Poll: Have you replaced your stock bearings?

[IamFODI]

Originally Posted by tdott

Sorry to hear that.
OE everything is like the worse option available today.

I'm feeling pretty good about it, actually. But thanks for your concern.

[redline9001]

Originally Posted by Scharbag

My 2011 was produced in 04/10 and came with lead/copper bearings. I am not sure when the tin/aluminum bearings started being used in the manufacturing cycle. Does anyone have this information?

I would have to look again at my build date but it was right around yours and I had tin bearings in mine...

I always did proper warm up etc... low mileage... and for the miles my bearings were bad.

[KevM3UK]

Ive now sold my oem shells,Back to the drawing board now. What about an ACL shell and ARP bolt combo?

[Helmsman]

Originally Posted by KevM3UK

Ive now sold my oem shells,Back to the drawing board now. What about an ACL shell and ARP bolt combo?

Kev, I'd say if you have fair mileage on the car the main thing is to open up and get them checked and while there obviously replace them. What ever shells goes in will give you a fresh start. Whether OEM or increased clearance will prolong life over original bearings, up to you mate.

[NeverL8]

Originally Posted by KevM3UK

Ive now sold my oem shells,Back to the drawing board now. What about an ACL shell and ARP bolt combo?

Don’t put oem shells back in...Get extra clearance bearings like BE and VAC

[IamFODI]

Counterpoint: There isn't enough data from the field yet to show conclusively that the extra clearance makes the bearings last longer and causes no other problems.

The clearance hypothesis is reasonable has been extremely well substantiated. It has not been sufficiently tested. So, if you have to make a call on bearing replacement right now, it comes down to a value judgment.

Is a reasonable, well-substantiated hypothesis good enough for you to act on? In that case, go for bearings with extra clearance.

Or, do you not want to make the leap until the idea has been sufficiently tested? In that case, go with OE.

[Scharbag]

Originally Posted by IamFODI

Counterpoint: There isn't enough data from the field yet to show conclusively that the extra clearance makes the bearings last longer and causes no other problems.

The clearance hypothesis is reasonable has been extremely well substantiated. It has not been sufficiently tested. So, if you have to make a call on bearing replacement right now, it comes down to a value judgment.

Is a reasonable, well-substantiated hypothesis good enough for you to act on? In that case, go for bearings with extra clearance.

Or, do you not want to make the leap until the idea has been sufficiently tested? In that case, go with OE.

I agree that specific and statistically significant data for the S65 extra clearance bearings is not yet available. That said, there is 50+ years of engine building best practice that shows a minimum of 0.001"/1" clearance is required for high revving engines, not the ~0.00075"/1" nominal clearance of the factory S65.

So, as you state, we should be able lean on past experience to make an informed decision. I chose BE with BE ARP.

Cheers,

[NeverL8]

Originally Posted by IamFODI

Counterpoint: There isn't enough data from the field yet to show conclusively that the extra clearance makes the bearings last longer and causes no other problems.

The clearance hypothesis is reasonable has been extremely well substantiated. It has not been sufficiently tested. So, if you have to make a call on bearing replacement right now, it comes down to a value judgment.

Is a reasonable, well-substantiated hypothesis good enough for you to act on? In that case, go for bearings with extra clearance.

Or, do you not want to make the leap until the idea has been sufficiently tested? In that case, go with OE.

There has been few people that pulled extra clearance bearings out the cars with 35k miles + without any wear, and there’s also few people who pulled their 2nd set of OEM bearings with significant wear after just 12k miles... data is there and these samples backs it up. We will know more with time.

[IamFODI]

Originally Posted by TheRussski

There has been few people that pulled extra clearance bearings out the cars with 35k miles + without any wear, and there’s also few people who pulled their 2nd set of OEM bearings with significant wear after just 12k miles... data is there and these samples backs it up. We will know more with time.

Right. But given the variables involved, bearing pics from a few engines with 30k-40k amounts to basically nothing. When we have comprehensive info on several dozen engines with like 80k+, then it'll be time to talk.

Or maybe someone will commit enough resources to run a full OE-level engine bench test regime. I'm not holding my breath but you never know. :]

[Richbot]

I saw an owl eat a mouse once but I can't tell if owls eat mice without more data

Still, as a mouse, I tend to avoid all owls just in case

[Helmsman]

Originally Posted by Richbot

I saw an owl eat a mouse once but I can't tell if owls eat mice without more data

Still, as a mouse, I tend to avoid all owls just in case

.....

[cvstar9M3]

BE bearings/bolts coming soon my way!

[InnerBlueSkies]

Originally Posted by Richbot

I saw an owl eat a mouse once but I can't tell if owls eat mice without more data

Still, as a mouse, I tend to avoid all owls just in case

The Owl probably worked for BE.

[Teknically]

Long time reader and 1st post as I just got a great winter deal on a 2008 E90 M3.
Didn't keep my E46 M3 long enough to previously join...


ACL bearings and BE-ARP bolts ordered as the car is close to 120K, will post pictures on the other threads after removal

[Big boi m5]

Will rod bearings appear on the car fax?

I've recently bit a cheap high mile S85 with perfect 5k oil changes. It's only history that isn't. 'Maintenance' or 'service' is clutch at 45k, and transmission (SMG) at 99k.

I've noticed however the exhaust and CAT were removed and replaced, an aux port job was added, and the Idrive was updated. This leads me to believe not everything was labeled or shown in the car fax.

Also, the toe hook is exposed and the cover is missing, which leads me to believe the car has been tracked and It came with the correct manufacturer oil in the trunk. My hope is this is indications of a responsible knowledgeable owner.

I'm hoping the bearings have been done but it's not listed there.

Also just speculation, some of these blow up at 30k some get bearings done at 120k.

Could it be that it's actually disrespecting the break in period that causes the 90% major wear and then poor guys 30-80k miles later reap the consequences as the last 10% minor wear accumulates?

In my mind this explains the completely random blow ups.

For what it's worth the 3 big Indies in my area have said
1. BMW says you won't get wear if you don't rev above 7k and follow the recommended oil and warmup.
2. Oil analysis is only moderately sensitive (for anyone who hasn't taken a stats class this means it can detect wear but there are plenty of false negatives, so it's not reliable)
3. Don't do the bearing job if oil testing is negative
4. 2 of the 3 have combined only seen 2 failures and only one of 3 will even do the job as the other 2 don't think it's necessary.
5. The BMW Dealer in my area doesn't recommend doing the job.


All this talk on forums is sadly just talk. Because there is no actual data out there it's hard to say anything with weight.

If this topic was being discussed in a medical context the équivalent would be having a lung to prevent cancer. Or having a tooth pulled and replaced with an implant ($5k) if you have a little cavity.

I realize a bearing failure is catastrophic if it happens but I'm not convinced the general idea that everyone needs to do rod bearings is actually logical or how any of us would make a similar decision regarding our health.

In the hypothesis where a disrespected break in period is the cause of significant wear that means a vast majority of us would be driving in cars that will likely never need bearings.

If the BMW 7k rev hypothesis is true you can control your wear rate. And by the way I don't think you get any extra power past 7.5k anyway.

Another hypothesis would be an error in precision of the manufacturing. Some part of bearing or material that comes Into contact with the bearing is incorrect sized in a certain percent of engines leaving these bad engines doomed to fail while the majority others will not have a problem. Every manufacturing process like a drug for example has a built in allowed error. For example your does of 200mg penicillin could be 180mg or 220mg once the realities of mass production are accounted for.
(By the way, genetic drugs do have a 20% tolerance rate while brand name is much more close to the actual dose). While this is ok for Penicilin if you use a drug like lithium and the dose is off you will have severe side effects.

It could be BMW has a very tight tolerance requires for these engines and the manufacturing process was not good enough and a certain percentage came out too big.

In this scenario only a small percentage would have the problem.

It's also important to look at the Porsche IMS issue. It's only 1-10% of those that actually had a problem. I wouldn't say everyone that bought a Porsche from 97-07 needed to have the IMS replaced.

Of course the last hypothesis is the one everyone believes, with in my opinion, less evidence supporting it than the others I listed, which is all S85/S65 engines constantly wear the bearings and they must be replaced every 50-80k miles. If this was the case I think the issue would be as big or bigger as IMS and BMW would have been forced to issue a recall or statement, and we would have seen a lawsuit emerge. You know Lawyers would love to get millions from BMW in a slam dunk case like bad engines. They couldn't do it and deemed it not worthy of their time in a world where they take dozens of cases with low success rates hoping for one home run.

If the bearings are actually wearing because they are too big, at some point they may shrink to the appropriate size and not wear anymore. Pulling a bearing and taking a picture of exposed copper isn't proof of concept. It could have done that at the first 10k miles and been a happy bearing for 50k more as it's tolerance has worn to an acceptable size.

Bottom line is, we don't know all this is speculation of a rare problem

[tdott]

Originally Posted by SleepingBMW

Bottom line is, we don't know all this is speculation of a rare problem

Yes we do know, it's the newbies that keep asking the same dumb questions people are tired of answering.

It is not related to warm up or treatment of the engine tracking/etc. There have been owner testaments to it over the years, including when these cars were still under warranty.

Thinking an s65 bearing is somehow special and sound tested logic/knowledge from the past 30+ years of engine building doesn't apply to it, is. just. stupid. and a clear indication that person doesn't know what they are talking about and probably never seen the inside of an engine irl.

There is enough evidence out to draw logical conclusions that of the options available on the market today, an OEM bearing is the least best choice (aka worse choice) and has zero chance of resolving a bearing wear problem even if you don't believe there is a clearance issue which there is clear evidence of.

[Ab28]

Originally Posted by IamFODI

Right. But given the variables involved, bearing pics from a few engines with 30k-40k amounts to basically nothing. When we have comprehensive info on several dozen engines with like 80k+, then it'll be time to talk.

Slight disagreement here as plenty of low mileage engines with factory bearings came out looking bad.

I replaced my bearings at 33k and they were VERY worn considering the mileage. If there are aftermarket bearings being pulled at around the same mileage without wear, I would say with certainty that it amounts to more than nothing. Still not enough data to prove a point beyond doubt, but it's something.

If one believes the issue could also be from cold starts and warmup procedure, and not just clearances, going OEM isn't the worst idea. The problem is we don't know this.

I think the safest bet is to go with an increased clearance bearing and baby the car until operating temp. This combo allows for both major theories to be dealt with at the same time.

[pbonsalb]

If you study the pictures of rod bearings sets that come out of S65 and S85, you will find that most look excessively worn compared to bearings from other motors with the same or more miles. I would feel better about leaving what seems to be well enough alone if most bearing sets that came out looked at least average. I changed mine in 2014. They were prematurely worn, but not as bad as some.

[Bartledoo]

Originally Posted by SleepingBMW

... And by the way I don't think you get any extra power past 7.5k anyway.

I'm going to just ignore most of the dumb shit you said, and ask have you ever even seen an S65 dyno? Also, who at a dealership has actual technical expertise regarding this matter, and assuming they knew about the issue (we'll say this is hypothetical for you) why would a dealership recommend that you preventatively change the bearings and admit to the issue?

[pbonsalb]

He has an S85.

[Big boi m5]

I have an s85.

My main question is still: will the rod bearing replacement show up in a car fax?

Also, I'm not stating the dealer is the authority here, but I'm also not assuming they are a uniform homogenous corporate actor out to trick customers into blowing up engines in order to protect BMW from accusations of designing bad engines.

BMW isn't that smart and they're not that stupid either.

The guy at The service counter just gave his thoughts when I asked him. I'm not saying believe him or not just putting that Information out there and following it up by saying it's all just speculation. Not sure why so angry about it.

I'm really just wanting to know if it shows up in the carfax though

[Ab28]

Originally Posted by SleepingBMW

My main question is still: will the rod bearing replacement show up in a car fax?

I'm really just wanting to know if it shows up in the carfax though

If you do it at any independent shop it shouldn't show up.

Cant comment on this if it's done at the dealer (but why in the world would you ever have it done there)

It doesn't really matter if it does show up. The car either has documentation to prove they were changed or not.