S65 Destruction

[SoCalRPM]

It does look like there's some major pitting in the original RB, although they do look as if the wear was fairly even otherwise.

Any way to know if there's a correlation between RB wear and mains failure?

[Nugget]

Similar happened to my car, except it was still running but with audible knocking when we tore it down.
This is what my original rod bearings looked like at 90,000kms.






They were replaced with VAC and ARP bolts.
6 months later number 1 main spun.











Standard maintenance schedule.
Car never saw a track while I had it (and it didn't appear the previous owner tracked it either) and only a couple of hard country road drives. Mostly standard daily driving. Which may have been worse with lots of stop start and short trips.

[SoCalRPM]

Sucks. Bummer that happened to you, too. This is the stuff nightmares are made of.

Any way to monitor Main wear through oil analysis or anything?

[Dr. Dre]

Originally Posted by sirploppy

Now THIS is the stuff that keeps me up at night. Like many have done, planning on doing rod bearing replacement soon - BE bearings, ARP bolts. Then to see this, knowing that in spite of my due diligence and preventative maintenance, I might still be kicked in the balls at any moment. I know, there have been very few mains I've seen on here go so far, and you can't live your life in fear. It's just that I want to keep this car till the end of time and I just hate having the main/rod bearings of Damocles swinging above me.

Don't worry about it. Many on this forum have said it only affects 2%.

[Jobe.]

Originally Posted by dparm

Would be curious to hear about the engine's history, e.g. maintenance, driving style, climate.

Never tracked.

Factory BMW oil used. Oil change interval every 3k miles.

[SYT_Shadow]

Originally Posted by SoCalRPM

Sucks. Bummer that happened to you, too. This is the stuff nightmares are made of.

Any way to monitor Main wear through oil analysis or anything?

No way to monitor it in the newer cars as the bearings are the alu/tin ones like the post-2010 rod bearings

[SoCalRPM]

Originally Posted by SYT_Shadow

No way to monitor it in the newer cars as the bearings are the alu/tin ones like the post-2010 rod bearings

Thought not. Oh, well.

Choose your destiny ---> Ignorance is bliss, or live in fear.

[SYT_Shadow]

Originally Posted by SoCalRPM

Thought not. Oh, well.

Choose your destiny ---> Ignorance is bliss, or live in fear.

Rod bearings are a small percentage of S65s. Around 2%

Main bearings are a much smaller percentage

Everyone has to do the risk analysis on their own. I feel it was enough to change rod bearings only on both my M3s.

[notouching]

I understand that nobody makes properly toleranced main bearings for S65/S85 because of the tooling investment it would take.

Would it be possible/cheaper to design and produce a crank that would be a tiny bit thinner at those areas to provide proper gap between it and the bearings?

[MSY]

Not worth it in my view given chances are so low

[Nugget]

Originally Posted by notouching

I understand that nobody makes properly toleranced main bearings for S65/S85 because of the tooling investment it would take.

Would it be possible/cheaper to design and produce a crank that would be a tiny bit thinner at those areas to provide proper gap between it and the bearings?

When I was going to rebuild mine the advice I got was to use WPC coated standard main bearings.

[GORDON.M3]

I don't know why but it seems like 2011 is a very problematic year. I see more engine failures in 2011 than I do with 2008 recently.

[Redd]

Originally Posted by SYT_Shadow

Main bearings are a much smaller percentage

I would disagree with this figure. While it may be true only 2% have experienced engine failure due to RB, those who preemptively replaced their RBs I think 70% saw excessive wear. We can assume that if those RBs hadn't been replaced when they were, they would have failed eventually.

Bear in mind that BMW doesn't prescribe an RB replacement schedule. So they are literally ticking time bombs. It's not if, but when.

[are0lies]

Originally Posted by GORDON.M3

I don't know why but it seems like 2011 is a very problematic year. I see more engine failures in 2011 than I do with 2008 recently.

Don't say that!

[bigjae1976]

I believe there was a theory and some evidence that a #1 main failure is the direct result being supercharged.

For those that are willfully nag to go the extra step...

I have an S54 crank that I've microblue treated with WPC treated main bearings. Someone REM polished an S54 crank as well. I've been told that you can REM polish and then MB treat the crank and then use MB treated bearings for the ultimate in oil retention and friction reduction.

I might try the REM and microblue formula on my next S54 rebuild.

[Green-Eggs]

Originally Posted by Nugget

When I was going to rebuild mine the advice I got was to use WPC coated standard main bearings.

If you're doing a rebuild, that means the crank is out of the engine. If the crank is out of the engine, it only costs about $200 to have the main journals resized to correct specifications and the crank re-heat treated. The cost of fixing correctly is a fraction of the total cost of rebuilding the S65. My advice would have been to fix it the right way. Hard for me to imagine the reasoning for WPC when the savings is $120 at most.

[Nugget]

Originally Posted by Green-Eggs

If you're doing a rebuild, that means the crank is out of the engine. If the crank is out of the engine, it only costs about $200 to have the main journals resized to correct specifications and the crank re-heat treated. The cost of fixing correctly is a fraction of the total cost of rebuilding the S65. My advice would have been to fix it the right way. Hard for me to imagine the reasoning for WPC when the savings is $120 at most.

I didn't say it was good advice.

[maicol76]

Originally Posted by Nugget

Similar happened to my car, except it was still running but with audible knocking when we tore it down.
This is what my original rod bearings looked like at 90,000kms.






They were replaced with VAC and ARP bolts.
6 months later number 1 main spun.











Standard maintenance schedule.
Car never saw a track while I had it (and it didn't appear the previous owner tracked it either) and only a couple of hard country road drives. Mostly standard daily driving. Which may have been worse with lots of stop start and short trips.

Mine was the same as you at 23900km. 1st main bearing failure. I posted it few years ago.

[SYT_Shadow]

Originally Posted by Redd

I would disagree with this figure. While it may be true only 2% have experienced engine failure due to RB, those who preemptively replaced their RBs I think 70% saw excessive wear. We can assume that if those RBs hadn't been replaced when they were, they would have failed eventually.

Bear in mind that BMW doesn't prescribe an RB replacement schedule. So they are literally ticking time bombs. It's not if, but when.

There are different things at play

One is the premature RB wear on the S65. This may only blow up 2% of engines, but almost 100% of the engines opened show premature wear. Both of mine sure did and all 7 cars I've done this to looked pretty bad.

Main bearings seem to last longer than the rod bearings and fail less.


Separately, no one should run the rod bearings of a M high revving engine past 100k. The E46M doesn't have specific rod bearing issues but it's still a good idea to replaced them around 100k miles.

[Mvy]

Originally Posted by SYT_Shadow

No way to monitor it in the newer cars as the bearings are the alu/tin ones like the post-2010 rod bearings

Not to stir up a shit storm on this topic but are you sure Shadow? How about just watching aluminum and tin in the oil report instead of lead and copper? Its certainly not as easy to spot since lead and copper only came from the bearings in the past but you should if you are sampling over time note higher than average aluminum and tin as the warning signs of bearing wear. OA is certainly not perfect, but if you do it every oil change over years its a tool to help see if conditions change inside the motor.

[SYT_Shadow]

Originally Posted by Mvy

Not to stir up a shit storm on this topic but are you sure Shadow? How about just watching aluminum and tin in the oil report instead of lead and copper? Its certainly not as easy to spot since lead and copper only came from the bearings in the past but you should if you are sampling over time note higher than average aluminum and tin as the warning signs of bearing wear. OA is certainly not perfect, but if you do it every oil change over years its a tool to help see if conditions change inside the motor.

the thing is there will always be alu in the reports

Oil Analysis is not super precise. If you do it for a long time you can see trends, but cars get a good report and do their bearings and they're terrible.

It may be possible to spot the trend

[SDPLV]

Originally Posted by GORDON.M3

I don't know why but it seems like 2011 is a very problematic year. I see more engine failures in 2011 than I do with 2008 recently.

Not good since I thought I read more 2008s were made than other years. Need to fact check me on that though.