[TZANIDO777]

Here is what my bearings looked like after roughly 34k miles.

If you're wondering why cylinder 2 is empty, its because the rod bearings on that cylinder seized to the crankshaft. When I pulled the cap off cylinder 2 all the bearing material had either welded itself to the crankshaft or made its way to my oil filter.

I also attached my previous 3 blackstone reports.

[Pladi]

Originally Posted by TZANIDO777

Here is what my bearings looked like after roughly 34k miles.

If you're wondering why cylinder 2 is empty, its because the rod bearings on that cylinder seized to the crankshaft. When I pulled the cap off cylinder 2 all the bearing material had either welded itself to the crankshaft or made its way to my oil filter.

I also attached my previous 3 blackstone reports.

wow just wow.. this is getting better and better. Were u tuned ? just saw u tracked

will we ever see normal wear on N55 bearings for the low mileage ?

I am leaning towards putting my car for sale in the spring..

[TZANIDO777]

Originally Posted by Pladi

wow just wow.. this is getting better and better. Were u tuned ? just saw u tracked

will we ever see normal wear on N55 bearings for the low mileage ?

I am leaning towards putting my car for sale in the spring..

Yes, full bolt on tuned with MHD stage 2 OTS map.

I am also running full slicks so that does not help with oil starvation.

[Demz760]

Originally Posted by YuvinW

Last oil change was Mobil1 0w40, completely stock motor and the build date was 2011-09-21.

Are there any shops around the San Francisco/Bay Area that can do this work? I drove this car from Toronto to San Francisco at the start of the year.

My build date is 2011-09-28, 7 days later...

How many miles on the car? I fear my car will face the same fate.

[bbnks2]

Originally Posted by Pladi

From all those threads i only see one case. Most people on those threads talk about our threads lol. And confirm that there arnt any cases for F30. Like more rare. Unlike here.

Actually F-series forums is where tons of videos popped up first when those cars were basically brand new and people freaked out... These posts have been coming and going for years and they exist on every car forum in existence: EJ, VQ, LSx, B and K series Honda engines, pretty much every "tuner" engine where enthusiasts gather on forums there is a massive rod bearing thread.

[Pladi]

Originally Posted by bbnks2

Actually F-series forums is where tons of videos popped up first when those cars were basically brand new and people freaked out... These posts have been coming and going for years and they exist on every car forum in existence: EJ, VQ, LSx, B series Honda engines, pretty much every "tuner" engine where enthusiasts gather on forums there is a massive rod bearing thread.

Sorry mate i just dont believe it lol. BMW seems to be pretty bad when it comes to rod bearing issues, from v8 to V10 to inline 6. Too many rod bearing issues. I cant think of any manufacturer that has multiple engine lines with such fundamental engine problem. It spans accross like over a decade and multiple engines... Thats effed

So yeah i dont believe it

[9krpmrx8]

^ that is an episode of oil starvation, not a rod bearing issue. But yeah every engine has a failure rate, my buddies SS Camaro thru a rod a week after he drove it off the lot.

[Pladi]

Originally Posted by 9krpmrx8

^ that is an episode of oil starvation, not a rod bearing issue. But yeah every engine has a failure rate, my buddies SS Camaro thru a rod a week after he drove it off the lot.

Ahhhh the expert already identified why hahahahah. Ur a funny guy man. Ur so good. U know right away what happened.

[9krpmrx8]

Originally Posted by Pladi

Ahhhh the expert already identified why hahahahah. Ur a funny guy man. Ur so good. U know right away what happened.

Thanks man, I really appreciate it. If you need help with anything else just let me know.

[Pladi]

Originally Posted by 9krpmrx8

Thanks man, I really appreciate it. If you need help with anything else just let me know.

Dont u worry will have more rod bearing fails

[Welcome to NBA Jam]

Rod knock in the N55 is sounding more and more like a sudden problem with an unknown direct cause, and not an excess-wear-over-time problem.

[bbnks2]

Originally Posted by Welcome to NBA Jam

Rod knock in the N55 is sounding more and more like a sudden problem with an unknown direct cause, and not an excess-wear-over-time problem.

Yes, when you're at the track with r-comp tires in a street car (referring to post #133) with a fairly shitty oil pan and relatively small oil capacity sudden rod bearing failure happens. Pickup runs dry and rods ride on metal instead of oil. It happened to me and I knew it was inevitable before it finally did.

What other "sudden failure" cases are you referring to? The OFHG failures? Yes, I'd agree that those cases are also sudden failure that is hard to pin-point the cause of. It's not an N55 specific issue by any means though and the very BMW tech who posted the "priming procedure" bulletin stated that it applies to all makes and models that require that service.

Otherwise wear over time, but in excessive rates, is exactly what you're seeing in all of these other threads. Unless, I missed something? Cause of the wear is what needs figuring out.

[9krpmrx8]

Originally Posted by Pladi

Dont u worry will have more rod bearing fails

Yeah, all of them wear out over time genius.

[Pladi]

Originally Posted by 9krpmrx8

Yeah, all of them wear out over time genius.

then why do we have these threads genius ?

[Welcome to NBA Jam]

Originally Posted by bbnks2

Yes, when you're at the track with r-comp tires in a street car (referring to post #133) with a fairly shitty oil pan and relatively small oil capacity sudden rod bearing failure happens. Pickup runs dry and rods ride on metal instead of oil. It happened to me and I knew it was inevitable before it finally did.

What other "sudden failure" cases are you referring to? The OFHG failures? Yes, I'd agree that those cases are also sudden failure that is hard to pin-point the cause of. It's not an N55 specific issue by any means though and the very BMW tech who posted the "priming procedure" bulletin stated that it applies to all makes and models that require that service.

Otherwise wear over time, but in excessive rates, is exactly what you're seeing in all of these other threads. Unless, I missed something? Cause of the wear is what needs figuring out.

All of the above. There have been reports so far of people having good oil analyses with a failure soon after (such as this one), and people who open their oil filter to find a noticeable amount of metal shavings that were not there in their previous oil change. If it was a slow wear over time, wouldn't we expect to find an elevated level of metal detectable over multiple oil analysis rather than a sudden increase to the point that it metal shavings can be readily seen by the naked eye in an oil filter? Or perhaps it wears down to a point and then the wear increases exponentially due to the changes in clearance, but I don't really know anything about the typical wear and failure patterns of a rod bearing.

I'd also like to know if there is one particular bearing that is wearing more than the others in all of these cases. There are so many data points that need to be captured

[9krpmrx8]

Originally Posted by Pladi

then why do we have these threads genius ?

Because on the internet, people love to argue and speculate about mostly non issues. Only here is a less than 1% failure rate a problem or issue at all.

Oh no but because some dickhead has an opinion and heard from a friend that N55 engines fail all the time, we are supposed to see every failure as some evidence of a design problem with the engine. It's like MMP saying N55's are blowing up like crazy on FB because they would like to have people thinking they are rebuilding several N5X engines a week, yet the only evidence of their builds I see is customers complaining about them failing. But yet they offer zero data because they are liars.

The sky is falling, the sky is falling.

[xxMike61]

Originally Posted by Welcome to NBA Jam

All of the above. There have been reports so far of people having good oil analyses with a failure soon after (such as this one), and people who open their oil filter to find a noticeable amount of metal shavings that were not there in their previous oil change. If it was a slow wear over time, wouldn't we expect to find an elevated level of metal detectable over multiple oil analysis rather than a sudden increase to the point that it metal shavings can be readily seen by the naked eye in an oil filter? Or perhaps it wears down to a point and then the wear increases exponentially due to the changes in clearance, but I don't really know anything about the typical wear and failure patterns of a rod bearing.

I'd also like to know if there is one particular bearing that is wearing more than the others in all of these cases. There are so many data points that need to be captured

On the first oil analysis he has 65 iron on 7k miles, that doesn't really seem great. I've been doing ~5k intervals and never seen iron go over 30. Maybe oil quality rapidly falls off after 5k? Of course how you're driving matters too

[bbnks2]

Originally Posted by Welcome to NBA Jam

All of the above. There have been reports so far of people having good oil analyses with a failure soon after (such as this one), and people who open their oil filter to find a noticeable amount of metal shavings that were not there in their previous oil change. If it was a slow wear over time, wouldn't we expect to find an elevated level of metal detectable over multiple oil analysis rather than a sudden increase to the point that it metal shavings can be readily seen by the naked eye in an oil filter? Or perhaps it wears down to a point and then the wear increases exponentially due to the changes in clearance, but I don't really know anything about the typical wear and failure patterns of a rod bearing.

I'd also like to know if there is one particular bearing that is wearing more than the others in all of these cases. There are so many data points that need to be captured

What "case" are you referencing? If you're talking about post #133 then you need to consider that he was on a race track running slicks. completely different than OP who tore down his engine and found some scuffed bearings. Sudden failure on track with torn up bearings like that points to oil starvation. Happened to my car too, unfortunately. Even the M cars oiling system is only rated up to 1.2/1.3 G?.

[Bours]

I had a rod bearing failure and i rebuilt the engine.....there are a few ppl in my area with n55s that had a rod bearing failure also....we were all tuned for a certain amount and of time and take our oil intervals very seriously....

it seems to be more common than people think,,,its just not everybody comes online to post about it !

[Ozzie335i]

Bours, how long has it been since the rebuild? And, how much did it cost you?

[YuvinW]

Originally Posted by YuvinW

I fear that I may also have rod bearing noise on my N55 (2011 335xi, 142k miles). I do hear a knocking when around 2k RPM.

I've got an oil analysis kit on the way and I'm not sure if I should driving the car in the meantime.

If it is because of the rod bearings, what would I be able to do? Could I get away with replacement of the bearings or would I need a new motor?

Thanks!

Just to provide an update on this, I got my oil analysis back. The oil I was using was Mobil1 0w40 and I took this sample when I changed over to BMW 0w30.

It looks promising in terms of the relatively low amount of metal found, so I will try to find what else could be causing the noise I hear starting by changing the belt, tensioner and pulleys. I'll also keep doing these oil analysis to see how things change over time.

[TZANIDO777]

Bearings out of a used donor engine that I decided to replace with WPC coated OEM bearings since I still have it on the stand.

Car had 55K miles and oil analysis report came back good from some oil I could scavenge that was still in the pan when I opened it. (better than nothing)