Seized N52 main bearing, rods bearings upgraded previously

[4JawChuck]

Recently had my 2013 128i 100 000kms seize solid on a cold start (-24C), the day before a loud squealing was heard at startup which sounded like a bad idler pulley but in hindsight was obviously the first sign the bearing was being bitten.

In addition found massive carbon buildup in all cylinders which was traced to leaking injectors.

Anyone else have this happen?

Here’s a pic after the engine was removed in my garage. Looks like those aluminum/tin bearings don’t hold up even on the main crank journals. The trimetal replacement rod bearings look mint and were obviously replaced at some point prior to purchase a year ago.

[4JawChuck]

Luckily it seized on a cold start and only ran for a few seconds before seizing solid, some aluminum in the oil filter which prompted the tear down.

Crankshaft is undamaged and I managed to get the pistons out without damaging the bores that a polish wont take out.

Kinda pissed that this an issue, I’ve seen plenty of rod bearings in my hotrodding hobby and never spun a crank bearing that wasn’t a result of low oil pressure or low level.

It’s a six speed car that’s my daily driver and hasn’t been driven hard since the snow fell this year.

All the mains look wiped of their tin coating in areas.

[Almuliman]

Yikes. (Nothing else to say, but we don't have nuanced reactions, only "Appreciate", which I'm definitely not.)

Edit: Any idea why the surviving bearings were replaced? Can't say I've heard of that on an N52 before.

[4JawChuck]

Since I am not the original owner and the previous owner is in another province it would be impossible to say when the rod bearings were done.

This was with Castrol Syntec in the recommended grade and full according to the sensor and amount that drained out. Oil wasn’t contaminated with fuel but plenty of AL particles when I drained it for removal.

To say I am gob smacked over an engine seizing after starting on a cold day when it was plugged in with an oil heater pad just blows me away.

Did some research and most authorities don’t recommend these kind of bearing for anything but low performance applications.

[Almuliman]

Are you saying the bearings that *didn't* hold up are OE? I don't know enough to know if "aluminum/tin" would be OE or not...

[4JawChuck]

OEM is steel backer,, aluminum overlay with Tin coating, they made the change to eliminate lead used in the bearings.

The non-OE rodbearings are traditional Trimetal bearings, steel back with copper overlay and lead coating. These are not original, I seen signs when removing the engine that the cradle had been dropped before...they couldn't get the coolant hose off the subframe with the torx fasteners under the balancer so they cut the plastic mounts off with what looks like a knife, missing bolt on the waterpump and broken bolt on the head.

I see the M3 S65 guys who are facing the same issue have filed a class action, this is engineering negligence if you ask me.

[Blau]

I'd stop stripping this engine down unless you're going to do something interesting to it. The n52 can be had for cheap in many junk yards. Start with a running one and then do all of the mods you want. It isnt going to be less expensive to save your current engine.

[4JawChuck]

I weighed that option, but the new engine will have the same weak bearings etc. I’ve noticed a number of BMWs come up for sale for similar issues particularly in the colder provinces here. Obviously a warmer weather car if the main bearing can’t survive plugged in with warm oil.

For the price of the parts and tools I’ve already started tearing it apart and ordering parts to do a minor rebuild.

Anything I’ve seen for sale with similar mileage is located in the US and shipping it including purchase price is close to 5K. I can rebuild for about $1500 in parts plus my labor.

If I didn’t hotrod engines for fun and have four engine stands in my garage for these activities I would have paid my way out of it and just swapped the engine.

From research it looks like without trace amounts of ZDDP and Moly in the oil this will be the fate of every aluminum bearing engine out there (the tin coating forms a barrier with those two additives).

All the mains had signs of wiping, unheard of in todays world and a sign this is not the bearing to use in a performance car of any kind.

Head and block is fully disassembled and head is being ported now, just need to decide if I want to unshroud that one intake port which is obviously meant for emission control. Only minor porting required on the exhaust side, intake side is CNC ported and as good as you can make except for the shroud around the leading intake valve on the chamber side.

[Olgeezer1]

Yikes! Never heard of an N52 doing this. With rod bearings previously changed, have to wonder what else this engine has been subjected to. Any LL01 approved oil should have the necessary zinc/moly. I'm currently using Pennzoil Platinum Euro 5/40 ( made by Shell Europe, sold there as Shell Helix ) which shows good but not excessive zinc and LL01 approval. Well , with a rebuild you're going to know exactly what you've got and a chance to source the best components. Makes me glad I store my car in winter.

[4JawChuck]

Interior of the motor was spotless, have to say previous owner took care of it that way...very regular oil changes.

Clutch looked new, flywheel still has factory machining marks and looks original, interior mint etc. I'll post a picture from my phone, got it a year ago with 75000kms.

[4JawChuck]

2013 128i SE, 6 speed.

[Almuliman]

An iS? Never heard of an SE before, but those, I believe, are iS wheels. OTOH, I haven't seen a white grill before either. Nice looking 1er.

[4JawChuck]

I was a spray painter in a past life so I’m a sucker for pearl paint, looks greyish silver at sunset.

It’s got all the MSport suspension and goodies except for the seats which was a ridiculous priced option.

Originally a Quebec car, now in Manitoba. Thought this model was super rare but seen another just like it a couple months ago.

There is a thread here on this model, lifestyle edition or LE I guess.

[Almuliman]

Ah, right, CA car. Not an iS with the N52, but a sweet looking car.

[IamFODI]

S65 owner here.

Seeing a familiar pattern in this thread:

1. Stock rod bearings replaced with aftermarket
2. Engine seizes/blows at some point later
3. Rod bearings look great, mains are trashed

In our world, this is often taken as evidence that the mains caused the failure, and boy-howdy aren't we glad we put those aftermarket rod bearings in because at least they did their job.

I'm not so sure. The bottom end is a system, and you can't mess with one part without potentially implicating another part. E.g., per a discussion with a powertrain engineer whose career was in failure analysis, changes at the rod bearings can affect oil pressure in the mains in some regimes. Maybe best to leave it there so as not to get into speculation.

Either way, count me among those who aren't shocked the mains let go in the engine in this thread. If someone's been in the bottom end for unknown reasons, it's a roll of the dice – especially when aftermarket parts are involved.

FWIW: the S65 started out using leaded trimetal rod bearings, like what the aftermarket says is best. It started switching to lead-free rod bearings in 2010. The lead-free bearings are also trimetal, just with no lead; the top layer is some kind of aluminum/tin alloy. For a long time it was assumed that the lead-free bearings didn't fare any better than the old ones because they appeared to show wear down to the copper. However, that turned out to be superficial discoloration that goes away with light sanding. AFAIK, we have yet to see a single case of actual copper being exposed on the lead-free bearings. There have been failures, but those are extremely rare and mostly at lower miles, which could just as easily suggest defects, assembly errors, or abuse. Sharp contrast with the earlier leaded bearings, which regularly wore through to copper. So, at least in S65 land, it seems like the aluminum/tin bearings fare much better than the leaded ones did. Makes sense as aluminum/tin bearing alloys, while still much softer than the crank, tend to be much harder than leaded bearing alloys.

Aftermarket rod bearings often look even better in the S65. But again, with so many engine failures being chalked up to other causes (abuse, "the mains went first", etc.) and therefore ignored, we don't actually know if aftermarket rod bearings are actually allowing engines to live longer – which I'm sure we'd all agree is what we're really going for.

Can't say how anything from S65 land relates to this case; just pointing out that the S65 community may have given too much traction to the idea that the aftermarket can spec a rod bearing better than BMW can. Worth keeping in mind when looking at our experience with rod bearings.

[4JawChuck]

Honestly what the two separate issues illustrate is BMW fails at designing bearing systems.

There's an X3 for sale in my area, same issue seized on cold start. I would link the ad but not trying to sell anything here. No two cases are the same but the brand name is consistent.

Regardless I've been dealt a hand that I can fix, the engine will be rebuilt to proper bearing specs with the Clevite tri metal bearing running the recommended clearances they give...not BMW.

Going to start with having the crank micropolished, looks fine with just embedded aluminum on a few journals. Almost all of the mains were in the process of being wiped, to my eye and micrometer looks like too little clearance...but I haven't put a bore gage in it yet.

Head, block, crank and bed plate are going in for work at the machinist tomorrow, he will ultrasonic clean the block and I will hone the block here at home. Anyone got a small jar of AN30 paste kicking around, willing to pay for shipping!

Here some pics of the head porting finished.

[4JawChuck]

More evidence BMW does no know how to do bearing journals, how much you want to bet half of the cars out there have this same cracked bedplate…especially up north.

[Ric in RVA]

Originally Posted by 4JawChuck

More evidence BMW does no know how to do bearing journals, how much you want to bet half of the cars out there have this same cracked bedplate…especially up north.

That is disheartening....

Block is now junk and clearly not designed for any power to be put through it.