Blown motors, Rod Bearing failure S65 Registry.

///M Power-Belgium wrote

There is NO correlation to mileage . I've seen RB failures with 6K ,9K, 11K , others with 100K + miles on it .
The failure list from our small Bimmerpost community (forum) is only the tip of the iceberg ...
*The Worldwide* S65/85 RB failures , that matters ! Bimmerpost is NOT the world .
It's a German lottery ...

I understand the forum is not the world. But if there are 300+ failures documented (someone mentioned that?), we might still be able to have some statistical inference on the data. For example I'm curious if the failure is completely random (a flat failure rate curve, or other shape? https://en.wikipedia.org/wiki/Bathtub_curve )

Mvy wrote

No direct correlation has been shown between SC and rod bearing wear. Most cars that blow up never had one.

I am willing to bet that I have seen RB failures on SC engines ("or was supercharged at one point) more than complete stock engines. But you can believe whatever you want.

Are the 2013 model years pretty much showing the same amount of failure as others? Just hit 20k miles and these threads are convincing me to just get it over with and replace them

ramo135 wrote

Are the 2013 model years pretty much showing the same amount of failure as others? Just hit 20k miles and these threads are convincing me to just get it over with and replace them

Yes.

ramo135 wrote

Are the 2013 model years pretty much showing the same amount of failure as others? Just hit 20k miles and these threads are convincing me to just get it over with and replace them

ONLY if they are the super rare Alpine White! lol

byroncheung wrote

I understand the forum is not the world. But if there are 300+ failures documented (someone mentioned that?), we might still be able to have some statistical inference on the data. For example I'm curious if the failure is completely random (a flat failure rate curve, or other shape? https://en.wikipedia.org/wiki/Bathtub_curve )

If you want to make a date/failure rate curve , you can do it with the list on page 1 => http://www.m3post.com/forums/showthread.php?t=786615
Open each link from the posted bearing failures and check the dates .
But your date/failure curve will never be accurate , because you/we have no information about the worldwide bearing failures .
Yours would be a Bimmerpost curve .

///M Power-Belgium wrote

If you want to make a date/failure rate curve , you can do it with the list on page 1 => http://www.m3post.com/forums/showthread.php?t=786615
Open each link from the posted bearing failures and check the dates .
But your date/failure curve will never be accurate , because you/we have no information about the worldwide bearing failures .
Yours would be a Bimmerpost curve .

Sure it won't be accurate to a tee, but this is statistically sampling, same as for e.g. polling before election. Is it 100% accurate? Obviously not. Is it completely useless? I don't think so. It's better than no info. As long as one is aware of its limitation, it still provide good info.

byroncheung wrote

Sure it won't be accurate to a tee, but this is statistically sampling, same as for e.g. polling before election. Is it 100% accurate? Obviously not. Is it completely useless? I don't think so. It's better than no info. As long as one is aware of its limitation, it still provide good info.

Not quite. You need random samples from the population of M3s or population of M3 RB failures, neither of which is currently possible for the general public to get. Polling is based on random samples of the us population.

Sephiroth wrote

Not quite. You need random samples from the population of M3s or population of M3 RB failures, neither of which is currently possible for the general public to get. Polling is based on random samples of the us population.

Yes, I agree, there will be sampling bias. This is one of the caveats one would need to keep in mind when interpreting the number.

However, I don't think the geography bias (that it's mostly US data point) is particularly problematic unless you think somehow there is something special about m3 being shipped to the US, or there are some special conditions in the US that correlate to the failure.

A more likely bias is that the population hang out on the forum might be a population that drives their cars harder, take the car to track etc, compared to general public. Something along that line will be more like to skew failure rate/pattern. But, I am probably more like an average forum guy than the general public anyway... so to some degree, that bias makes the result more relevant to enthusiasts readers...

byroncheung wrote

Yes, I agree, there will be sampling bias. This is one of the caveats one would need to keep in mind when interpreting the number.

However, I don't think the geography bias (that it's mostly US data point) is particularly problematic unless you think somehow there is something special about m3 being shipped to the US, or there are some special conditions in the US that correlate to the failure.

A more likely bias is that the population hang out on the forum might be a population that drives their cars harder, take the car to track etc, compared to general public. Something along that line will be more like to skew failure rate/pattern. But, I am probably more like an average forum guy than the general public anyway... so to some degree, that bias makes the result more relevant to enthusiasts readers...

I have put in about 70 records into my spreadsheet so far, this is the histogram of failure mileage... Obviously part of it is driven by the fact that there are probably more cars at mileage round 45-60k mile... I need to adjust for that fact somehow if i want the plot to represent failure rate / probability... But it does feel like if a car managed to survive past 60k mile, the chance of a failure after 60k is lower than before 60k...

byroncheung wrote

I have put in about 70 records into my spreadsheet so far, this is the histogram of failure mileage... Obviously part of it is driven by the fact that there are probably more cars at mileage round 45-60k mile... I need to adjust for that fact somehow if i want the plot to represent failure rate / probability... But it does feel like if a car managed to survive past 60k mile, the chance of a failure after 60k is lower than before 60k...

There's more to the story than simply tallying up the frequency of failure at an indicated milage. And you're going to have a tough time with the limited data to generate any kind of stats that can be predictive. You would need to account for a few handfuls of variables (driving styles, maintenance, modifications, environmental, gas, etc) and then perform some kind of factor analysis of mixed data. I doubt anyone has the time or care to do a proper study here and the final stats are going to be crude and blunt at best.

My work involves performing statistical analysis to determine the susceptibility, or risk, that children have of developing a leukemia. You can think of RB failure as a complex disease of a car much like we think of leukemia. Like leukemia in kids, there are many risk factors that predispose the M3 to to this complex state. To save everyone a lecture on statistical power, (appropriate) statistical significance testing, relative risk ratio and odds ratio - if you lack a sufficient population sampling and are missing many critical variables that play into RB failure then your data can only be descriptive (not predictive and certainly not able to make any associations). We can only take what you showed (or will show) with a huge grain of salt. You def cannot say that when you hit a certain mileage that your risk suddenly drops - whether the risk is high or low for a particular car at mile 0, the risk only goes up with time/mileage (increased wear, aging parts, etc) save for cars that just sit on display. I think a more appropriate inference from your histogram is that although RB failure has the potential to occur at any mileage interval on your x axis, the frequency is highest in mid mileage cars and the reason for that is poorly understood. As these cars continue to live and die we will continue gathering data, and maybe at some point we could have enough to do a proper retrospective study.

I'm glad someone is putting the data into a figure though. Seeing a visual representation of the available data is certainly more compelling that just seeing the total number of events.

I'm sure there's a dissertation on this somewhere, and if not then soon lol (or maybe for another car).

RedScytheM3 wrote

There's more to the story than simply tallying up the frequency of failure at an indicated milage. And you're going to have a tough time with the limited data to generate any kind of stats that can be predictive. You would need to account for a few handfuls of variables (driving styles, maintenance, modifications, environmental, gas, etc) and then perform some kind of factor analysis of mixed data. I doubt anyone has the time or care to do a proper study here and the final stats are going to be crude and blunt at best.

My work involves performing statistical analysis to determine the susceptibility, or risk, that children have of developing a leukemia. You can think of RB failure as a complex disease of a car much like we think of leukemia. Like leukemia in kids, there are many risk factors that predispose the M3 to to this complex state. To save everyone a lecture on statistical power, (appropriate) statistical significance testing, relative risk ratio and odds ratio - if you lack a sufficient population sampling and are missing many critical variables that play into RB failure then your data can only be descriptive (not predictive and certainly not able to make any associations). We can only take what you showed (or will show) with a huge grain of salt. You def cannot say that when you hit a certain mileage that your risk suddenly drops - whether the risk is high or low for a particular car at mile 0, the risk only goes up with time/mileage (increased wear, aging parts, etc) save for cars that just sit on display. I think a more appropriate inference from your histogram is that although RB failure has the potential to occur at any mileage interval on your x axis, the frequency is highest in mid mileage cars and the reason for that is poorly understood. As these cars continue to live and die we will continue gathering data, and maybe at some point we could have enough to do a proper retrospective study.

I'm glad someone is putting the data into a figure though. Seeing a visual representation of the available data is certainly more compelling that just seeing the total number of events.

I'm sure there's a dissertation on this somewhere, and if not then soon lol (or maybe for another car).

i'm well aware of the limitation of the attempt. even as i punched the data into the spreadsheet i realized the quality of the data is very spotty (lot of the reports consist of 1 liner that the engine has failed... it's going to be hard to have good consistent details of the incidents). it's just going to be a pet project of mine, which i think other people that are more numerically inclined like you and i are going to find interesting...

codinge90 for the list => http://www.m3post.com/forums/showthread.php?p=23399115

New_m3 for the list => # 81 https://www.m3post.com/forums/showthread.php?t=1446659&page=4

For codinge90, I saw a thread where he got a tune and then 2 months later after running on E85 car started acting up. Wonder how this factors in.

http://www.m3post.com/forums/showthread.php?t=1464063

Also, should we reference the videos in codinge90’s thread on the first page of this thread as good examples of ‘bad engine sounds’?

Also, cool pic of Ambiorix!

RedScytheM3 wrote

Also, cool pic of Ambiorix!

Thank you Sir !

GSTE34 for the list => # 17 https://www.m3post.com/forums/showthread.php?p=23443094#post23443094

Posted earlier in this thread about getting rod bearings replaced because i thought i was hearing ticking noise related to failing rod bearings. Fast forward couple months, had rod bearings replaced and also had the engine mounts replaced and oil dipstick installed. got the car back did the break in, didnt go over 3k rpm for 1000 miles and just did an oil change after about 1400 miles and found alot of aluminum shaving in the oil filter. i looked at the oil that came out of the engine and did not see any shavings in the oil. dumped couple quarts of cheap 5w30 and let it run through before refilling with fresh 10w60. The car also ran fine for the last 1400 miles except for a higher pitched metalic whine but no knocking. im hoping the whine is coming from the oil dipstick sitting against the heatshield or due to machtsnell air filter i installed around the same time. im guessing whoever drilled the hole in the oil pan for the dipstick bung forgot to clean the shavings out of the pan. I was pretty upset after seeing this and asked the shop to do an engine flush and then replace the oil with fresh oil again, however i dont trust the shop at this point since this is not the first time they screwed up. I was hoping if i do another oil change after a couple hundred miles that should flush anything else out. Any ideas?

https://photos.app.goo.gl/gt4428qeAjM6hTYA9

https://photos.app.goo.gl/7AVrGAJAyY9swJUA6

https://photos.app.goo.gl/YAUjXFMAWYAjuuEJ8

glacket wrote

Posted earlier in this thread about getting rod bearings replaced because i thought i was hearing ticking noise related to failing rod bearings. Fast forward couple months, had rod bearings replaced and also had the engine mounts replaced and oil dipstick installed. got the car back did the break in, didnt go over 3k rpm for 1000 miles and just did an oil change after about 1400 miles and found alot of aluminum shaving in the oil filter. i looked at the oil that came out of the engine and did not see any shavings in the oil. dumped couple quarts of cheap 5w30 and let it run through before refilling with fresh 10w60. The car also ran fine for the last 1400 miles except for a higher pitched metalic whine but no knocking. im hoping the whine is coming from the oil dipstick sitting against the heatshield or due to machtsnell air filter i installed around the same time. im guessing whoever drilled the hole in the oil pan for the dipstick bung forgot to clean the shavings out of the pan. I was pretty upset after seeing this and asked the shop to do an engine flush and then replace the oil with fresh oil again, however i dont trust the shop at this point since this is not the first time they screwed up. I was hoping if i do another oil change after a couple hundred miles that should flush anything else out. Any ideas?

https://photos.app.goo.gl/gt4428qeAjM6hTYA9

https://photos.app.goo.gl/7AVrGAJAyY9swJUA6

https://photos.app.goo.gl/YAUjXFMAWYAjuuEJ8

Sorry to hear that happened after all of the ruminating on getting it done in the first place and now having to worry about damage caused by the debris from the oil pan. I wonder if that metal is softer and if so if it means the risk of damage is low.

If the shop did the rod bearings, it would have had the pan off when drilling for the manual dipstick so there should be no shavings. If not drilled off the engine, then I can understand shavings getting in the pan. Many shops are not as careful as they should be, which is why I do my own work — most jobs require more care than skill and I care more about my car than most shops.

L4ces wrote

Sorry to hear that happened after all of the ruminating on getting it done in the first place and now having to worry about damage caused by the debris from the oil pan. I wonder if that metal is softer and if so if it means the risk of damage is low.

Im hoping i dodged a bullet here. i didnt see any metal in the oil as far as i could tell. I started hearing a metallic fluter after i got the car back but it runs good. i bought an oem air filter to see if sound was due to after market air filter. i think im going to bring it back to the shop and ask them to drop the pan, clean pan, flush the system and replace with fresh oil.