High mileage 08s report in!

08 transmit a little more gearbox noise.

wfdeacon88 wrote

"RB wear and engine failures are two separate abnormalities."

So when the RB wear goes down to the copper (on older style bearings), and we see a spun bearing and engine failure, that worn bearing had absolutely nothing to do with it? Your logic makes no sense. Why don't you just not do your bearings and quit talking about it.

You have not understood the logical argument. Your bias is emotionally motivated either by fear of mechanical failure or the money you wasted on RBs replacement. It's called the sunk cost cognitive bias. Let me guess, you bought a used M3 and wasted $2,000+ on RB replacement after blindly accepting the RB theory for face value. Naturally you hate logic that indicates this to you. I understand, i really do. However, I am following unbridled logic and pointing to the lack of proof and the irrational, empirical and emotionally driven argument that underline the S65 RB theory. I saw it take shape from the beginning. Don't get emotionally loaded, stick to logic. Let me ask you the following logic question :

So, when a finely running 150k -200k miles S65 engine was taken apart and the bearings looked very worn, the bearings had nothing to do with the engine never failing ?

Finding worn bearings in a destroyed engine is not proof itself. It's called : available cause heuristic bias. There are many other factors/causes to consider in engine failures. An analogy is best employed here to distance yourself from the emotional financial bias you have. Suppose a fatal disease causes among other symptoms a skin condition and internal organ deterioration, the latter being fatal in 1% of cases. Some people are found dead covered with the skin condition. Somebody conjectures that the skin condition caused their death due to inflammation. A smart business man finds a cream that treats the skin condition, however unbeknownst to them (or even the businessman) it does not heal the disease. People start buying the expensive cream in droves. Somebody says the cream is useless for curing the disease and receives an emotional/biased angry response from people who invested in the expensive cream and don't want their fear re-ignited. But here they find a dead person who was known to have been using the cream. The logical implication of that finding are ignored, having sold their mind to a supposed solution suppressing fear is more important to them than logic. This is the working placebo myth.

Back to the S65. There are cases of people that replaced RBs and their engine still failed a few thousand miles later. Logic dictates that the occurrence of such counter-proof invalidates the theory that RB are the cause of S65 engine failures. There are several such cases, attributing it to bad re-assembly work alone is not possible. Also, there are forgotten cases of very low mileage M3s failures (still being broken in) back in the early years.

I invite you to analyze your own statement : "Why don't you just not do your bearings and quit talking about it". It is summoning fear to ignore logic and give in to irrationality. It would be illogical for me to accept a disproved theory even if it is popular and mainstream. This is groupthink cognitive bias and can even turn to group pressure conforming.

I am saying, worn bearing can destroy engines but destroyed engines are not at all necessarily caused by worn bearings. A flawed engine design can cause worn bearings as a symptom, yet be very tolerant of it and not spin it long before the main cause blows the engine. There is evidence of this with 150k - 200k engines running strong on worn factory bearings. The flawed engine design however can cause the failure without the bearing being worn. This has been the case with replaced bearings engines failures + very low miles engine failures.

Of course there is merit in replacing worn bearings. But to motivate it or advertise it as a fix for blown s65, given the known history of s65 failures, is illogical.

At least you have not sunken to ad-hominem (attacking your opponent in an attempt to undermine their argument) and I hope you don't think that i have in any way, I apologize if you think i have, it is not my intent. Ad Hominem answers or with hints of it lack merit. I shall not reply but will report them. Let's keep it civilized we are all M3 owners.

When taking position against a majority / groupthink cognitive bias, answers of logical fallacies and cognitive biases are to be expected.

I dunno man. Bearings worn to the copper + copper in the oil filter + rod knock + dead motor seems like probable cause to me. Maybe not empirical by scientific standards, but ya know, if it tastes and smells like shit, well...

To be clear, I don't think anyone is claiming rod bearings are the ONLY reason S65s grenade, just the most common.

Rajmun340 wrote

Back to the S65. There are cases of people that replaced RBs and their engine still failed a few thousand miles later. Logic dictates that the occurrence of such counter-proof invalidates the theory that RB are the cause of S65 engine failures. There are several such cases, attributing it to bad re-assembly work alone is not possible.

I agree there are only several cases of engines with replaced rod bearings failing out of the thousands of engines with replaced rod bearings, and in those several cases, the problem was something else.

I disagree with your claim that insufficient rod bearing clearance had not caused excessive rod bearing wear and, in hundreds of cases, engine failures.

Rajmun340 wrote

wfdeacon88 wrote

"RB wear and engine failures are two separate abnormalities."

So when the RB wear goes down to the copper (on older style bearings), and we see a spun bearing and engine failure, that worn bearing had absolutely nothing to do with it? Your logic makes no sense. Why don't you just not do your bearings and quit talking about it.

You have not understood the logical argument. Your bias is emotionally motivated either by fear of mechanical failure or the money you wasted on RBs replacement. It's called the sunk cost cognitive bias. Let me guess, you bought a used M3 and wasted $2,000+ on RB replacement after blindly accepting the RB theory for face value. Naturally you hate logic that indicates this to you. I understand, i really do. However, I am following unbridled logic and pointing to the lack of proof and the irrational, empirical and emotionally driven argument that underline the S65 RB theory. I saw it take shape from the beginning. Don't get emotionally loaded, stick to logic. Let me ask you the following logic question :

So, when a finely running 150k -200k miles S65 engine was taken apart and the bearings looked very worn, the bearings had nothing to do with the engine never failing ?

Finding worn bearings in a destroyed engine is not proof itself. It's called : available cause heuristic bias. There are many other factors/causes to consider in engine failures. An analogy is best employed here to distance yourself from the emotional financial bias you have. Suppose a fatal disease causes among other symptoms a skin condition and internal organ deterioration, the latter being fatal in 1% of cases. Some people are found dead covered with the skin condition. Somebody conjectures that the skin condition caused their death due to inflammation. A smart business man finds a cream that treats the skin condition, however unbeknownst to them (or even the businessman) it does not heal the disease. People start buying the expensive cream in droves. Somebody says the cream is useless for curing the disease and receives an emotional/biased angry response from people who invested in the expensive cream and don't want their fear re-ignited. But here they find a dead person who was known to have been using the cream. The logical implication of that finding are ignored, having sold their mind to a supposed solution suppressing fear is more important to them than logic. This is the working placebo myth.

Back to the S65. There are cases of people that replaced RBs and their engine still failed a few thousand miles later. Logic dictates that the occurrence of such counter-proof invalidates the theory that RB are the cause of S65 engine failures. There are several such cases, attributing it to bad re-assembly work alone is not possible. Also, there are forgotten cases of very low mileage M3s failures (still being broken in) back in the early years.

I invite you to analyze your own statement : "Why don't you just not do your bearings and quit talking about it". It is summoning fear to ignore logic and give in to irrationality. It would be illogical for me to accept a disproved theory even if it is popular and mainstream. This is groupthink cognitive bias and can even turn to group pressure conforming.

I am saying, worn bearing can destroy engines but destroyed engines are not at all necessarily caused by worn bearings. A flawed engine design can cause worn bearings as a symptom, yet be very tolerant of it and not spin it long before the main cause blows the engine. There is evidence of this with 150k - 200k engines running strong on worn factory bearings. The flawed engine design however can cause the failure without the bearing being worn. This has been the case with replaced bearings engines failures + very low miles engine failures.

Of course there is merit in replacing worn bearings. But to motivate it or advertise it as a fix for blown s65, given the known history of s65 failures, is illogical.

At least you have not sunken to ad-hominem (attacking your opponent in an attempt to undermine their argument) and I hope you don't think that i have in any way, I apologize if you think i have, it is not my intent. Ad Hominem answers or with hints of it lack merit. I shall not reply but will report them. Let's keep it civilized we are all M3 owners.

When taking position against a majority / groupthink cognitive bias, answers of logical fallacies and cognitive biases are to be expected.

Bearings replaced with new oem bearings still would have tolerances that are arguably dangerous for such a high strung engine running such thick oil.

Not a lot of failures with increased tolerance bearings.

There's not a good competing theory. Your theory about thin walls and vibrations doesn't yet seem to be convincing many people.


I wish internal information from BMW would leak out. Surely they would have done an investigation or at least the engineers would have discussed it after blown engines turned up, so I'm sure they either know the cause or have a theory.

The alternator has a clutch on these? That's a new one to me (I know they have regenerative charging though), I'll have to check it out, I know lots of diesel alternators have one way clutches, but that's for a different purpose.
Maybe realoem will show me? Or newtis.....

Eja144
Good to know, thanks .
Just from my experience on other cars, plus the fact it goes quiet when you dip the clutch, where the gearbox input shaft slows then stops, which matches the noise pattern. If the spigot bearing in the flywheel was noisy it would do it all the time. A noisy thrust bearing is most likely to be noisy when pressing the clutch, but they can be noisy when pedal isn't being touched too.

pbonsalb wrote

08 transmit a little more gearbox noise.

Interesting, how did you find this out? And did you find out why? More sound insulation later on? Gearbox design tweaks?

I still think the cold start rattle is top end engine noise, but I'll try the AC off point next time.

Rajmun340
Again, interesting points you make in reply to wfdeacon88.
And yes the evidence is empirical that supports the RB failure 'theory', but that said it would seem to be the most probable cause of actual failures (not including pre-emptive changes again), I would say that it is a logical theory as we don't have any other that matches the data. And again I ask, unless you do?
Also it would be useful to your argument if you could at least post links to those engines that have had RBs done & then failed, expecting people to take you at your word on a controversial claim without any evidence to back you up is in itself illogical!

For the record, I've owned my e92 M3 for (just) over a month, it's not had the RBs done, and for the time being I have no near term plans to. Nor have I yet had oil analysis done (still looking into that).

Nothing to do with insulation. Lighter flywheel and or clutch weight. Heavier dampens sound more. All light flywheels transmit more of the sounds that are in the gearbox.

Ah I see, although my one had the clutch & flywheel changed 1-2yrs ago, so I would think that would be a later designed one.
Anyway, I'm quite happy to live with the noise if it's fairly normal for these, I think the last gearbox I stripped was on my Mk1 Ford Fiesta 1.1 in the late 80s! Lol, so I don't fancy doing it again now!

Eja144
Forgot to ask, how many miles have you done on your M3? And what's its total mileage?

Assimilator1 wrote

Eja144
Forgot to ask, how many miles have you done on your M3? And what's its total mileage?

I bought mine in June with a little over 59k and have since put about 3500 miles on.

Had the rod bearings replaced preventatively about a month into ownership. They looked pretty rough when they came out but I've seen way worse with fewer miles.

Do you have any future mods or work planned for yours?

Ah ok, so you've not had it long then, I take it the gearbox noise hasn't got any worse in that time then?
Did you post pics of your RBs?

As for mods, not really, although I maybe forced to partially de-modify it's silencer , it's had the 2 pipe mod & it sounds fantastic , but I had it sound tested as I want to do a few track days a year. The general limit is 105 dB, my car registered 103.4 dB! And the (cheapo, £10 ebay) meter we used has an error of +/- 1.5 dB! So too close for comfort I think. But 1st I need to get a more accurate test done.

As for more general work, I've got a coolant temp sensor code & inlet air temp codes which come back (but strangely the MIL doesn't light up), so I need to sort that out (see this thread if you want to know more, or want to add info). Also I'm getting codes for both mirror heaters not working (& confirmed), so got to look into that too. Atm I can't even find which fuse powers them! The fuse card doesn't say, heating is a different supply to the motors btw.
Anyway, better bring this thread back on topic

Got pics of your M3 somewhere btw?

Jesus Christ this thread is full of people talking about rod bearings and fretting about their cars with low enough miles to still be CPO - we should start a new one

Or better yet, just lock the entire general sub forum

pbonsalb wrote

08 transmit a little more gearbox noise.

Why is that pbonsalb?

Eja144 wrote

Sounds like something rotating in an elliptical pattern behind the stereo area of the dash. off

Yes! That's exactly the noise I get on re-engagment of the clutch in neutral,sometimes it is fairly audible but I give it a couple of pumps or a nice slow release and it goes away. But yeah I have stopped worrying about after a while because the clutch and tranny still feel quite nice!

116k on factory Rod bearings
I've replaced one throttle body actuator motor and converted both to carbon gears from speedometer gears
rebuilt driver's rear brake caliper
aside from that I've washed, waxed, and changed the oil and brake fluid. Transmission wants to slowly shift from neutral sometimes so will do a transmission service, and there is a fuel pressure sensor that needs to be replaced. The driver's side catalytic converter has started deteriorating so I'll gut the primaries and just leave the secondaries in place.
The car has been super reliable and needed very little maintenance so I just do what needs to be done when it needs it.

4corners wrote

Why is that pbonsalb?

They have a lighter flywheel. People complained so BMW changed to a heavier flywheel to dampen sounds better. With a LTW flywheel on any car you hear more gear rattle from the trans.

Interesting, but mine should have the later design f/whl as it was replaced 2yrs ago.....
Maybe I'm just more aware of the modest noise due to my job (car mechanic/tech).

kawstik wrote

Goodwill relief from BMW NA? How did you go about that?

I asked the dealership. They put it in with NA and came back within a few hours, was pleasantly surprised. The car had been serviced exclusively at that dealership since my original purchase.

Ab28 wrote

Rajmun340 wrote

Second there is zero proven correlation between bearing wear and S65 engine failure. Unlike 90% of current forum members , i followed that debate when it emerged back in 2010,11,12 etc.. Absolutely no proven correlation exist. it's purely empirical. Yes the bearing are abnormally worn, but do cars with 150k, 200k+ miles still on original bearings have worn bearings ? The answer is Yes absolutely. Did the engine fail, nope. Bottom line, the correlation is a myth. RB wear and engine failures are two separate abnormalities. it's another fear generated business, $2,000 is welcome and starting a business on customer fear is guaranteed to generate revenues.

You must be kidding...to say that S65 engine failure and bearing wear are two separate things is probably the most incorrect bit of information I have read on this forum.

The engines are failing from bearing wear!

I agree that's big post is bs. My bearings blew at 75k and froze my engine. Had to rebuild the entire thing. Seems common with this engine. I ran my 330ci to 185k and bought it at 40k and never did the bearings go

Just changed my original RB at 129k, they were pretty worn.

To another 130k!

Woot!

Nice! , have you got pics of the old bearings to post in the rod bearing condition thread?
What year was your car? And what made you decide to change them?

Assimilator1 wrote

Nice! , have you got pics of the old bearings to post in the rod bearing condition thread?
What year was your car? And what made you decide to change them?

2008 M3, Built Date 03/2008, just a piece of mind to change it.

Plus now if anything happens I won't blame if was the old/previous owners with old RB.

The car is now under my watch, so I refreshed everything. I'll be the one to kill the car if it dies .

I got pics, I'll do a build thread in soon once I get everything dialed in.

Cool, let us know here if you could .