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Comprehensive S85 Rod Bearing Picture Thread

551K views 1K replies 279 participants last post by  CQ_CQ 
#1 · (Edited)
With all the discussion of late on the subject of rod bearings, I thought it would be a good idea to have a single thread to collect pictures of rod bearings which have been preventively changed. I say preventative because if there has been an engine failure, there are several possible reasons that can't be isolated as easily as in a currently running engine.

Edit: An excellent discussion on M3Post about the S65/S85 Rod Bearings and their measurements. Well worth the read as the most well documented and concise discussion about the hypothesized source of the problem and potential solutions.

As people add their pictures below, please include:
- mileage
- owner history
- average oil change interval
- oil analysis reports if available
- reason you decided to change (fear, suspect noise, suspect oil analysis, hard usage, etc)
- DIY or shop changed
- link to your change thread I you have one

Hopefully over time we will drag up some preventative changes that don't show significant wear, but as of starting this thread, I have yet to see a set of bearings that look "great".




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#458 ·
Finally got time to clean and capture my RB that were replaced a month ago by Turner. 2008 6spd with 97k miles. Even wear within a bank but I am surprised that 6-10 are much more worn than 1-5. Only light or no signs of copper showing on 1-5 uppers but all the 6-10 uppers show a lot of copper.
 

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#464 ·
I never use D (auto). Only use paddles/stick in S4 up to S6. It is annoying (to me) in auto mode
 
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#465 ·
I always push the M button after starting. I only push the gearshift into D mode in the morning while drinking coffee. The car will shift much faster in D mode if you make sure you have five bars for shifting (the button behind the gearshift controls that). You probably have it at one bar right now
 
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#467 ·
The gas savings is not that much running in M mode. It is the pushing of the foot that uses more gas. I prefer to always have over 500 HP at the ready
 
#471 ·
Speaking of mishaps...

Once I dropped off my car at BMW of Fremont for a simple oil change. I took a photo of the mileage before dropping it off. When I picked it back up in the evening and was driving back, I noticed they put around 17 miles on the car! 17 freaking miles!!!! How the heck did they manage to do that? I tried speaking with the service adviser and he straight up denied it.
 
#472 · (Edited)
Wear on bearing at longer standstill

I’m curious, how much wear is it possible to bearing (using TWS), if the car is used maybe once a week, or even less?
Nevertheless, that the car is then driven very easy, with low rpm, till it gets to the appropriate engine-oil temperature.
In meaning, if, or does it, oil film in that period of time, when the car is not used, drains completely from the bearing and area around it.
 
#473 · (Edited)
2008 E63 with 102K miles on it. replaced with stocker BMW Red and Blue. No strange issues with the stock BMW bearings as witnessed by some other members. I did not do the work, had no time. I used the only local indy shop I trust. Steve, at Superior Automotive in Morgan Hill, Ca.

He did not get a picture of the crank with no break-in grease smeared on it, unfortunately, but he did say it was mirror polished and smooth. The sides of the rods, where they were next to each other, showed no signs of galling or bluing.

He plasigauged every single NEW bearing, torquing with the old rod bolts, to get a measurement, then tossing the old rod bolts out to do the final install of the new rod bolts. All were around .0017 -.0018, which I thought was good.

the entire set, not sure which are top and bottom, but, as you can see, it matters little.


the first two he pulled, the worn ones are tops


A rod with original machine marks on the inner edge where it faces another rod. No clearance problems here. (journal has grease on it)


plastigauge shot of a new bearing, showing just shy of .002"
 
#475 ·
I do, pretty much: The first 30K miles it was thrashed, The guy had to replace the clutch and diff!! The next owner was an investment manager who owned lots of nice toys, he was a staid gentleman who drove it on a long commute most days. Drove it the next 65K miles. He took decent care of it, and it had an unremarkable service record. Recently did the rear throttle actuator, I ended up doing the other with Odometer gears. The only strange sign was-- he was using Mobile 10W40 for the last couple of years. Not even sure if that oil is Ester-based? Now it's going to run on Redline. I plan to always warm it up and change oil on a regular schedule. With the clearances I have, being on the looser-end of new, I am not worried about the cold-start properties.
 
#476 ·
The only Mobil1 10W40 I know of is the "high mileage" formula. Is that what it was getting?

Regardless, 100K out of a set of bearings from an engine that spent the first third of its life being run hard is pretty impressive. My '08 M5 only has 37K miles on it, but I vacillate between feeling like it'll easily be safe for another 30-40K miles, and worrying that I'll need to preemptively change the bearings at 50K.
 
#477 · (Edited)
I wonder if a lot of the reason for the bearing failures is just due to the high-RPM nature of the S85. Obviously 8000rpm is tougher on all of the engine parts, compared to 6000rpm. In my cars with torquey V8s, I can still get good thrust without spinning the motor to redline--in the M5, the engine just sounds and feels so good when it gets into the powerband that I want to keep my foot in it instead of grabbing the next gear.

I always let the oil get up to temp before revving to more than 3000rpm, but once the motor is warm, it gets quite a few trips to redline. I've got several good UOAs from the previous owner. I'm curious to see how my next one will look, but given the number of miles I drive each year, it'll probably be a couple years before the car has accumulated 5000 miles.
 
#479 ·
I have seen prices vary between $2200-$3000 depending on where you live.
 
#480 · (Edited)
My Blackstone report: Bottom line, they feel there were no red flags that indicated a serious issue, at 102K miles. 5700 miles on the oil that was tested.

 
#482 ·
look back a few posts for the replacement pictures. They don't look super great to me, but compared to some of the disasters I have seen, not that bad, for 102K miles. Unfortunately, it took me a long time to finally send in the oil sample. I did the rod bearings before I knew what the report was.

The part to "get" is: I was installing a supercharger on a 102K motor. Regardless of what the oil report said, I would have replaced the bearings anyway. I only posted the report for this thread so people can see what another set of 102K rod bearings look like, and then, how the report read at that mileage.
 
#483 ·
Mike, your bearings look pretty good for 102k. Very minimal copper showing.
 
#484 ·
Quick question. I have an appointment to replace my rod bearing in two weeks. They plan to use BMW OEM bearings. Should I go with those or are there after market I should have them use
 
#486 ·
Any chance of them being available in the next 10 days
 
#488 ·
They would need to be in LA on Monday morning of the 23rd. It doesn't look like they will make it by then. I am sure I will be fine with the OEM. They are a new design and I only need maybe 50K miles out of them and I will sell the car off.
 
#489 ·
IMHO, I think OE is fine. I mean, look at mine after 100K miles. All bearings you can buy are based off of OEM bearings that have been treated one way or another. I would not consider a bearing with a film on it, since it will reduce the clearance and make things even tighter. I thought about the WPC bearings, but--if you never want your crank to actually touch the bearing surface, then why have a harder surface? You need that soft first layer for embed-ability for junk in your oil. Again, see my pictures of stocker at 100K miles.

I have done builds on other motors with pure Aluminum bearings (real hard) that still wiped out after a short time, due to other issues, so, if you are going to wipe your bearings in a short time, you probably have other issues that are not "just" your bearing choice.

That said, with my VT2-650 I have a 8400 RPM redline now, so, we shall see how they hold up.
 
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#490 ·
I would be perfectly content owning this engine, using OEM bearings and changing them every 75k or so...if the OEM bearings hadn't changed and gotten harder by removing lead from the Babbitt layer.

The WPC treatment does harden the surface very slightly, but an insignificant amount. In comparison to the hardness added in the "new" 702/703 bearings.

Every motor I build from now on will use the BE Bearings, even if for that reason alone. The S65 / S85 cranks are relatively soft as is, ill take the softest bearing I can. By most accounts, the 702/703 bearings are showing up in S65 failures with more significant crank journal damage than the older 088/089 bearings did.
 
#491 ·
are these BE bearings made from scratch?
 
#492 ·
Effectively, yes. They are manufactured by Clevite with many of the OEM specs taken into account, but adding a bit of additional oil clearance to establish what has long been considered an optimal journal diameter to clearance ratio.

Also, since there was no need/desire to meet ROHS specifications, it's a true "tri-metal" bearing.

I have two cranks at a shop right now being welded and ground and had intended to grind the rod journals on both about half a thou under to increase clearance. After these became available a couple of weeks ago I called the machinist and asked what they recommended (they see a ton of these and S65 cranks) and their thought was that the higher clearance bearing would be provide more consistency as opposed to grinding (more likely polishing to avoid risk of tapering a journal). I am having them harden the cranks anyway though.

The BE Bearings are designed for use with 10W-60 as well, so the purists can sleep better. ;)
 
#493 ·
I will have the shop take a picture of them when he takes them out. I have 112K miles on the car and ordered it new. It was the first one at my dealership in Dec. 2005.
 
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#499 ·
so, what you guys are saying is, I just installed a time-bomb in my car?

how did I miss the "modern bearing destroying my S85" thread, and the BE Bearing thread?
 
#495 · (Edited)
I just ordered BE bearings from Bimmerzone and redo bearing swap with these new clevite this weekend. See my post #443 back to few months ago swapped with 702/703 with WPC. Will post some pictures 4100 mls on WPC bearing but should not much to see with this mileage. I not feel comfortable and not sleep well once I knew that this 702/703 have 3.8 times harden then previous 088/089 and have negative impact to crankshaft journal and some proof pictures posted by Jcolley with only 14K on it looked like 50K miles because of clearance. Thinner oil doesn't help at all. Since I still remember all the steps swapping out the bearing and hope will take less hours for the second time and ready for my back pain again. At the same time I also change out all the fuel injectors with new. I got a best deal $34 each and free shipping with FedEx next AM delivery.:laugh
 
#497 ·
Don't expect the 702/703 bearings to look anything like the 088/089 bearings when removed. Most people look at the 702/703's and think they see little wear because they don't see the obvious beating into the lead and/or copper. But since 702/703's don't have lead or copper, it's an invalid comparison. Just a head's up on that.

I'm one of the guys behind the BE Bearing design. So if you have any questions, feel free to ask.
 
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