[egebhardt]

I'm sure he's right. I'm just surprised a Mod with vast knowledge would give a short answer. I was expecting:
My Imola 46M had xx,000 miles on it when i changed them and they appeared x% worn. The 2nd time I changed them at 1xx,000 miles and they looked x% worn. The rod-bearing issues on the 46Ms and 9xMs are probably similar enough to compare but Obioban doesn't currently own a 9xM or at least it's not in his avatar.
Details help. That's all I'm saying. I'd like to buy a 9xM later this year or next so I'm following this section lately if you haven't noticed.

[Obioban]

Originally Posted by egebhardt

I'm sure he's right. I'm just surprised a Mod with vast knowledge would give a short answer. I was expecting:
My Imola 46M had xx,000 miles on it when i changed them and they appeared x% worn. The 2nd time I changed them at 1xx,000 miles and they looked x% worn. The rod-bearing issues on the 46Ms and 9xMs are probably similar enough to compare but Obioban doesn't currently own a 9xM or at least it's not in his avatar.
Details help. That's all I'm saying. I'd like to buy a 9xM later this year or next so I'm following this section lately if you haven't noticed.

My response assumed a passing knowledge of the S65's failure modes...

The S54 is not particularly relevant to the S65. The S65 has two rod bearing failure modes
1) lottery
2) wear

(2) seems to be roughly similar to the S54's wear. That said on the S54, you can track it with oil analysis and do it when oil analysis says it's time. This is possible on earlier S65s, but on later S65s they changed to a different bearing material that's much hard to glean meaningful date from. This failure mode likely tracks with time spent at high RPM.

(1) is the lottery based failure, that can strike at any mileage/age/drive cycle, likely due to the tolerance stack when the engine was assembled. The only (likely) fix is increased clearance (aftermarket) bearings, that bring the S65 to engine design norms. It applies to the crank bearings, as well as the rod bearings, though less frequently. The decreased frequency combined with replacing them being an engine out service means most people don't preventatively go after the crank bearings. I suspect it's too early to state that the aftermarket bearings are a guaranteed fix for the lottery failure mode, but so far I haven't seen any counter examples.

For the reasons above, the S54's bearing wear isn't particularly relevant. But, if you care, I replaced mine after 125,000 miles, ~10,000 of which were track miles.

I follow this because since I have another S54 in my life (e46 M3 wagon DD), I've been considering putting an s65, s85, or s62 into my e46 M3 coupe.

[egebhardt]

Thanks! My Inlaw's are in Jonestown and SIL are Shippensburg so I have an idea about your weather conditions.
I also found this earlier thread from your wagon.
http://www.m3forum.net/m3forum/showp...&postcount=344

[Obioban]

Originally Posted by egebhardt

Thanks! I also found this earlier thread from your wagon.
http://www.m3forum.net/m3forum/showp...&postcount=344

Ha, yep-- I didn't put WPC treated bearings in it a second time :P

200,000 miles and counting on that S54

[jeffgo888]

Originally Posted by Obioban

No driving style, however pointlessly conservative, is going help with the S65's rod bearing lottery.

Maybe true, maybe not true.
Im thinking its directly proportional to how much "stress" and "revs" your car goes through. The more "earlier" the parts gets lubricated, then Im thinking less stress and wear on the components. Hence, my idea of letting it warm up.
Maybe its wrong and fallacy on my part, and maybe not, but it doesnt hurt , my thinking.

I havent owned my E92 M3 for the longest time so cannot be authoritative, but you are right. The V8 , as amazing and performant as it is, makes weird sounds and has its own idiosyncracies, so to speak..
that said, the day I got the car, I drove it 1/2 mile to the shop and never drove it again until the bearings were replaced..

[jeffgo888]

Originally Posted by Obioban

Ha, yep-- I didn't put WPC treated bearings in it a second time :P

200,000 miles and counting on that S54

BE bearings on mine..

[albino09]

I'd love to read more about this "tolerance stack up" that's been mentioned. Is there a larger thread about all that?

[Obioban]

Originally Posted by albino09

I'd love to read more about this "tolerance stack up" that's been mentioned. Is there a larger thread about all that?

That's the s65-- not us.

[pbonsalb]

Originally Posted by albino09

I'd love to read more about this "tolerance stack up" that's been mentioned. Is there a larger thread about all that?

Yes, at E90post dot com there is a thread on clearance and tolerance stack concerning S65 rod bearings:

https://www.m3post.com/forums/showthread.php?t=892838

[albino09]

Originally Posted by Obioban

That's the s65-- not us.

I understand. I was casually looking at s65 sedans and wanted to get to know the rod bearing issue more intimately.

Originally Posted by pbonsalb

Yes, at E90post dot com there is a thread on clearance and tolerance stack concerning S65 rod bearings:

https://www.m3post.com/forums/showthread.php?t=892838

Thanks!

Edit: That link is by far some of the best forum investigative work I have ever read. So much information to absorb, it is not for the faint of heart.