Do all E9x M3 have rod bearing problems?

[MaximusB]

So I am new to the forum, but for the last couple of weeks I've came across quite a few threads related to rod bearing issues. Is the issue sort of got blown out of proportion or all e9x m3 regardless of production year have this problem? If it is really that common then couldn't owners have the dealer fix it under warranty?

[roastbeef]

no. there are two track guys with 25+ track days on original bearings. one is superchargarged, and one is n/a, but the n/a car has about 125k miles. so i'd say no, they don't all have problems.

[vsix]

Welcome to the forum
It's an issue that occurs on S65 engines, thats why there is an cheap fix.
Cheap if compared to the costs of swapping an engine.
We usually get our rod bearings replaced, we got alot of good aftermarket vendors that do these type of things.
Hope I could help.

[pbonsalb]

Originally Posted by MaximusB

So I am new to the forum, but for the last couple of weeks I've came across quite a few threads related to rod bearing issues. Is the issue sort of got blown out of proportion or all e9x m3 regardless of production year have this problem? If it is really that common then couldn't owners have the dealer fix it under warranty?

Unfortunately, failures have occurred in varying model years, with varying driving styles or use, with varying miles, and with varying maintenance. The only good news is that so far only a small percentage of motors have failed. But there is no certain simple test to determine whether yours is fine. As someone who does not take expensive risks, I recommend including the money for a bearing change into your purchase budget.

[Sephiroth]

Here is some useful information. Keep in mind these guys do sell replacement bearings, it is for you to decide if they have an agenda or not.
http://www.bebearings.com/Overview.html

[tadmcmichael]

There are no definitive numbers, but failure rate seems to be about 1% (arguably). I think you would be a lot less likely to have an issue if you purchased a car with at least twice as many oil changes as BMW recommends. I also run 0W 40 Mobil 1 because one theory is that the stock molasses thick oil doesn't flow well into the too tight tolerances of the rod bearings. Some of the oil analysis supports this with decreased levels of rod bearing metals with the Mobil 1.

There is something to be said for changing out the rod bearings as preventative maintenance if the car has a boatload of miles. However for the rest of the cars out there, I don't see that changing these out with after market solutions solves anything. I haven't seen evidence that these "new" rod bearings/bolts are any better than what BMW put in the car. Seems like the money people spend on a prophylactic bearing swap would be much better spent on an extended warranty. Especially a warranty that would cover the throttle actuators, which is a far more likely failure in these cars.

[Sephiroth]

Originally Posted by tadmcmichael

There are no definitive numbers, but failure rate seems to be about 1% (arguably). I think you would be a lot less likely to have an issue if you purchased a car with at least twice as many oil changes as BMW recommends. I also run 0W 40 Mobil 1 because one theory is that the stock molasses thick oil doesn't flow well into the too tight tolerances of the rod bearings. Some of the oil analysis supports this with decreased levels of rod bearing metals with the Mobil 1.

There is something to be said for changing out the rod bearings as preventative maintenance if the car has a boatload of miles. However for the rest of the cars out there, I don't see that changing these out with after market solutions solves anything. I haven't seen evidence that these "new" rod bearings/bolts are any better than what BMW put in the car. Seems like the money people spend on a prophylactic bearing swap would be much better spent on an extended warranty. Especially a warranty that would cover the throttle actuators, which is a far more likely failure in these cars.

Absolutely untrue. If you believe the issue to be of clearance, as you said, then mileage is irrelevant. Bad clearance can and has affected low mileage cars.

[tasho_x2]

I do belive this issue is more uncommon than it seems. Reason being, everybody that has the issue posts about it. If everybody that never had the issue posed about not having it, the posts about the issue occurring would be unnoticeable. Same issue with the AMG M156 engine (6.2L V8) and head bolt problem. I have many friends that have vehicles with those engines and have modified their cars heavily and never had the head bolt issue.

I would not worry about the rod bearing issue.

[MaximusB]

What new bearings do guys use if the BMW ones have issue with clearance? Do aftermarket bearings have more tolerance?

I guess one thing I'm confused about if the oem bearing have clearance issue then how would anyone know what size of bearings to get without measuring their crank and rod size.

[serranot]

Originally Posted by MaximusB

What new bearings do guys use if the BMW ones have issue with clearance? Do aftermarket bearings have more tolerance?

I guess one thing I'm confused about if the oem bearing have clearance issue then how would anyone know what size of bearings to get without measuring their crank and rod size.

A couple of the folks on here did exhaustive measurements of the cranks and rods and then spec'ed new bearings with increased clearance. The variance in the cars is very good, and even BMW does not spec multiple sizes. So unless you do a custom order, most take a chance with stock or buy aftermarket. I went with BE and OEM rod bolts.

You will get differences of opinion. I bought them and replaced them with only 25K on the motor. I'm out of warranty and am not a "don't fix it unless it's broke" person anyway.

[///M Power-Belgium]

The OP question is actually useless...
Because...

Meanwhile (the last 2 years) we saw enough pulled S65 bearings on BP .
And we saw what ?
Proof that 90 % of the pulled bearings showed premature wear .
And let's not forget about this => http://www.m3post.com/forums/showthread.php?t=786615

So yes....."Houston we have a problem"

[mxa121]

It is safe to say:

All S65 engines experience rod bearing wear.
Not all S65 engines fail due to rod bearing wear.

If the M3 is a car you want to buy, drive hard, and keep, it would be a wise investment to have them swapped at some interval. The interval depends on the car's prior use, modifications, and proposed use.
(i.e. track rat supercharged, do it now and every 40k. or daily cruiser, maybe every 80k)

On a 2008-2010 M3, you can track bearing wear by getting oil analysis done at each change. You can see the lead content (bearing material). Excessively high lead content would mean pull the bearings. Low content, probably OK. That's what I did.

[MFL]

Schrodinger's Rod Bearings...

[Rajmun340]

Originally Posted by MaximusB

So I am new to the forum, but for the last couple of weeks I've came across quite a few threads related to rod bearing issues. Is the issue sort of got blown out of proportion or all e9x m3 regardless of production year have this problem? If it is really that common then couldn't owners have the dealer fix it under warranty?

Don't read into the fear-mongers posts above, some individual here are well known to have agitated this issue over the years far beyond what it is. I don't need to identify them, it is evident from the concerned posts. The only solid objective information you can count on is that less than <1% engines have failed from rod bearing failure and that it has not correlated with miles or even tracking. Everything else is subjective interpretations and inconclusive. Period.-

Clearance is only one several proposed theory that is not well accepted and was solely pushed by the same small group of people that have used it as moto to sell rebranded clevite bearings batches (rebranded "BE" bearings).

Nobody has ever been able to correlate the failure to a specific cause (outside BMW). But each and every S65 engine assembled at BMW got its crank journals and bearings measured and logged into confidential manufacturer data logs (take my word for it). Therefore BMW has all the information it needed all along to trace back and correlate to failed engine. They have not changed dimension specs of the OEM bearings (only materials) which invalidates the clearance theory.

Interpretation of pictures of pulled bearings is completely subjective, it depends on who you ask. The deleterious fearmonger will make wild assertions assimilating any wear to a latent case and base their fallacious % on that. Completely frivolous.

There is no evidence to support that replacing bearings has prevented or will prevent this rare failure. But if you believe it, you may decide to spend money for that.

There is no evidence that increased oil changes has prevented etc.. Sure it will not hurt and cleaner oil is always good. You decide.

Another theory is that the issue is chemical not simply dimension tolerances. There was one flagrant case of pulled OEM bearings with visible wear then replaced with Callico coated OEM bearings and ARP bolts and the engine supercharged, pulled again tens thousands miles later and it had no visible wear. (This is the best coating available, and is superior to BE's clevite coating).

In conclusion, you can do nothing which i think is perfectly fine. If you decide to change bearings i would get OEM bearings and have them Callico coated.

[FogCityM3]

Not to mention, there was a time when it seemed like every week there was a new failure. The failure rate reported on this site seems to be decreasing from the initial reports. Could be a survivorship bias issue that if engine hasn't had problems beyond a certain mileage threshold it is probably ok.

To the OP: There is no conclusive evidence of what causes these issues, but tolerance stack seems to be the prevailing theory, which while certainly possible, would seem like a glaring misstep by a company that is very engineering focused and assembled the S65 and S85 engines by hand. Other theories have focused on ethanol in fuel, improper driving habits (warm up and lugging the engine), an ionic knock control system that may not be capturing all detonation and pre-detonation, tuned and supercharged engines, and lower fuel octane.

Personally, I think the most plausible explanation lies in the S65 vs most other engines as the way to properly drive one is quite different from most out there. Being a high-revving motor with a high compression ratio that really needs 93 octane to run, can be very sensitive to poor driving habits including improper warm-up and using too high a gear while accelerating (lugging the engine). Peak torque occurs fairly early (for the rev range) around 3,900 rpm, and even with the stock cold start rev control, the limit is 4,500 rpm and when the oil reaches 172 degrees F, you are allowed the full rev range (normal operating temp for oil should be about 200 degrees) and if you are using too high a gear around/near the peak torque, when oil isn't completely warmed up, on a less then optimal octane (91) it is putting a lot of pressure on the cylinders and hence the bearings. Also with such tight tolerances, there is probably not enough room for error. Personally, would be less worried about the clearance that BMW chose vs getting bearings that have a stronger/smoother coating that improves effective viscosity lower in the rev range and prevents seizure.

Originally Posted by tasho3

I do belive this issue is more uncommon than it seems. Reason being, everybody that has the issue posts about it. If everybody that never had the issue posed about not having it, the posts about the issue occurring would be unnoticeable. Same issue with the AMG M156 engine (6.2L V8) and head bolt problem. I have many friends that have vehicles with those engines and have modified their cars heavily and never had the head bolt issue.

I would not worry about the rod bearing issue.

[Helmsman]

Originally Posted by mxa121

It is safe to say:

All S65 engines experience rod bearing wear.
Not all S65 engines fail due to rod bearing wear.

If the M3 is a car you want to buy, drive hard, and keep, it would be a wise investment to have them swapped at some interval. The interval depends on the car's prior use, modifications, and proposed use.
(i.e. track rat supercharged, do it now and every 40k. or daily cruiser, maybe every 80k)

On a 2008-2010 M3, you can track bearing wear by getting oil analysis done at each change. You can see the lead content (bearing material). Excessively high lead content would mean pull the bearings. Low content, probably OK. That's what I did.

Claiming that ALL S65 engines wear their bearings is clearly not true, we have seen high mileage bearings come out fine. What is a fact however is that the absolute majority of the 65.000 produced S65' continue to run strong as we speak.

Also fact is that some engines certainly experience bearing wear, reasons for this being debated, such as lack of maintenance, poor warm up, tolerance stack up, tight bearing clearance, maybe in combination.
So yes some experience issues but FAR from all.

[Doc Oc]

Originally Posted by FogCityM3

Not to mention, there was a time when it seemed like every week there was a new failure. The failure rate reported on this site seems to be decreasing from the initial reports. Could be a survivorship bias issue that if engine hasn't had problems beyond a certain mileage threshold it is probably ok.

To the OP: There is no conclusive evidence of what causes these issues, but tolerance stack seems to be the prevailing theory, which while certainly possible, would seem like a glaring misstep by a company that is very engineering focused and assembled the S65 and S85 engines by hand. Other theories have focused on ethanol in fuel, improper driving habits (warm up and lugging the engine), an ionic knock control system that may not be capturing all detonation and pre-detonation, tuned and supercharged engines, and lower fuel octane.

Personally, I think the most plausible explanation lies in the S65 vs most other engines as the way to properly drive one is quite different from most out there. Being a high-revving motor with a high compression ratio that really needs 93 octane to run, can be very sensitive to poor driving habits including improper warm-up and using too high a gear while accelerating (lugging the engine). Peak torque occurs fairly early (for the rev range) around 3,900 rpm, and even with the stock cold start rev control, the limit is 4,500 rpm and when the oil reaches 172 degrees F, you are allowed the full rev range (normal operating temp for oil should be about 200 degrees) and if you are using too high a gear around/near the peak torque, when oil isn't completely warmed up, on a less then optimal octane (91) it is putting a lot of pressure on the cylinders and hence the bearings. Also with such tight tolerances, there is probably not enough room for error. Personally, would be less worried about the clearance that BMW chose vs getting bearings that have a stronger/smoother coating that improves effective viscosity lower in the rev range and prevents seizure.

Good post. I've often wondered how much lugging the engine affects the bearings. I've noticed if I put it in D the car will be in 6th or even 7th gear by 35 mph and seems to be trying to keep the revs as low as possible for fuel economies sake, but the vibrations seem pretty bad in that low rpm range and the car doesn't seem mechanically happy below 2k rpm....but still wants to spend most of its time there. Those vibrations seem especially bad when the engine is cold which, combined with a thick, cool oil seems like a bad combo.

[loveskiing]

I use to not give rod bearings a second thought...then I spoke to a really knowledgeable senior member of this forum who lives in San Francisco, and he recommended that I change the rod bearings every time I refueled...
I wondered if that wasn't a little too excessive since I don't race or track the car. He thought about it for a moment and we both agreed that I would only change the rod bearings when I changed the oil. His advice was spot on because I'm at 30k, have only changed the rod bearings three times and it must be working because I haven't had any rod bearing issues!

[Dan Bilzerian]

Originally Posted by MFL

Schrodinger's Rod Bearings...

Are you into physics??

[admranger]

Originally Posted by MFL

Schrodinger's Rod Bearings...

Nice!

[cmo_93]

No.

[serranot]

Originally Posted by MFL

Schrodinger's Rod Bearings...