2 bearings showing copper, pb 18) 163k miles!

Silos - https://www.m3post.com/forums/showpo...postcount=1583 - elevated lead, copper & iron, changed preventatively, 3 bearings mostly down to copper! 97k miles

amrazM - https://www.m3post.com/forums/showpo...07&postcount=1 , approx 1/2 the bearings worn to copper (run in service missed!), slightly elevated levels of Iron & Lead. Advised further investigation due to metals showing over just 500 miles! 40k miles (on that 2nd engine).


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Oil analysis advised caution & to recheck in near future

wfdecon88 - https://www.m3post.com/forums/showpo...6&postcount=24 - oil report, Pb/cu 32/3 ppm. Photos https://www.m3post.com/forums/showthread.php?t=1562310 major wear to lead but no copper visible. 99k miles.

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Photos &/or oil analysis report, no claim either way

anerbe - https://www.m3post.com/forums/showpo...&postcount=967 - spun bearings, elevated pb on 2 reports! High copper on final one. Comments not shown for report prior to spun bearings. 54k miles.

kevin @ eas https://www.m3post.com/forums/showpo...&postcount=429 - high wear & some bearings juust showing copper, oil report @75.6k miles pb 6, (note significant gap between report and RB change), bearings changed @80k miles.

XKxRome0ox - https://www.m3post.com/forums/showpo...&postcount=726 - oil report was done 4640 miles before the bearings were changed, the old bearings were very worn, but don't appear to be showing copper. Bearings changed at 58.7k miles.

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Getting close now to missing failures, but not quite!......

Oil analysis stated bearings ok & although they are significantly worn, they weren't through to copper.

blueliner - https://www.m3post.com/forums/showpo...&postcount=937 (preventatively changed @46k miles)

ThatM3guy - https://www.m3post.com/forums/showpo...postcount=1256 (preventatively changed @120k miles).

s14_kev - https://www.m3post.com/forums/showpo...&postcount=777 - high wear, but no copper showing, report lead levels very slightly raised, comments conclude ok. Preventatively changed @110k miles.

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These 2 could be said as failed & missed by the reports, but I decided they just barely fell into the camp of not dangerously worn, especially subjective these 2 I know!

Oil analysis stated bearings were ok, were heavily worn but not majorly showing copper

Iyzmi - https://www.m3post.com/forums/showpo...&postcount=673 (1 bearing showing a little bit of copper, report showed a slight pb spike 5k miles earlier) preventatively changed @66k miles.

kimiraikkonen - https://www.m3post.com/forums/showpo...&postcount=731 - (high wear, although mostly not through to copper, 1 had a score to copper. Report levels ok, comments not shown). 118k miles.

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These 4 are in a grey area if you considered the levels & comments, the comments said ok, but IMO the levels were elevated. If you went by the comments conclusion, you could say they missed bad bearings.

Oil analysis said ok, but pb & Cu levels elevated + shells heavily worn or failed

stevecm3 - https://forums.m3cutters.co.uk/threa...esults.200149/ - although given all clear, report (Millers 5/18) shows pb was 20 ppm & Cu 9ppm, 4 shells to copper! 84k miles.

greg_p - https://www.m3post.com/forums/showpo...&postcount=980 - although given all clear, advised to retest in 1k miles due to raised pb levels. Pb was 22 ppm & Cu 8ppm, a few just gone through to copper, 35k miles.
(Millers 2/19, maybe they tweaked their policy??).

Barnzzz - https://forums.m3cutters.co.uk/threa...2#post-2883365 - no pics or photos there, says report had elevated copper but 'nothing to worry about', shells gave out 2k miles later (had an injector stick open, then another shortly after!, some months prior to shell failure). In a PM he states pb 41ppm & Cu 31 ppm! Post to link to video of shells - https://forums.m3cutters.co.uk/threa...2#post-2885098 80k miles.

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These were the final clincher for me (I found them late on in my hunting btw). Oil analysis can miss failed bearings!

***Confirmed analysis missed bad bearings***

delirium330 - https://www.m3post.com/forums/showthread.php?t=1300528 - Cu/Pb at 1 & 2, yet 1 bearing to copper!! Oil life 3092 miles. Bearings changed just ~1500 miles after report. 62k miles

IIAp3x - https://www.m3post.com/forums/showpo...3&postcount=11 (no photos of engine, but states that it blew up 1k after report! Photo of report), Pb/Cu 12/2 ppm. His extensive thread - https://www.m3post.com/forums/showthread.php?t=1119912 55k miles.

MMachines - https://www.m3post.com/forums/showpo...postcount=2109 - shells 4-8U have partially worn through to copper, last oil report (at 84,079 miles shows Pb/Cu at 3/2 ppm), later oil report -

View post on imgur.com

note on his reports, 'mileage' switches from Kms to miles at 2017, 84.3k miles.

sv848evo - https://www.m3post.com/forums/showpo...&postcount=736 - unknown mileage on oil, but more than 2800 miles. 1 bearing mostly worn through to copper! And a few others just gone through to copper. Oil report, pb 7ppm, Cu 3ppm, bearings changed 1k miles later. 75k miles.
His photos :-




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So their you have it, whilst my data collection is relatively small (it still took months to find & collate!, & I will add to it, last list update 22/3/20), it does show that oil analysis won't necessarily pick up problems.

How/why? Mostly, & probably predominantly because the high wear rate occurred at some point before the oil report(s). The only way it can be reliable is if the reports are done from the very 1st oil change, from new onwards!
(I found 1 owner who nearly did this, & he posted the results here, can't remember his name [update], I believe it was someone in the 'Oil Analysis Reports' thread (starts in 2009! Which btw is a good read if you want to get an overview of many oil reports), I'll have to go through it to see who it was. Might have been MTROIS, op of the thread, multiple reports combined here.
For reference m6pwr posted What's in our Castrol 10w-60 TWS' & run in service oil analysed.

If you change your rod bearings (with lead/copper ones) & then oil test with every oil change, then yea you can keep a good eye on them, but it won't necessarily pick up other problems (e.g high main bearing wear, unless you changed them too of course).
Oh incidentally, Iam FODI (whose now posted below), said that it's possible for metal particles to be broken down into such small or big particles that it would be missed by regular oil analysis anyway. I haven't been able to look into this particularly, so I don't know how likely that is. I may look into that further, but as I've decided not to rely on oil reports anyway it has a low priority for me. And I'm going to change the rod bearings anyhow on mine.

Btw, my background to this is that I bought a 2008 M3 e92 in November as my weekend/fair weather/occasional track car (never thought I'd be able to own such an awesome car!).
I joined the forum just before getting it, so a few of you know me now, thanks for all the input & PMs guys! I had wanted to use the oil analysis to keep any eye on my car's rod bearings, as I didn't fancy doing more car work in my spare time , as I'm a full time car tech/mechanic. (25yrs, mostly worked for inde garages, did a couple of 1yr stints at Nissan & Peugeot, now working for a Suzuki dealer (6+ yrs), not that makes much odds to this thread though ).
I've owned BMWs since 2004, and of course I work on them (bar recalls & MoTs).

[Helmsman]

Cheers mate, interesting compilation and "conclusion" (i'm aware data is limited but still).

"It does show that oil analysis won't necessarily pick up problems. How/why? Because the high wear rate occurred at some point before the oil report(s)."

To me another indication that most of the wear on fair/high milage shells we see that ran fine, probably are worn in its early life. Once shaved off they continue to do its job.
That said sure, still a good idea to replace them "early" to reduce risk.

[IamFODI]

Originally Posted by Assimilator1

how could metal being shed not be picked up??

...

...oil analysis won't necessarily pick up problems.
How/why? Because the high wear rate occurred at some point before the oil report(s).

...

Oh incidentally, I did hear from 1 guy (I forget who ), that it's possible for metal particles to be broken down into such small particles that it would be missed by regular oil analysis anyway.

FWIW, I addressed all of this and more here: https://www.m3post.com/forums/showpo...postcount=1261

[Assimilator1]

You're the guy I was thinking of , thanks for the link .
I'll tweak my conclusion.
But the main point of my thread was to show the data that oil analysis can miss bearing failure. Your post whilst interesting & useful (so I'll add it here), didn't show that.
Btw, would be useful to know what's your background to knowing this about oil analysis?

Which wear modes produce particles too big for ICP?

Helmsman
Thanks , and could well be, but without stacks of people showing oil reports from early on, we probably won't know for certain.
I'm thinking I should add the mileages to all the reports I've posted.......

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Incidentally, I'm surprised that I've only had 2 replies with over 130 views! lol.
I'm going to see if I can post the pics to my op with the case that demonstrated oil analysis can miss bearing problems.

[Assimilator1]

Post by IamFODI (same as linked by him above).

Originally Posted by IamFODI

Well... yes and no.

Like most oil analysis labs, Blackstone gets its wear metals counts from ICP spectroscopy, which only catches particles up to a certain size -- and not all mechanical wear chucks out particles in that size range. Some wear modes produce bigger particles, to which ICP spectroscopy is completely blind. Furthermore, ICP-detectable particles can come from chemical processes that have nothing to do with what most people would consider mechanical wear -- processes like acid attack from overextended oil change intervals, or highly active surface chemistry from aggressive anti-wear additives in the oil. So, if you see big numbers, it's difficult or impossible to say whether they're anything to worry about. And if you see low numbers, maybe everything's fine, or maybe there's a wear mode that ICP spectroscopy can't detect. You have no idea just from looking at the report.

S65s with the original BMW rod bearings are lucky in that they sometimes produce lead and copper particles in ICP-detectable sizes when their rod bearings wear abnormally, AND they don't seem to produce ICP-detectable lead or copper in significant quantities for any other reason (barring leaded fuel or new oil cooler hardware or something). So, if you see those high numbers from one of those engines, then yeah, it's probably rod bearings. But again, if you don't see those numbers, you have no idea.

We don't know how or to what extent the updated BMW rod bearings or any aftermarket rod bearings will show wear on ICP spectroscopy, if they even do at all. Aftermarket bearing manufacturers will say they went for leaded bearings to facilitate oil analysis, but there's been no rigorous testing of that idea and the data from the field is incomplete. What little evidence we have on the updated BMW bearings is not favorable, though we don't even know what we're looking for because we don't really know what they're made of.

ICP spectroscopy can be useful for tracking early-stage wear when you have a lot of background knowledge about the application in question. You have to know in advance whether and how any potential wear problems will show up on oil analysis, and you have to know about any possible sources of false-positives. Then you have to sample frequently enough to catch the wear while it's still in that early stage, before it starts producing particles too big for ICP spectroscopy to detect.

In other words, tracking wear with oil analysis requires a bunch of things that are difficult if not impossible for an end user, running oil with unknown chemistry, in a hand-built car engine with largely-unknown metallurgy, operated in the real world under uncontrolled and constantly varying conditions. And that's the main problem here.

It's generally assumed that frequent and regular sampling can reduce the futility of oil analysis in an application like this. That's why I'm doing it. But I'm sampling every 5k miles and using a slightly more extensive analysis package (Polaris Labs Advanced Engine Plus), and I'm not taking low numbers to mean a clean bill of health. I'm already planning to revisit my rod bearings within 60k-80k miles after the first change. What I'm looking for are signs that I might have to do them sooner, as well as signs of other kinds of trouble like fuel dilution and other contaminants -- which, by the way, is where oil analysis is truly useful in a car engine. Maybe that's another thread.

The set of oil analysis reports you had prior to changing your rod bearings wasn't so much a consistent history as a few snapshots over tens of thousands of miles. And again, that's in addition to the serious limitations of oil analysis for tracking wear.

Is what you did better than nothing? Absolutely.

Is it mysterious that oil analysis missed your rod bearing wear? Not in the least.

[IamFODI]

Originally Posted by Assimilator1

But the main point of my thread was to show the data that oil analysis can miss bearing failure. Your post whilst interesting & useful (so I'll add it here), didn't show that.

Absolutely. I was responding only to the points I quoted.

I agree that nothing makes the point better than evidence, and therefore what you've collected and presented here is vastly more important than the theory behind it.

Originally Posted by Assimilator1

Btw, would be useful to know what's your background to knowing this about oil analysis?

I'm not much more than a guy who listens to professionals in the field, honestly.

Originally Posted by Assimilator1

Which wear modes produce particles too big for ICP?

Don't think I could do much to improve on the answer I gave here: https://www.m3post.com/forums/showth...7#post25701187

[Assimilator1]

My memory sucks, so I appreciate the reminder .

[Assimilator1]

Added another case of ***Confirmed analysis missed bad bearings***.
Link to an oil report carried out just before the RBs change to follow [edit] now added.

[Assimilator1]

2 in a row! Added another case of analysis missed bad bearings.

[Assimilator1]

Added a couple of ambiguous cases from my data file to the 'no claim either way' section.
Added mileages to remainder of cases not previously noted.

Also I spotted an error by myself (& the owner) of the 'missed bearings' report for amrazM, aside from their 1st line, they had actually advised him to take further investigation due to the slightly elevated pb/cu levels that had occurred over just 500 miles!, and the visible metal he had reported seeing. I've now moved that case to the 'oil analysis reported bad bearings'.
Also added a new section 'Oil analysis advised caution & to recheck in near future', moved wfdecon88's case there (possibly others need to go there too).

38 reports in total
22 reports un-ambigouosly flagged bad bearings (~58%)
4 reports clearly missed bad bearings (10.5%)
The remainder weren't clear enough to come to a solid conclusion (e.g lacking info, bearings borderline, levels vs comments contradictory, too bigger a mileage gap between oil report & bearings removed etc)