Official S65 Rod Bearing Condition Example Thread

[Raek]

Did mine for peace of mind. They look fine to me.

2008 - 19,990 miles - not heavily driven.

[Helmsman]

Cheers Raek. Exactly the way I expect mine to look like with current 35k on them. Can't see them in there, but still convinced.
PS. Any close ups on those fine bearings mate?

[doogee]

Originally Posted by Raek

Did mine for peace of mind. They look fine to me.

2008 - 19,990 miles - not heavily driven.

These do not look fine at all. Heavy wear for 20k.

[Raek]

Originally Posted by doogee

These do not look fine at all. Heavy wear for 20k.

You think? The only ones I was concerned with were #6 and #3 (which don't look THAT bad), but the others don't really seem too worn at all.

*I put the same picture up twice in the original post by mistake.

[deansbimmer]

Originally Posted by Raek

You think? The only one I was concerned with was #6, but the others don't really seem too worn at all.

He's right. None of that wear is acceptable based on what the industry considers normal. There should be next to zero visible contact wear at that mileage. It helps to confirm that all S65's have a problem. As far as S65's go yours aren't too bad at all considering every original bearing ever pulled from an S65 has some sort of accelerated wear pattern.

[kyrix1st]

Will do mine as soon as winter is over.

It would be interesting to see as it has been on 5w-40 for 55k km after 40k km of dealer serviced 10w60. Expecting to see some copper layer on at least one of the cylinders.

[Scharbag]

Originally Posted by deansbimmer

He's right. None of that wear is acceptable based on what the industry considers normal. There should be next to zero visible contact wear at that mileage. It helps to confirm that all S65's have a problem. As far as S65's go yours aren't too bad at all considering every original bearing ever pulled from an S65 has some sort of accelerated wear pattern.

+1

Bearing wear is not normal. Go take a look at 100k mile bearings out of a Honda S2000 or Integra type R. They will not look anything like S65 bearings even though they are ~0.5L per piston, produce ~100HP/L and spin to 8,000+.

Bottom line, BMW screwed up. But I can live with it cause it is such a nice engine to drive.

[///M Power-Belgium]

Originally Posted by Helmsman

Cheers Raek. Exactly the way I expect mine to look like with current 35k on them. Can't see them in there, but still convinced.
PS. Any close ups on those fine bearings mate?

Fine bearings ? Keep in mind they ran only 20K miles ,and they show already premature wear ...
This bearings at 50K would look like 5H1T !

Note: One of them is already through the first lead layer ...

[Raek]

Originally Posted by ///M Power-Belgium

Fine bearings ? Keep in mind they ran only 20K miles ,and they show already premature wear ...
This bearings at 50K would look like 5H1T !

Note: One of them is already through the first lead layer ...

I've gathered that from the responses by now, buddy. But, thanks for your enthusiasm!

The ones with the layer worn through are different sets..which is the most concerning.

[CHE///MIST3]

Given that we see so many pulled bearings worn to the copper (or beginning to), can you say that if run gently, the crank can ride on the copper portion for a very long time until it finally, either reaches the steel backing (unlikely), or, is run in a condition not optimal for the copper surface, such as high rpms on a cold motor ? I ask this because if reaching the copper were "the end" MANY MANY more 07-10 models would have seized by now.

Just trying to understand this bearing situation a little better !

GM

[pbonsalb]

Or be about to fail. A lot of these cars aren’t driven. People buy them but then park them and drive commuter cars or trucks instead. We see 10 year old cars with 20k miles on them.

[CHE///MIST3]

Originally Posted by pbonsalb

Or be about to fail. A lot of these cars aren’t driven. People buy them but then park them and drive commuter cars or trucks instead. We see 10 year old cars with 20k miles on them.

Yeah, true.... such as those very unfortunate buyers who purchase the car and it fails immediately after.

GM

[pbonsalb]

That is the worst case. My guess is that maybe 1% of cars have failed but it would suck to be among them. I had 3+ years of warranty when I bought mine as a CPO and changed the bearings when the warranty expired, but today nearly all the cars are out of warranty.

[dv13]

I saw some discussion on this in one of the threads but wasn't sure if anyone had investigated it further. Someone (maybe Malek?) had the thought that the original factory bolts might be the issue. It's an interesting thought. If the bolts were fine at assembly, but slowly lost their crush strength over time (stretching/material expansion? slowly backing out due to vibration??), would this result in a loss of proper shape and ultimately contact with the bearings which leads to failure?

This seems consistent with the data....engines are OK when new (<10k miles), but over time there is increased bearing wear and failure at some point for the worst cases, with variance in failure miles/time probably depending on assembly tolerance differences and engine operating/environmental conditions. It also seems that after bearing replacements and especially with the BE ARP bolts and ensuring a torque to spec that Malek/others have found no wear on the replacement VAC/Clevite bearings after a significant number of miles. Anecdotally, it would be easy to draw the conclusion that the small clearance is not really the issue, more the delta in clearance over time as that clearance degrades due to some other factor.

I'm now hearing a very faint knock on my car at 41k miles that I never heard previously. As listened to with a stethoscope on the oil pan, it sounds like a regular, rhythmic middle frequency knock/tap with engine speed. My thought is that I'm hearing my first signs of bearing contact, which if the bolt theory is correct would start slowly and increase over time until the bearing shape is distorted enough for flush enough contact to spin the bearing.

I'm not an expert on these matters (and pardon my ignorance!), but is there any way to measure this bolt crush/related bearing shape distortion in a meaningful way before the old bearings are removed? I strongly feel that this is a BMW materials/assembly issue that would impact every vehicle to some degree (even the 100k mile vehicles that are OK, for now) and also think that if it's something as "simple," but measurably able to correlate with bolts being defective (for whatever reasons), that it may be more likely to get a remedy from BMW than making the assumption that x% of engines were simply built incorrectly, which is much harder to prove given the various environmental conditions that each of these cars have been through over the past 10 years.

Can anyone with more knowledge on the subject comment? Thank you!

[jcolley]

I removed WPC treated OEM bearings at 14k miles that showed significant wear already, almost like some here at 50k. That was with OEM bolts.

I've removed BE Bearings at 5k on OEM bolts that had no similar wear pattern at all.

If the bolts were yielding due to cyclic stresses, it stands to reason that at least one case of bolt failure would have occurred.

[pbonsalb]

As for the bolts theory, engines have failed as early as 6k miles. It is possible but unlikely some machine or worker was out of spec because the problem spans 2008-2013 and arguably the S85 that began in 2005. These same style bolts have been used for many years without issue. And many replacement bearings have been installed with them without issue. And many replacement bearings have been installed with ARPs that some claim cause potential eccentricity issues. I personally do not think the problem is bolts. I am more inclined to go with the insufficient clearance theory — bearing to crank clearance that is insufficient regardless of bolt used.

[Richbot]

The only compelling argument I saw for the arp’s is removing a couple dozen chances for human error during reassembly. If they’re stronger or help the wear pattern, gravy, but that’s why I bought them so either I or my installer would have fewer chances to have an oopsie

[pbonsalb]

But there are supposedly good ARPs and bad ARPs and many bearing swaps have been done with the bad ARPs and no problems.

My guess is that maybe 1% and probably less of these cars have suffered failures. I’d further guess that maybe 3-4% have had preventative maintenance rid bearing changes. So 95% are untouched and doing fine.

While that makes it seem like the odds are with owners who do nothing, what worries me is that about 95% if removed bearings that have been posted have significantly more wear than would be expected. These cars are now all 5-10 years old, so you would think failure rates would be increasing. However, many cars seem to be not driven very much, and that could partially explain the still low percentage of failures.

[oldmanstyle]

Originally Posted by dv13

I saw some discussion on this in one of the threads but wasn't sure if anyone had investigated it further. Someone (maybe Malek?) had the thought that the original factory bolts might be the issue. It's an interesting thought. If the bolts were fine at assembly, but slowly lost their crush strength over time (stretching/material expansion? slowly backing out due to vibration??), would this result in a loss of proper shape and ultimately contact with the bearings which leads to failure?

This seems consistent with the data....engines are OK when new (<10k miles), but over time there is increased bearing wear and failure at some point for the worst cases

The stock rod bearing clearance has been measured to be too tight in multiple instances. The observed tight measurements match the observed bearing wear patterns in the failed engines. There's nothing to suggest that anything else is as responsible for the engine failures as that overly tight (in some cars) clearance setting.

[dv13]

OK--thanks guys. I didn't realize that the problem had been conclusively determined to be the lower clearance (whether the BMW spec is too small or assembly error) and not some other factor that was taking the clearance under spec.

[derbo]

Performance Technic did mine yesterday at 52k.



It does look worn out but is this considered highly worn? My car is a 2011 built in 05-2010.

[Scharbag]

Originally Posted by derbo

Performance Technic did mine yesterday at 52k.



It does look worn out but is this considered highly worn? My car is a 2011 built in 05-2010.

Sadly, for an S65, those look typical. For rod bearings in general, they are goodandfooked.

Good thing you did them!!!