Blown motors, Rod Bearing failure S65 Registry.

[jcolley]

Originally Posted by Sneaky Pete

Man who fixes engines has engines to fix...is hardly surprising
He has "fixed" 8-9 (non stuck fuel injector) S65 engines this year...thats a relatively small number.
Ask any USA BMW M engine rebuilder how many engines he had had in over the same period and it would not be a small number at all.

Trying to make an apples to oranges comparison never works out well.

Well I asked a few dentists how many they had built and didn't get the answers I wanted, so asked another engine builder instead. That's the game we are playing here, no?

He clarifed that he was referring to rebuilds from spun bearings. And you are correct, I've built more than that this year because they are 90% of my business. I don't deal at all with other motors. Hard to scroll back on mobile to see your exact statement, but think his 8-9 is greater than your 2-3 a year isn't it?

I fully agree apples to oranges when you restrict your input data to two different forums and assume the demographic consistency of owners/members/failures/public posting bewteen the two.

[Scharbag]

Nice to see SneakyPete is at it again... Even though he is on my blocked list, I still see when people quote him.

The internets are full of characters...

[Ximian]

Originally Posted by Sneaky Pete

What also complicates things is that it appears that cars that had RB replacements with oem spec bearings that were later pulled apart for inspection had bearing in good condition.

I've seen this mentioned before but what are the sources? If it's true, it points to the rod bearing wear being caused at assembly by BMW or by rod bearing bolt defects.

[Helmsman]

Originally Posted by Ximian

I've seen this mentioned before but what are the sources? If it's true, it points to the rod bearing wear being caused at assembly by BMW or by rod bearing bolt defects.

Who ever replaced the shells Im sure will be careful with warm up and oil change, which also would be a factor.

[redline9001]

Originally Posted by Helmsman

Who ever replaced the shells Im sure will be careful with warm up and oil change, which also would be a factor.

I have owned my car since new and did all of these things... it was not a factor... I replaced my bearings and they were bad shape...

People just need to release that it needs to be done... unless you like gambling

[IanMan]

Sneaky Pete is the type of guy that would smoke 3 packs a day and then deny that he got lung cancer....

[Helmsman]

Originally Posted by redline9001

I have owned my car since new and did all of these things... it was not a factor... I replaced my bearings and they were bad shape...

People just need to release that it needs to be done... unless you like gambling

Did mine too mate (37k, slightly worn but fair shape) so totally agree you want to do it to be on the safe side, even more so if not first owner. Still, most S65s still run strong out there where Im assuming proper treatment in combination with "good" engine example/limited tolerance stack up helps.

[Sneaky Pete]

Originally Posted by jcolley

Well I asked a few dentists how many they had built and didn't get the answers I wanted, so asked another engine builder instead. That's the game we are playing here, no?

Oh come on....stop being disingenuous.
But just in case you aren't as smart as I think you are...Let me try again.:
I poll 1000 people asking how many of them smoke and get an answer.
You dispute the answer by saying the big supermarket has 100s of unique customers who buy cigarettes.
A like for like comparison between the biggest UK M3 website and the biggest USA M website is certainly not perfect but its workable.

Originally Posted by jcolley

[...], but think his 8-9 is greater than your 2-3 a year isn't it?

Mathematically it is indeed...but its irrelevant in the same way that taking your statement that you rebuild more than he does, backs up my point.

Originally Posted by jcolley

I fully agree apples to oranges when you restrict your input data to two different forums and assume the demographic consistency of owners/members/failures/public posting bewteen the two.

Really?
Both sets own E92 M3s, both tend to report engine failures, either their own or ones they know off.
Last time I checked....the UK was the biggest importer of M cars per capita (outside of Germany obviously)....so we are equally as enthusiastic owners as the USA.
There is nothing to suggest that there is a distinct difference between owners that could account for different failure rates.

I get that you guys don't have the same perspective...you assume that what you see in the USA applies equally to all M3 markets...but it doesn't.

Some of logic mangling needed to keep the too tight bearing clearance theory train on the tracks is pretty epic though.
There was one the other day..something about the reason the guy had 145k miles on his car was because it must have been built with a loose clearance at the factory!
Seriously I kid you not...it simply not occuring to him that the same logic equally applies to most any car with a decent mileage, and thats a lot of cars.

Anyway I'm out for the day...but when I log on later, I'll be expecting plenty of insults from the usual suspects...and don't hold back, because it doesn't at all make you look petty and half witted.

[Helmsman]

Originally Posted by Sneaky Pete

Oh come on....stop being disingenuous.
But just in case you aren't as smart as I think you are...Let me try again.:
I poll 1000 people asking how many of them smoke and get an answer.
You dispute the answer by saying the big supermarket has 100s of unique customers who buy cigarettes.
A like for like comparison between the biggest UK M3 website and the biggest USA M website is certainly not perfect but its workable.



Mathematically it is indeed...but its irrelevant in the same way that taking your statement that you rebuild more than he does, backs up my point.



Really?
Both sets own E92 M3s, both tend to report engine failures, either their own or ones they know off.
Last time I checked....the UK was the biggest importer of M cars per capita (outside of Germany obviously)....so we are equally as enthusiastic owners as the USA.
There is nothing to suggest that there is a distinct difference between owners that could account for different failure rates.

I get that you guys don't have the same perspective...you assume that what you see in the USA applies equally to all M3 markets...but it doesn't.

Some of logic mangling needed to keep the too tight bearing clearance theory train on the tracks is pretty epic though.
There was one the other day..something about the reason the guy had 145k miles on his car was because it must have been built with a loose tolerance at the factory!
Seriously I kid you not...it simply not occuring to him that the same logic equally applies to most any car with a decent mileage, and thats a lot of cars.

Anyway I'm out for the day...but when I log on later, I'll be expecting plenty of insults from the usual suspects...and don't hold back, because it doesn't at all make you look petty and half witted.

There are no insults Pete - I see much more of that going on over at M3Cutters - but simply curiosity of your S65 vs S85 view and why the latter seem to fail more.

Cheers
Nik

[jcolley]

Originally Posted by Sneaky Pete

There was one the other day..something about the reason the guy had 145k miles on his car was because it must have been built with a loose tolerance at the factory!

Not familiar with that particular discussion, but *loose tolerance* or *looser tolerance stack-up*? One of those is absurd, the other is a sound forensic engineering conclusion IMO.

[Bartledoo]

Originally Posted by jcolley

Not familiar with that particular discussion, but *loose tolerance* or *looser tolerance stack-up*? One of those is absurd, the other is a sound forensic engineering conclusion IMO.

The guy probably meant loose "clearance". For some reason people frequently interchange clearance and tolerance.

[deansbimmer]

Originally Posted by jcolley

Not familiar with that particular discussion, but *loose tolerance* or *looser tolerance stack-up*? One of those is absurd, the other is a sound forensic engineering conclusion IMO.

You know Jim.....Trolls die if you don't feed them.

[dv13]

Here is an example thread of an OE replacement not showing wear on an engine that had shown a lot of wear on the original bearings.

https://www.m3post.com/forums/showthread.php?t=1530890

There was also another reference to a similar result in another of these marathon bearing threads...

Wanting to understand why this might happen, since it runs counter to the tolerance stack theory, does not a troll make.

I personally just want to understand the root cause of the problem so I can make the best bearing service choice. If that happens to be OEM or a coated/treated bearing that results in the original spec clearance but with better/properly torqued bolts, that works for me. Arbitrarily increasing the clearance without understanding the root cause seems to be one answer, but the jury will be out for some time on whether or not it’s the best one.

[deansbimmer]

Originally Posted by dv13

Here is an example thread of an OE replacement not showing wear on an engine that had shown a lot of wear on the original bearings.

https://www.m3post.com/forums/showthread.php?t=1530890

Hardly a post worthy as scientifically valuable evidence. Even so, it does not run counter to the tolerance stack issue because we don't know the starting dimensions of the original (or replacement) bearings, or anything else about the engine's origin, maintenance history, usage environments or habits, etc. Or similar parameters revolving around the second bearing set.

Bearings with increased clearances were not produced arbitrarily. Unless, that is, that in your mind the only valid reason for an increased bearing dimension is by BMW officially stating one themselves (not happening). Federal Mogul, other OEM's, and the entire aftermarket engine building community has for a very long time held a standard suggested dimension of .001" per journal inch for bearing clearance, a dimension that our OEM bearings fall significantly short of. That dimension was not determined at random either, so the aftermarket S65 bearings simply manufacture bearings with that as the target.

90% of the all readable online material revolving around this issue are examples of the blind leading the blind. Endlessly regurgitated until it's assumed fact.

[Sneaky Pete]

Originally Posted by Helmsman

but simply curiosity of your S65 vs S85 view and why the latter seem to fail more.
Cheers
Nik

Hi Nik...I can give you a view but as I haven't really followed the S85 story that much, I can't say how well it will stand up to scrutiny. But anyway...
IIRC BMW built the S85 to try and cash on its F1 programme by building an engine loosely based on its F1 V10 race engine....and I have the impression they may have packaged it a little too tightly...and the original design would have benefitted from a wider rod bearing crank journal.
In any case they went with a rod bearing clearance that is popular in mainstream car manufacturing (although mostly in conjunction with a lower viscosity oil).
As always, warranty replaced engines were returned to the factory for disassembly to discover what, if anything, could be done to reduce the cost of warranty engine replacements by redesigning components or changing clearances.

So when it came to designing the S65 they had a quandary...they knew that the S85 engine was susceptible to certain failures but by using a cut down version of it, it saved a fortune in R&D costs compared to a whole new V8 engine design.
So BMW worked on the weaknesses they could, changing the high pressure Vanos and upgrading the ion sensing anti knock hardware. The marginal ability of the rod bearing oil film to resist high combustion pressures (showing as accelerated rod bearing wear) however couldn't be resolved, without a costly engine redesign so they settled with optimising what they had (improving the anti knock system).
They already had a bearing clearance they were happy with, increasing it would not make the bearing wear rate any better...increasing bearing clearance reduces the area of the oil film area that is under load. And they needed to keep the Castrol 10W60 oil because it has a robust oil film strength under high load/temp.
The downside of 10W60 oil is that the engine must be warmed up before subjecting the engine to high loads..so BMW designed a warning system into the rev counter in the E9x M3s...something some owners likely ignored.

So back to the question...why do S85 seem to fail more.
Obviously they are an older engine, more miles more hours.
I believe the high pressure vanos was problematic.
As were injector problems.
And I think the ion sensing anti knock system (unpopular in mainstream car manufacture) was far from perfect in the S85 design.
Logically BMW optimised that design for the S65 as best they could at the time and as a result the S65 does seem to be more reliable.

I think its likely that the S65 engine failure rate (due rod bearings) will slow down now as the majority of cars that left the factory with out of tolerance rod bearing clearance due manufacturing inadequences have already failed (by 60k miles it seems) and then as cars get older and acquire more miles the engine fail rate will eventually start to pick up again on cars with original bearings.
I didn't track S85 engine failures but it wouldn't surprise me if it followed a similar pattern.

It is my belief that the changes in the hardware of the ion sensing anti knock system had benefits especially when combined with the various software updates issued by BMW. The principle benefit being better combustion control and therefore less variance in the load on the rod bearing oil film.

I believe the (now dropped by BMW) ion sensing anti knock system was in the early years not especially comfortable with changes in fuel octane rating and volumes of ethanol...but it did seem to be better after the mid 2012 software update. That the EU enforces quite strict control over fuel in its markets, particularly octane and ethanol levels (compared to the USA) may account for the lower incidence of engine failures in the UK.

It could also account for why engines that have had replacement OEM clearance spec bearings fitted, look fine when later dismantled...although that assumes they benefited from running the later software (and that made a difference).

In any case both the S85 and the S65 seem to have a marginal ability of the rod bearing oil film to resist high cylinder combustion pressures...and BMW with all the data, decided increasing the clearance was not going to help that.

[Sneaky Pete]

Originally Posted by pbonsalb

I don’t think BMW had much S85 rod bearing failure data in 2007 when the S65 came out. The S85 had been around for 3 years at that point.

They will have had the numerous engines that they themselves ran to destruction on test beds. All the cars from the test fleet, the ones run for NVH testing, the ones run for cold and hot environment testing, etc etc.

And if the S85 followed the pattern seen in S65 engines (but slightly more pronounced) then they will have had quite a few low mileage warranty returned engine failures to pull apart.
But yes they won't have been swamped with failed engines...but they will surely have known exactly what the weak points of the engine were.

[aus]

Can you guys pick one of the 50 other threads to discuss this?
I'd like to keep this for posting blown engines.
Thanks.

[jcolley]

Originally Posted by aus

Can you guys pick one of the 50 other threads to discuss this?
I'd like to keep this for posting blown engines.
Thanks.

Agreed. Deleted my posts.

[NeverL8]

Add another one

Aarchuda

https://www.m3post.com/forums/showthread.php?t=1573810

[RedScytheM3]

Originally Posted by TheRussski

Add another one

Aarchuda

https://www.m3post.com/forums/showthread.php?t=1573810

Does this qualify to be posted here?

[Helmsman]

Originally Posted by RedScytheM3

Does this qualify to be posted here?

Nope.

[aus]

Originally Posted by RedScytheM3

Does this qualify to be posted here?

First line says engine blew due to bearings.
.