Another Cracked S65 - Main Bearing Failure

Hi all,

I believe I've experienced the dreaded #1 main bearing failure. 2010 E90 with lead/copper bearings, and BEv2 bearings/BE-ARP 2000 bolts replaced at 130k (original post). The car has 141k miles.

The car has been making some "ticking" sounds at really low load for many months, probably at least 1000 miles. The startups have sounded pretty rattly for ~8 months now, but the sound always went away within 1 second and it's done a few track days since without a noticeable change until the last month or so ().

Fast forward to my last oil change, the filter was pretty loaded with copper and silvery metal (). Parked up the car ever since and found the time this weekend to tear it down. So far we stripped down the block and pulled the rod caps, and here's what we found...













#1 rod bearing spun, but no noticeable heat on the rod or crank. The journal also looks pretty good, I think that with a polish it would be very usable. The rest of the bearings were generally okay with wear from the metal being pumped around everywhere.

JonOhh and I will pull the bedplate and pan tomorrow. If the journal doesn't look cracked, we'll get some dye penetrant and check the crank/block. Wish us luck!

Hope the damage is not too extensive. Such a bummer…good luck with everything! Please keep us posted.

Ran into an annoying stand issue that took up almost half of the 2 hours that we spent today pulling the bedplate, so we didn't fully pull it out and will do so in the morning. However, the bearing and journal got HOT. Curiously the parting line of the shell seems to be perfect... so not sure what we'll find yet. Block doesn't have obvious heat damage from what I can see.

Let us know once you get the bedplate off. I'd be curious to see what the main looks like. The steel inlay is pretty tough, but on the block the aluminum--not so much.

If the main spun, the concern would be if the oil feed hole got cracked. If not, then it MIGHT BE a good candidate for decking the mains. Hopefully the crank isn't too bad. These cranks are nitrided, therefore, they seem to be rather hard and resilient if caught soon enough.

That looks like a lot of heat! Pull the bedplate and hope for the best.

Well, it was just as we expected. Here's what the bedplate side of the crank looked like at main #1. Yes, that's the crank, not the bearing.






Here was the actual bearing. Notice that it didn't actually spin but it got so hot that material transferred statically between the block and the back of the bearing.





And now, the sinister part...





The block is cracked in the usual spot, all the way up the oil passage and almost to the cylinder bores. The terrifying part to me is that this engine really barely made any noise, as you can see in the video linked in the OP. It was really hard to get it to make noise, and when it did, it was so quiet that you had to be in a garage surrounded by walls to hear it.

It didn't crank any slower than usual, and even up until it drove up into the garage that it sits in today, it ran beautifully.

Welp, I guess it's time to buy and rebuild another S65. I don't think I'll ever be able to trust an unknown-condition S65 again. What a shame, because the rest of the engine (bores included) are in beautiful shape.

Blast! It's def cracked! Well shoot. I wouldn't dismiss all the other parts just quite yet. At this point, you would need a new block&bedplate, a new conrod, and all associated bearings.

Have you tried taking out the crank and seeing if you could polish some of that copper off? I had the same scenario you had, sans the cracked block portion on my main #1 and piston #5.

You can try getting a good used block. $2500 for something on ebay.


Ebay listing

Maybe it's just me and/or the lighting, but all the BE conrod bearings look to show or are starting to show some copper coming through.

Can you take another picture of the BE bearings you pulled out with all the oil wiped off clean? This is very interesting.

That sucks. Sorry for your loss. At least you will know how to rebuild your next engine!

Sorry to hear man!
btw. Isnt ticking noise just a normal s65 sound? Or you mean intermittent ticking?
Here is the video same intermittent ticking as yoursAnd the issue was - heat shields expanding and hitting the headers.

T!m3 wrote

Sorry to hear man!
btw. Isnt ticking noise just a normal s65 sound? Or you mean intermittent ticking?
Here is the video same intermittent ticking as yours

And the issue was - heat shields expanding and hitting the headers.

Very interesting - that could very well be the noise. Makes it ever scarier...

lol, yeah…that doesn’t sound like heat shields.

charliev68 wrote

lol, yeah…that doesn’t sound like heat shields.

Thats what he said in the comments
Maybe the drivers side hs is loose,
coud be also a bad engine mounts

The good news is your motor wasn't seized so crank and block could be saved. Once motor is seized, block has micro cracks. If crank is destroyed, just go with VAC 4.4 kit or ask Carbahn for used cranks.

Were you supercharged? What oil model and weight have you been running before and now? For my own personal data logs of S65 engine failure and oil brand.

My chassis has gone through 2 motors on track. One the rod put a hole through the block, the other mains seized up. Once mains give, it will fill oil passages with glitter blocking oil flow to RBs. So we may never know how many motors reported failure due to RBs were caused by Mains.

Signature Wheel BMW wrote

The good news is your motor wasn't seized so crank and block could be saved. Once motor is seized, block has micro cracks. If crank is destroyed, just go with VAC 4.4 kit or ask Carbahn for used cranks.

Were you supercharged? What oil model and weight have you been running before and now? For my own personal data logs of S65 engine failure and oil brand.

My chassis has gone through 2 motors on track. One the rod put a hole through the block, the other mains seized up. Once mains give, it will fill oil passages with glitter blocking oil flow to RBs. So we may never know how many motors reported failure due to RBs were caused by Mains.

In my case the block is cracked even though the engine turned over very freely and the mains hadn't spun, pictures in one of the previous posts. It seems to me like block cracks are more related to heat than seizing. My plan was to build a 4.4/4.6 stroker out of it, but now I'm searching for a used engine to fully factory rebuild for peace of mind.

Not supercharged (in fact 100% stock), 141k miles, with LiquiMoly 10W60 changed every 5K.

RocketyMan wrote

Maybe it's just me and/or the lighting, but all the BE conrod bearings look to show or are starting to show some copper coming through.

Can you take another picture of the BE bearings you pulled out with all the oil wiped off clean? This is very interesting.

We didn't manage to get any close ups before they got out of order, but I can get a photo of the bearings at some point regardless. They were certainly not perfect, but no excessive (well...compared to a regular s65) signs of wear apart from Number 5 which looked a little unhappy.

Signature Wheel BMW wrote

The good news is your motor wasn't seized so crank and block could be saved. Once motor is seized, block has micro cracks. If crank is destroyed, just go with VAC 4.4 kit or ask Carbahn for used cranks.

Were you supercharged? What oil model and weight have you been running before and now? For my own personal data logs of S65 engine failure and oil brand.

My chassis has gone through 2 motors on track. One the rod put a hole through the block, the other mains seized up. Once mains give, it will fill oil passages with glitter blocking oil flow to RBs. So we may never know how many motors reported failure due to RBs were caused by Mains.

WDYM? His block is cracked. And so not sure how the block could be saved. The oil feed would be compromised at main #1.

Not saying it's impossible, but I haven't ever seen/heard of someone welding up oil galleys on aluminum blocks before.

JonOhh wrote

We didn't manage to get any close ups before they got out of order, but I can get a photo of the bearings at some point regardless. They were certainly not perfect, but no excessive (well...compared to a regular s65) signs of wear apart from Number 5 which looked a little unhappy.

Totally appreciate you sharing your experience and all your pictures, too! Just a close up with all the conrod bearings would be great in good lighting and cleaned off.

ab987 wrote

In my case the block is cracked even though the engine turned over very freely and the mains hadn't spun, pictures in one of the previous posts. It seems to me like block cracks are more related to heat than seizing. My plan was to build a 4.4/4.6 stroker out of it, but now I'm searching for a used engine to fully factory rebuild for peace of mind.

Not supercharged (in fact 100% stock), 141k miles, with LiquiMoly 10W60 changed every 5K.

Ahh, I missed the part where you mentioned the block is cracked. Dang. Was this on track? What oil temps were you seeing?

When I used LM for track, it was touching 280-285F. Probably the hottest oil I've ran.

I’m reading this post and shitting myself! I have 265,XXX on my S65 and this is scary stuff! I wonder who can be relyed on for proper main bearing jobs in LA area? I emailed EAS to see what they offer. Sorry you’re going through this OP. I’ve done RB’s twice and only use BMW 10-60 every 5k but I’ve done nothing for mains.

Signature Wheel BMW wrote

Ahh, I missed the part where you mentioned the block is cracked. Dang. Was this on track? What oil temps were you seeing?

When I used LM for track, it was touching 280-285F. Probably the hottest oil I've ran.

The highest I've ever seen on track is 245F, but it's only been in the winter months. It was also 1000-1500 miles ago that it last saw the track so the actual failure happened afterwards.

Promise I haven't forgotten about the rod bearing pics, I'll clean them up tonight and post some pics. The wear is mildly concerning on 2 cylinders.

Grabbed some decent pictures of the BEv2 rod bearings, man photographing these is tough. Not 100% sure on the order, but trying to match them to the picture I posted before. Note that 1-4 are the passenger bank and 5-8 are the driver bank, front to back (the original bearing picture was front to back, so 1, 5, 2, 6, etc):

#1 spun due to oil starvation from the melted main, pictures above.
#2:

#3:


#4:

#5:


#6:

#7:


#8:


There's some pretty alarming wear on #3 and #7, remember this was 11-12k miles. Seems like the babbit layer took a beating and did its job on the others. None of the "good" bearings were wearing past the second (lead?) layer and seemed to have a fair bit of babbit (silver oxide?) left. Note that they have been dinged up since removal so ignore scratches.

I did measure each clearance with plastigauge, and they were all within 0.0013 and 0.0015 inches which seemed low, but the website mentioned it's more than likely fine. I'm sure with dial/bore gauges and matching clearances a bit better you could achieve better results, but there is certainly wear happening. Can't say for sure how much of it was the metal going through the oil.