Rod Bearings?

[horsepower_and_hounds]

Well it is probably a good idea for the obsessive at this point. We know that many E90/92 had common wear of them and most did it if they were going to supercharge. But so far 6 years into the F8x platform and many cars over the 60-70k miles I have yet to hear of an issue but I am curious to the numbers at 10 years. Could be the S55 had improved rod oiling...... We will see

[JamesGames]

Originally Posted by horsepower_and_hounds

Well it is probably a good idea for the obsessive at this point. We know that many E90/92 had common wear of them and most did it if they were going to supercharge. But so far 6 years into the F8x platform and many cars over the 60-70k miles I have yet to hear of an issue but I am curious to the numbers at 10 years. Could be the S55 had improved rod oiling...... We will see

Keyword "obsessive". I wouldn't recommend this be done just because. While the E9x had bearing failures, that motor was the S65 V8 and not similar at all to the F8X's S55. The S55 is extremely similar to the N55, and N55 seemed to do fine. Not saying that it's impossible to have abnormally high bearing wear, but if you must compare the past, the N55 should be the one used not the S65. Just my 2 cents

[BzsBimmer]

Agree. I haven’t seen any bearings as bad as my E90 M3

Those bearings have a bit of wear to them but probably within spec.

Oil sampling may not be telling about bearing wear since they removed the copper layer during the latter years of S65.

Statistically sure, engine damage can happen due to rod bearings but right now it’s looking like 0.0000001% lol

I’m sure this thread will bring out the doomsday theorists and rod bearing sales are going to go through the roof.

[jpy1980]

Interesting to see RK tunes 1100hp rod bearings looking pretty good:

Scroll to 7:09

[Bmwlmr99]

I have 93,000miles and running strong....no crank hub fix either ...stage 2 tune full exhaust, crushing Camaro's, zl1 and c7 zo6 from a roll... zl1 and zo6 where pretty close to stock....other cars bolt on cam e85 etc....I'm strictly on a 93 octane only tune

[Twistm4]

Looks like totally normal bearing wear to me you silly goons.

Only on an M platform do you find people willing to pay thousands to fix things that not only 1) would never likely become an issue. but 2) have not even have many DOCUMENTED issues to begin with.

Save yo money.

Open your oil filters up and you'll see where those tiny pieces of bearing are going, but it's not and hasn't been an issue.

[aquarius08]

2015 with ~60k miles, stock. Got a distinct knocking sound this morning. Suspected rod bearings as there seems to be some metal shavings in the oil. Waiting on definitive confirmation though.

I have been the only owner and maintained it like a gem. No tunes, track days, nothing. Driven mostly in LA traffic :/

[IamFODI]

Poking a head in here from the E9x side.

For those unfamiliar, the E9x M3 switched rod bearings ~halfway through its production run, and the new ones look very similar to the ones posted here. For years, it was reasonably assumed that the discoloration implied wear-through of the top layer, which should not happen unless something's seriously wrong.

Recently, someone finally took the obvious step of sanding down an LCI bearing to see the layers. In that experiment, the discoloration disappeared before the top layer was worn through, and the intermediate layer looks different from anything anyone could recall seeing in pics of used LCI bearings. This strongly suggests that much if not most of the discoloration observed on used LCI bearings is merely superficial, and that those bearings likely had a lot more life left in them than their ugliness suggested.

I post this here NOT to tell you that all is well with your rod bearings (or ours); just to advise caution before concluding from pics that all is lost.

FWIW.

[jpy1980]

Originally Posted by IamFODI

Poking a head in here from the E9x side.

For those unfamiliar, the E9x M3 switched rod bearings ~halfway through its production run, and the new ones look very similar to the ones posted here. For years, it was reasonably assumed that the discoloration implied wear-through of the top layer, which should not happen unless something's seriously wrong.

Recently, someone finally took the obvious step of sanding down an LCI bearing to see the layers. In that experiment, the discoloration disappeared before the top layer was worn through, and the intermediate layer looks different from anything anyone could recall seeing in pics of used LCI bearings. This strongly suggests that much if not most of the discoloration observed on used LCI bearings is merely superficial, and that those bearings likely had a lot more life left in them than their ugliness suggested.

I post this here NOT to tell you that all is well with your rod bearings (or ours); just to advise caution before concluding from pics that all is lost.

FWIW.

Interesting! Good to hear this especially coming from an e9x owner as I know the RB issue is a big deal to you guys. Do you think that they used the same bearings as the e9x LCI on the F8x motor?

[IamFODI]

Originally Posted by jpy1980

Interesting! Good to hear this especially coming from an e9x owner as I know the RB issue is a big deal to you guys. Do you think that they used the same bearings as the e9x LCI on the F8x motor?

Different part numbers. Can't say beyond that.

[BzsBimmer]

Different PN but I’d imagine same production process, if not better for F8X bearings which would be why we don’t really hear about actual failures other than people assuming based on looks, they’ve failed like E9X bearings.

Coming from an E90 M3, I had a lot of miles but no bearing failure or signs of them. Did oil analysis on every oil change and these were early MY bearings mind you... (Pre LCI).

[65fastback]

pffft...I can't believe I am seeing a rod bearing thread in the F8x section. just sayin.

[horsepower_and_hounds]

Originally Posted by 65fastback

pffft...I can't believe I am seeing a rod bearing thread in the F8x section. just sayin.

It is all over the FB members threads also....... and it really blew up there.

[FriedPiston]

Sorry to sound condescending, but some of you guys may be overthinking this a bit. OP's question is whether he should replace the rod bearings as part of a crank hub service, not whether the rod bearings are a known failure point on the S55. Only time will tell how the rod bearings will fare on this platform, but just know that the S55 shares the same rod bearings as the N55, and there have been a few N55s with RB failure.

IMO, anyone with over 45k miles on the engine, and has the means to afford the service, should replace them for peace of mind. More so if one plans on keeping the car for another 100k miles, or if they're not the original owner. However, I would advise against getting this service done if you have no long term plans in keeping the car.

Blackstone UOA shouldn't be used as an end all be all source of RB diagnosis. I've sent them a sample from a spun rod S55 caused by a heavily (meth) contaminated oil, and the analysis had zero mention of such condition; just increased calcium count. For comparison, I sent them a sample from an 18k-mile S55 with brand new seals, sensors, accessories, etc, and it's funny how their analysis showed higher aluminum and other metal count than the ones from the failed engine -- the 18k-mile engine passed both leak-down and compression tests with healthy scores.

As for Jordan's single turbo F80, his engine was built (unsure of specs) and the car is certainly not his daily. However, I wouldn't peg Jordan as the type of tuner who would keep the original rod bearings during an engine tear down.

[sly1types]

Looks like I might be needing some rod bearings. I just started tracking this car last year, so maybe 12 days. It's a 2016 that I bought in 2018 with like 28k miles. It has been tuned since 35k miles.

So frustrating, I didn't think this car would have the rod bearing issues like my E46M3. Also I have been doing oil samples on the X5m.

What's the go to bearing replacement on these S55s?

[Groganrocket]

Originally Posted by sly1types

Looks like I might be needing some rod bearings. I just started tracking this car last year, so maybe 12 days. It's a 2016 that I bought in 2018 with like 28k miles. It has been tuned since 35k miles.

So frustrating, I didn't think this car would have the rod bearing issues like my E46M3. Also I have been doing oil samples on the X5m.

What's the go to bearing replacement on these S55s?

That’s normal from what I’ve seen and I don’t believe it’s bearing material
,my m3 does the same and it has 6k and never been tracked or tuned. There is another thread about this also.

[sly1types]

Originally Posted by Groganrocket

That’s normal from what I’ve seen and I don’t believe it’s bearing material
,my m3 does the same and it has 6k and never been tracked or tuned. There is another thread about this also.

Do you have a link for the other thread? I have changed this oil more than 10x and never seen this...

I would argue this looks like copper from bearings.

[Groganrocket]

Originally Posted by sly1types

Do you have a link for the other thread? I have changed this oil more than 10x and never seen this...

I would argue this looks like copper from bearings.

https://f80.bimmerpost.com/forums/sh...117&page=2

[Info@mad-us.com]

Agh man not again from a former e9x and f80 owner.

[SYT_Shadow]

Originally Posted by FriedPiston

Blackstone UOA shouldn't be used as an end all be all source of RB diagnosis. I've sent them a sample from a spun rod S55 caused by a heavily (meth) contaminated oil, and the analysis had zero mention of such condition; just increased calcium count. For comparison, I sent them a sample from an 18k-mile S55 with brand new seals, sensors, accessories, etc, and it's funny how their analysis showed higher aluminum and other metal count than the ones from the failed engine -- the 18k-mile engine passed both leak-down and compression tests with healthy scores.
.

Exactly, well said. Over time I've seen more than one person with a good blackstone reading blow their engine shortly after due to rod bearings

I don't bother anymore.

[TopJimmy]

Originally Posted by sly1types

Do you have a link for the other thread? I have changed this oil more than 10x and never seen this...

I would argue this looks like copper from bearings.

Sly,
That's a little ugly there Bro… I'm hoping the best for you.
-TJ

[sly1types]

Originally Posted by TopJimmy

Sly,
That's a little ugly there Bro… I'm hoping the best for you.
-TJ

Thanks, I just ordered all the colors of the OE rod bearings hoping that its just some worn bearings. Plan is to pull it apart in the new couple weeks. I couldn't find all the colors of WPC coated ones in stock.

Talking to some people it could be a bent rod, but unlikely with stock turbos and good tunes, my tunes torque don't come on too early and i never hit it below 3k rpms...

In the event of a bent rod i'm going to do some Forged CP pistons and Forged Corrillo rods from Lang Racing then put in some supertech springs and have the head gone through and ported/polished.

How did your built engine turn out? Any pointers or things you wish you would or wouldn't have done?