Cumulative data on S65 engine failures.

[regular guy]

Originally Posted by BossManE90

So, is there an installation difference with ARP studs, or something else recommended?

You mean ARP bolts, not studs? Yes.

I don't have clamping force of the ARP-2000 or ARP-625, but I do have it for some near-equivalent Carrillo rod bolt counterparts.

http://www.m3post.com/forums/showpos...postcount=2550

The OEM bolts are 20-Nm + 130 degrees. ARP-2000 are 45-ft/lbs. ARP-625 are 60-ft/lbs. But the ARP-2000's have as much as 0.001 inch deformity at 90-degrees over OEM rod bolts; and ARP-625's much less, but still some. I'll post the data in a new thread when I get some time...been far too busy these days, and backed up on a bunch of guys wanting stuff in the dyno database too.

[BzsBimmer]

Originally Posted by BossManE90

So, is there an installation difference with ARP studs, or something else recommended?

Iirc Regular Guy (or someone else) was recommending that BMW factory bolts used. I'd have to dig up the thread/post to be sure.

Edit he beat me to it lol

[08 E92 Jerez Black]

Bossmane90. I went round and round on that one. The best response I got was if you are not adding a supercharger or doubling the horsepower in some other way you will be fine with the stock ones. I replaced mine with new stock ones. If you go ARP you really should pull the motor and line bore the rods to be sure they aren't out of round. Might as well not add a problem while fixing one I say

[regular guy]

Originally Posted by 08 E92 Jerez Black

Bossmane90. I went round and round on that one. The best response I got was if you are not adding a supercharger or doubling the horsepower in some other way you will be fine with the stock ones. I replaced mine with new stock ones. If you go ARP you really should pull the motor and line bore the rods to be sure they aren't out of round. Might as well not add a problem while fixing one I say

+1

I just helped a guy out of a jamb with a blown motor. Long story short, he was buying spare parts from me, but then shipped ARP-625 rod bolts to me along with bearings. We were going to size the crank to the rods. But when we measured the rod journal clearance, it came out right where we wanted without adjusting the journal size. That's exactly when we also discovered the rod bore distortion with the ARP rod bolts. So we backtracked with Van Dyne Engineering and found that they had align-bored the rod big end with the new ARP bolts, just as any good shop would do. So we got the best of all worlds. We didn't have to adjust the crank journal size; we used the better rod bolts; and we got the bearing clearance we wanted without any rod bore distortion.

EDIT: I meant to say "honed the rod big end" ... not "align-bored the rod big end." I know the difference.

[Pro-AM3]

Originally Posted by regular guy

+1

I just helped a guy out of a jamb with a blown motor. Long story short, he was buying spare parts from me, but then shipped ARP-625 rod bolts to me along with bearings. We were going to size the crank to the rods. But when we measured the rod journal clearance, it came out right where we wanted without adjusting the journal size. That's exactly when we also discovered the rod bore distortion with the ARP rod bolts. So we backtracked with Van Dyne Engineering and found that they had align-bored the rod big end with the new ARP bolts, just as any good shop would do. So we got the best of all worlds. We didn't have to adjust the crank journal size; we used the better rod bolts; and we got the bearing clearance we wanted without and rod bore distortion.

Nice, i was abotu to ask about the Carillo stuff. Im probably going to do it all at once, pulle motor, ARH rods pistons etc at one time.

*edit

How often is this list of failures updated?

[crypticc]

Originally Posted by SenorFunkyPants

The above is for USA/Can cars without superchargers.
The "average mileage at engine failure in production year" green line is pretty much as expected.
The "number of cars produced in year divided by the number of failures" purple line however is not. It should follow the green line to show that newer cars are less likely to fail but clearly doesn't.
Currently of the 47 entries:
22 are 2007/8/9/10 cars from a total production of 15203 cars @ an ave miles at failure of 61,500.
25 are 2011/12/13 cars from a total production of 15053 cars @ an ave miles at failure of 25,800.
The change in rod bearing spec occurred sometime around July/Aug 2010 (probably for the 2011 MY)

Work with me on a though experiment for a moment...

Let's say the effect of anything that normally fails over time due to cause A +B.

Now let's say cause A (bearing clearance issue) is proportional to usage (mileage or load experienced).
and let's say cause B (normal manufacturing tolerance) is catastrophic regardless of mileage and could be considered unlucky.

<2010
If you look at older models A failures would out weigh B, so your average mileage per failure would be high. Your graph shows this.

>2010
Now imagine newer cars where A had been fixed. But some poor owners still have problem B which is just the luck of the draw.

You'd be left with the true dodgy builds in B. those ones that would have failed at small miles whatever the state of the bearings. That would mean your average miles per failure would drop. Your graph shows this.

I'm not saying this is what is occurring.
I guess what I'm saying is that now you could be seeing failure rate due to an assembly issue or some other problem not being fixed, but that a more general concern proportional to mileage and load on the engine had been fixed and that could be the bearing issue.

The upside is that >MY 2010 problem now doesn't seem related to mileage, so either you'll blow up, probably quite early, or you probably will not at all.

A concern about this is that eventually those in the <2010 engines will begin to move up the curve as they put on more miles and become more likely to fail as time and mileage increases.

[SenorFunkyPants]

Originally Posted by crypticc

The upside is that >MY 2010 problem now doesn't seem related to mileage, so either you'll blow up, probably quite early, or you probably will not at all.

A concern about this is that eventually those in the <2010 engines will begin to move up the curve as they put on more miles and become more likely to fail as time and mileage increases.

Fair comment...what do you think of the graph below?




I think this shows the effect far clearer. This graph is of all failures except supercharged cars.
The X axis is stated year of manufacturer, oldest at zero (ordered by date of fail).
There was the bearing spec change to EU mandated lead free bearing at around mid 2010 most likely for the 2011 model change in August 2010.
Assuming all cars with a stated build date of 2011 have the new bearings then the change occurs on the graph with car 26.

I think its obvious that the bearing change had a significant effect on the mileage at which cars failed. The new 2011 bearings originally measured up with a slightly larger clearance than the old bearings which is somewhat surprising given the result.

[SenorFunkyPants]

Originally Posted by BossManE90

How often is this list of failures updated?

Its up date regarding failures reported on m3post by their owners as best I know.

[SenorFunkyPants]

Originally Posted by 08 E92 Jerez Black

Is there anyone working this that is gathering specs from rod bearings pulled out of engines?
Attachment 1194833

Not as far as I know...it is always interesting to see pictures of removed bearings as it helps to build a better picture. I would suggest yours are in line with DIY bearings pulled by other m3posters, which is in generally better condition than those shop pulled.
Unless the bearing surface shows the copper layer then there is no imminent threat of engine failure (from that part).

[Rich150001]

Tried searching, but couldn't find an answer.

Are the rod bearings something that will need to be checked every oil change or inspected every x number of miles even after upgrading/changing the rod bearings? Do the upgraded/coated rod bearing make them prone to failure for the life of the vehicle?

[SenorFunkyPants]

Originally Posted by Rich150001

Are the rod bearings something that will need to be checked every oil change or inspected every x number of miles even after upgrading/changing the rod bearings? Do the upgraded/coated rod bearing make them prone to failure for the life of the vehicle?

I don't think anyone knows for sure.
If you have a 2007-2010 car, then it came from the factory with a lead faced bearing. If you changed those bearings at say 80K miles using bearings with the same spec (lead faced and the same clearance), then logically they should be good for another 80K miles all else being equal.
That would be my choice...change the bearings at a reasonable mileage using the nearest equivalent to the old (pre 2011) OEM spec bearing for material and clearance...at least if you replace like for like you know where you are.
I guess if the bearings are coated then that would be better as long as the clearance remained similar to OEM.

[crypticc]

Originally Posted by SenorFunkyPants

Fair comment...what do you think of the graph below?




I think this shows the effect far clearer. This graph is of all failures except supercharged cars.
The X axis is stated year of manufacturer, oldest at zero (ordered by date of fail).
There was the bearing spec change to EU mandated lead free bearing at around mid 2010 most likely for the 2011 model change in August 2010.
Assuming all cars with a stated build date of 2011 have the new bearings then the change occurs on the graph with car 26.

I think its obvious that the bearing change had a significant effect on the mileage at which cars failed. The new 2011 bearings originally measured up with a slightly larger clearance than the old bearings which is somewhat surprising given the result.

I looked at number of cars produced vs number of failure (higher is better). Although quantity is low so not necessarily statistically significant the jump inmplies quality or something was fixed; and then it is reasonable to think that the failure remaining could be either a different cause or just a manufacturing tolerance/luck of the draw leading to early failure. Those early fails might still be in the <2010 figures, just hidden by the greater cause ( bearing design) and takes slightly longer to reveal.

[08 E92 Jerez Black]

The Coated bearings made me a bit nervous, since that would imply changing the clearance in some way to account for the coating, weather that would be thinning the bearing out or just making it a tighter clearance, I got the treated ones from Bimmerworld which are stock BMW bearings (part numbers 11 24 7 841 702 and 11 24 7 841 703) that are treated, not coated. My best friend uses bearings that are treated in the same process in his e46 M3 that he races and has had great luck with them, in his words they are bullet proof. Here is a video I saw when looking into which bearings I was going to use in the install I just finished. Not the exact company that Bimmerworld uses as far as I know but the same process.

[Rich150001]

Originally Posted by SenorFunkyPants

I don't think anyone knows for sure.
If you have a 2007-2010 car, then it came from the factory with a lead faced bearing. If you changed those bearings at say 80K miles using bearings with the same spec (lead faced and the same clearance), then logically they should be good for another 80K miles all else being equal.
That would be my choice...change the bearings at a reasonable mileage using the nearest equivalent to the old (pre 2011) OEM spec bearing for material and clearance...at least if you replace like for like you know where you are.
I guess if the bearings are coated then that would be better as long as the clearance remained similar to OEM.

Thanks, I'll continue to monitor the forums and I guess time will tell. This issue is the only reason I'm considering a warranty right now. Would hate to shell out money for a new engine.

[Rich150001]

Originally Posted by crypticc

I looked at number of cars produced vs number of failure (higher is better). Although quantity is low so not necessarily statistically significant the jump inmplies quality or something was fixed; and then it is reasonable to think that the failure remaining could be either a different cause or just a manufacturing tolerance/luck of the draw leading to early failure. Those early fails might still be in the <2010 figures, just hidden by the greater cause ( bearing design) and takes slightly longer to reveal.

Would be interesting to see the actual numbers from BMW.

[08 E92 Jerez Black]

The warranty option seems kind of hit or miss to me, unless it is the Factory BMW one, you have no guarantee that a warranty company wouldn't pull the abuse card and not cover the repair. I guess it all depends on how you drive as well. I bought this car to drive it hard, so I do maintenance and upgrades accordingly. Giving it all the necessary love it needs to give me performance back.

[SenorFunkyPants]

I have a BMW warranty so I'm expecting that they will cover any problem I have.
It is hard to decide whether to change the rod bearings or not....I guess it depends on a mixture of how you use the car and your own level of paranoia.
A rough estimate of the failure rate is around 1 to 1.5% worldwide.
If you are beating on your car pretty hard then a change makes sense, if you are more of a highway and cruising kind of guy then perhaps not.

[08 E92 Jerez Black]

Agreed!

[///M Power-Belgium]

Originally Posted by 08 E92 Jerez Black

The Coated bearings made me a bit nervous, since that would imply changing the clearance in some way to account for the coating, weather that would be thinning the bearing out or just making it a tighter clearance, I got the treated ones from Bimmerworld which are stock BMW bearings (part numbers 11 24 7 841 702 and 11 24 7 841 703) that are treated, not coated. My best friend uses bearings that are treated in the same process in his e46 M3 that he races and has had great luck with them, in his words they are bullet proof. Here is a video I saw when looking into which bearings I was going to use in the install I just finished. Not the exact company that Bimmerworld uses as far as I know but the same process.

Jaw dropped when I saw the difference !
But how is it acting with high temp. conditions ?

[08 E92 Jerez Black]

So far all is good, I definitely noticed a difference, so much less noise on cold starts as well

[swamp2]

Originally Posted by 08 E92 Jerez Black

More snake oil... What does this have to do with operating environment of a crankshaft bearing? Nothing. Furthermore I suspect the physics here has more to due with air than anything else. Anyone who has played with very flat surfaces (i.e. ground and polished) knows that they can easily create a vacuum between them pretty well bonding the parts.

I've not seen a speck of real hard evidence as to the benefits of WPC treatment of crank bearings, at their website or in response to questions posed here. Now this being said, it is well known that various work hardening/peening surface treatments can provide beneficial changes to the mechanical properties of metal surfaces.

[Merlin_83]

Originally Posted by Irishace

So basically an average of just around .003% of S65s fail. Of those that failed, just over 25% were supercharged and 36% of those that failed were 'modified'.

Great data here so far, now lets continue to panic about the rod bearing epidemic that plagues .003% of owners!

THIS !!