Rod Bearing Showcase Thread

[m3nt0s]

Saw these posted on Reddit. 170k mile rod bearings.

https://www.reddit.com/r/E46M3/comments/oj40mm/170000_miles_on_original_rod_bearings/

I had nightmares that looked like this the night before my rod bearings were done!

[Samsonite79]

2003 M3 production date 10/02' w/ 110k (had the bearing recall done prior by previous owner at some point mileage unknown best guess was about 50-60k). I've been doing only track only miles, only a track queen.

[cobra]

What do we define as "bad"? I see varying levels of wear but nothing outright alarming, except for that Reddit post which has me think it was assembled wrong or starved of oil or something.

Do we have enough data to say "you should replace your bearings at X miles regardless of oil analysis" yet?

[Icecream]

These came out of my first S54 that spun a bearing. 180kish on them, always proper warm up and then redline every chance I get. Spun one not shown. Kinda messed up that all these could look so good and one still decided to spin. If I really want to stretch my imagination the new bmw turbo oil was in it at the time, with how good these bearings look, maybe that shell stuff wasn’t up to the task. Ran castrol up until the last couple of oil changes. Like I said a stretch and we will never know, but I probably won’t be using the shell stuff again. Ran it on the new motor that blew up too but that was a unique circumstance.



.

[Thoglan]

Wow, hard to believe one didn't let go. Owner is very lucky.

Although it is lucky one didn't spin, I would still be seriously concerned about the condition of the crank with the shells looking like that. Not necessarily away laughing.

[sapote]

Saw these posted on Reddit. 170k mile rod bearings

He squeezed out every mile of the bearings -- what's a timing. Once the copper layer is worn through then the crank will hit the steel layer and be damged.
The bearings/crank journals matched perfectly for this engine: look at how the red copper worn down uniformly around 360* instead of just a short arc at the middle of the bearing shell curve. This means the bearings have a very small clearance -- minimum side on the spec.

[Andrew 06M3Cab]

Wow, hard to believe one didn't let go. Owner is very lucky.

[stephen]

Saw these posted on Reddit. 170k mile rod bearings.

https://www.reddit.com/r/E46M3/comments/oj40mm/170000_miles_on_original_rod_bearings/

[sapote]

Had Rod Bearing Recall done at 15,509 and these done at 208,426. So 193,000 on these…

Too dark to tell if copper shown or not, but they seem to be in good shape for 193K miles.
Why changed now and not when it's around 100K?

[old///MFanatic]

Had Rod Bearing Recall done at 15,509 and these done at 208,426. So 193,000 on these…

[sapote]

Had the rod bearing recall done around 25k and then these done at 145k. Mostly highway miles, but still, they were ready to change out. Glad i did it now and didnt wait any longer. Blackstone wasnt showing much copper

Low resolution pic -- I couldn't see much of detail.

[sapote]

Don’t know when the previous owner changed them. But glad I got it done.

Not too bad at all.

[sapote]

Funny, my oil analysis consistently looked fine. Blackstone's report stated "Your original rod bearings still look good with lead (the primary bearing element) at a perfectly average 6 ppm". I'm glad I replaced them anyway.

I agree that the oil analysis is matching with the bearings condition. At 133K miles they looks fine with #3 just showing copper. You could easily get another 5K but it's good time to change.

[cobra]

Interesting to see the lack of correlation between mileage and wear...

Also the lack of correlation between blackstone oil reports and wear...

[Andrew 06M3Cab]

216,500 km (133,000 miles). Top of number #3 was worst - copper just starting to show through. Funny, my oil analysis consistently looked fine. Blackstone's report stated "Your original rod bearings still look good with lead (the primary bearing element) at a perfectly average 6 ppm". I'm glad I replaced them anyway.