Official S65 Rod Bearing Condition Example Thread

DCT M3 102K
My car was about to die .
swapped them with be bearing with apr bolts

AndriTheGiant wrote

DCT M3 102K
My car was about to die .
swapped them with be bearing with apr bolts

Good catch!!

That is a lot of copper showing for sure!!

Wow! You definitely dodged a bullet there!

What made you decide to change them? Oil report? New owner & decided it was a good idea? Funny noises?
Btw, welcome to the forum

Recently picked up my 4th E92 M3, this time with higher mileage but it was looked after by PO. Took it to deansbimmer MPORIUM for RB service, here is the result:

Assimilator1 wrote

Yea the alu bearings usually come out looking like that, including the wavy pattern.
Apparently it's down to the way the babbitt layer is applied.

Interesting, I recall seeing similar wear patterns on higher milage cars. I haven't visually inspected them but I did see some uneven surfaces on a few of the lower bearings.

russiamutha
Not bad those shells for a 99k S65.

Scharbag wrote

Plastigauge is meaningless. Plain and simple.

.....

Cheers,

Going back to this point, as I don't think it was answered.
I'm getting mixed info on this, on the one hand I'm hearing it'll give you a decent ball park figure, & yet other people are saying it's pointless.

I shall be replacing the bearings on my M3 within the next 2 months, should I bother with plastigauges?

Assimilator1 wrote

russiamutha
Not bad those shells for a 99k S65.



Going back to this point, as I don't think it was answered.
I'm getting mixed info on this, on the one hand I'm hearing it'll give you a decent ball park figure, & yet other people are saying it's pointless.

I shall be replacing the bearings on my M3 within the next 2 months, should I bother with plastigauges?

Not a ball park, you can get very accurate measurements with plastigauge.

Pointless because there's not much you can do unless you remove your crankshaft to get journals polished or a replacement bearings set. Depends whether you trust your bearing manufacturer to get your clearances right. But what harm could it do other than providing you with more information to make an informed choice?

Good to hear , have you used & compared plastigauges to other ways of measuring?

Not entirely pointless for me, I think lol. I have a micrometer (hopefully good enough!) & I intend to measure the shells as per Deansbimmer recommendations. I figure if I find a bearing with noticeably tight clearances (via plastigauges) I could put the skinniest shells with the fattest journal , oh & hope that'll be enough, otherwise, like you said, without more drastic work I'm stuck with what I've got.

Deansbimmer
Regarding measuring shells, my metric micrometer goes down to 2 decimal places (0.xx incase I've described it wrong), will that be enough to measure shells accurately?

Assimilator1 wrote

russiamutha
Not bad those shells for a 99k S65.

Scharbag wrote

Plastigauge is meaningless. Plain and simple.

.....

Cheers,

Going back to this point, as I don't think it was answered.
I'm getting mixed info on this, on the one hand I'm hearing it'll give you a decent ball park figure, & yet other people are saying it's pointless.

I shall be replacing the bearings on my M3 within the next 2 months, should I bother with plastigauges?

Plastigauge is only really useful as a sober second thought. It will let you know if you are super tight/loose. It only returns a ballpark. And it can be inconsistent and easily affected by improper use. It also can expire due to age.

But as has been said, unless you disassemble your engine, plastigauge is your only choice to confirm nothing is really wrong.

Assimilator1 wrote

Good to hear , have you used & compared plastigauges to other ways of measuring?

Not entirely pointless for me, I think lol. I have a micrometer (hopefully good enough!) & I intend to measure the shells as per Deansbimmer recommendations. I figure if I find a bearing with noticeably tight clearances (via plastigauges) I could put the skinniest shells with the fattest journal , oh & hope that'll be enough, otherwise, like you said, without more drastic work I'm stuck with what I've got.

Deansbimmer
Regarding measuring shells, my metric micrometer goes down to 2 decimal places (0.xx incase I've described it wrong), will that be enough to measure shells accurately?

No, .xxmm won't get you anywhere with bearings. Some relatively inexpensive starrett, SPI, or Mitutoyo micrometers (must have a ball anvil) have resolution to .001mm. Plastigage is OK but not consistent, and has been shown to be off by as much as .002x. It's use is ok to see if you're in the ballpark but not to use during an attempt to make changes to clearances.

Assimilator1 wrote

Not entirely pointless for me, I think lol. I have a micrometer (hopefully good enough!) & I intend to measure the shells as per Deansbimmer recommendations. I figure if I find a bearing with noticeably tight clearances (via plastigauges) I could put the skinniest shells with the fattest journal , oh & hope that'll be enough, otherwise, like you said, without more drastic work I'm stuck with what I've got.

Deansbimmer
Regarding measuring shells, my metric micrometer goes down to 2 decimal places (0.xx incase I've described it wrong), will that be enough to measure shells accurately?

You'll get more accurate measurements with a micrometer and a dial bore gauge no doubt, but that wont be possible with a replacement through the sump. I would think you'd want to check clearance between the housed bearings with the crank journal, not just checking shell thickness. Plastigauge is really the only way to do that, and is an industry accepted method, and even built into the ISTA workshop manual for rod bearing replacements. I mean you can just assume theres too much error in the measurement, but really isnt it better than going in blind? If it was me and I got an off measurement, I'd be taking the engine out and sending it to a machine shop to look at.

You can pretty accurate measurements from plastigauge, but a tool is only good as the person behind it.

I would not worry if the shells are verified by you or the seller, the motor has not suffered a spun bearing or rod knock or locked up such that you are changing bearings as preventative maintenance, and you find no surprises when doing the job that suggest the crank could be damaged or out of spec (and if it was out of spec enough, you would be in the first category of spun bearing, rod knock or lock up).

We are not building an engine. Just changing a part. If the engine is fine and the part within spec, you can just install it. I am not going to pull my motor and disassemble the bottom end just because the bearings have wear. However, I might pull the motor and disassemble the bottom end to change the main bearings preventatively if I decide I need a project sometime (I changed the rod bearings myself in 2014, but that was only 42k miles ago and the car has only 102k total so I am not sure when I will prioritize that project).

Ok thanks guys, think I'll stick to plastigauge to make sure clearances are in range.
I'll look into to getting a new micrometer to measure the shells & keep the variance from them to a minimum, & to put the thickest shells on top (assuming I don't buy a pre-mixed, measured & marked set from someone).

(further input still welcomed btw ).

Scharbag wrote

AndriTheGiant wrote

DCT M3 102K
My car was about to die .
swapped them with be bearing with apr bolts

Good catch!!

That is a lot of copper showing for sure!!

Scharbag wrote

AndriTheGiant wrote

DCT M3 102K
My car was about to die .
swapped them with be bearing with apr bolts

Good catch!!

That is a lot of copper showing for sure!!

Right caught just in time .

Assimilator1 wrote

Wow! You definitely dodged a bullet there!

What made you decide to change them? Oil report? New owner & decided it was a good idea? Funny noises?
Btw, welcome to the forum

Scharbag wrote

AndriTheGiant wrote

DCT M3 102K
My car was about to die .
swapped them with be bearing with apr bolts

Good catch!!

That is a lot of copper showing for sure!!

Assimilator1 wrote

Wow! You definitely dodged a bullet there!

What made you decide to change them? Oil report? New owner & decided it was a good idea? Funny noises?
Btw, welcome to the forum

Just for peace of mind , I bought the car with high mileage so I thought it would be a very good idea to swap them out and no I didn't hear any noises .

Hi all,

Glad to offer my first contribution to the thread. My car is a 2011.75, and swapping for BE Bearings and ARP bolts at 75K miles is just part of the regular maintenance schedule, as far as I'm concerned. I also had them swap in new OEM motor mounts as preventative maintenance while they were in there, and have definitely noticed less NVH afterwards. The stock ones were not leaking yet but were pretty much finished.

Thanks to Eurowise in Charlotte, for doing a great job!

I feel like the pic shows that I'm doing the right thing with my easy warm-up, low-rev routine and 5K changes with Liqui-Moly Synthetic 10W-60.

At last analysis for these bearings, Blackstone had reported: "This is the least amount of metal to come out of this engine so far. There's just 2 ppm aluminum, and iron is in great shape at 9 ppm. Your BMW is wearing well for the type, and shows no signs of poor bearing wear, or any other issues for that matter. Insolubles tested at just a trace level, so oil filtration is working well, and there's no contamination in the sample. You're taking great care of this M3!".

Future Blackstone reports will establish a new bearing material baseline for this S65, but that's two oil changes away because I plan the first change to occur at just 2K miles so we can cut open the filter to check for anything unusual.

cognoscenti wrote

Hi all,

Glad to offer my first contribution to the thread. My car is a 2011.75, and swapping for BE Bearings and ARP bolts at 75K miles is just part of the regular maintenance schedule, as far as I'm concerned. I also had them swap in new OEM motor mounts as preventative maintenance while they were in there, and have definitely noticed less NVH afterwards. The stock ones were not leaking yet but were pretty much finished.

Thanks to Eurowise in Charlotte, for doing a great job!

I feel like the pic shows that I'm doing the right thing with my easy warm-up, low-rev routine and 5K changes with Liqui-Moly Synthetic 10W-60.

At last analysis for these bearings, Blackstone had reported: "This is the least amount of metal to come out of this engine so far. There's just 2 ppm aluminum, and iron is in great shape at 9 ppm. Your BMW is wearing well for the type, and shows no signs of poor bearing wear, or any other issues for that matter. Insolubles tested at just a trace level, so oil filtration is working well, and there's no contamination in the sample. You're taking great care of this M3!".

Future Blackstone reports will establish a new bearing material baseline for this S65, but that's two oil changes away because I plan the first change to occur at just 2K miles so we can cut open the filter to check for anything unusual.

Those look good! Glad you did the BE for preventative measures.

cognoscenti wrote

Hi all,

Glad to offer my first contribution to the thread. My car is a 2011.75, and swapping for BE Bearings and ARP bolts at 75K miles is just part of the regular maintenance schedule, as far as I'm concerned. I also had them swap in new OEM motor mounts as preventative maintenance while they were in there, and have definitely noticed less NVH afterwards. The stock ones were not leaking yet but were pretty much finished.

Thanks to Eurowise in Charlotte, for doing a great job!

I feel like the pic shows that I'm doing the right thing with my easy warm-up, low-rev routine and 5K changes with Liqui-Moly Synthetic 10W-60.

At last analysis for these bearings, Blackstone had reported: "This is the least amount of metal to come out of this engine so far. There's just 2 ppm aluminum, and iron is in great shape at 9 ppm. Your BMW is wearing well for the type, and shows no signs of poor bearing wear, or any other issues for that matter. Insolubles tested at just a trace level, so oil filtration is working well, and there's no contamination in the sample. You're taking great care of this M3!".

Future Blackstone reports will establish a new bearing material baseline for this S65, but that's two oil changes away because I plan the first change to occur at just 2K miles so we can cut open the filter to check for anything unusual.

Wow, great looking 75k shells!

Bearing Change Finally!

2010 E92 M3
85k miles - 6 track days
OEM bearings were 088/089

Put in BE Bearings and ARP bolts.

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Work done by Zolti at Auto Talent, a BMW/Porsche shop in Gardena, California.
BE bearings, BE/ARP connecting rod bolts.
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Busy week:

2008 M3 DCT @ 72,447mi


2011 M3 6MT@ 105,852mi


And some S54 action while we're at it:

2004 M3 6MT @ 99,082

2010 M3 removed at 105k