[LoganN55]

So I'm sure everyone is tired of hearing about n55s and their rod bearings. I recently bought a n55 car and it spun a bearing within a week. But the question is why? Everyone always says "the ewg n55 barely ever spin bearings", so that raises the question, why do the pwg cars have more common failure? There has to be something updated right? And if anyone has noticed, 2011 cars spin more bearings than any other. Why has nobody went into this? What was changed? If the motors are almost the same then why is it so rare on the ewg cars? I need answers people! I have heard one thing on the vanos cam phaser bolts backing out and causing a low pressure zone because of the newly created volume, but is there any proof behind that? I've heard the newer cars come with different bolts to fix this. But I can't be sure that it is what causes the issue. Why does everyone seem to walk around this blindly? If it is such a common issue on the pwg(especially the 2011) then why have no techs cracked down on it? I feel like if I rebuild my motor that I'm just going to spin another bearing because of the motor being a 2011 with a obviously flawed design.

[B-Buster]

Plenty has been written about this topic, based on your post it does not seem that you really read into this matter. There is plenty of info and teardown video's out there. It's the same as stating every N63 is doomed, skipping the fact that throughout the years engines get updates.

Different bearings were used in later N55s iirc, early production years received a recall regarding the Vanos bolts so that's mostly fixed by now.

All through the range the BMW oil interval is stupid long which does not help, and then you have the way the car is driven by its owner(s).

I never see someone combine the fact that the wormwheel of the Vanos motor eats away the teeth of the eccentric shaft, causing metal to go through the engine and possibly cause harm.

However it's all assumptions on what goes wrong, if there was a clear technical issue on the N55 that makes it spin bearings this was known for a long time by now.

Don't forget this is a mass product, based on the total amount of cars equipped with the N55's it's a small percentage that has problems. Add to that it's usually a sporty model so it probably wasn't mainly grandma who operated the vehicle.

[LoganN55]

Originally Posted by B-Buster

Plenty has been written about this topic, based on your post it does not seem that you really read into this matter. There is plenty of info and teardown video's out there. It's the same as stating every N63 is doomed, skipping the fact that throughout the years engines get updates.

Different bearings were used in later N55s iirc, early production years received a recall regarding the Vanos bolts so that's mostly fixed by now.

All through the range the BMW oil interval is stupid long which does not help, and then you have the way the car is driven by its owner(s).

I never see someone combine the fact that the wormwheel of the Vanos motor eats away the teeth of the eccentric shaft, causing metal to go through the engine and possibly cause harm.

However it's all assumptions on what goes wrong, if there was a clear technical issue on the N55 that makes it spin bearings this was known for a long time by now.

Don't forget this is a mass product, based on the total amount of cars equipped with the N55's it's a small percentage that has problems. Add to that it's usually a sporty model so it probably wasn't mainly grandma who operated the vehicle.

Every single post I see has people arguing about the information that you stated. Some agrue that it wrong and some argue its right. So how am I suppose to get any good information off of that if people just argue back and forth on info that seems to have no base in tsb or anything? I have done tons of reading on this. Especially after i spun my bearing after a week of ownership. And yes my car was owned by someone who took care of it, and did oil changes before the interval. So mine wasn't beat on. And almost every N55 owner does rod bearings at some point, correct? Every person that modifies them and wants them to last sure does. That doesn't seem like a small percentage. Especially with most people pulling them and having them scarred up at 100k miles. And another thing, is that a large portion of the percentage base of the failed n55s were in suvs. I don't want to get into a argument over this because that is what others do over the topic, but treating me like I have no base to my information isn't going to help either. I appreciated the response though. I hope after my bearing replacement that my car will provide me with another 50k miles or so.

[B-Buster]

Originally Posted by LoganN55

Every single post I see has people arguing about the information that you stated. Some agrue that it wrong and some argue its right. So how am I suppose to get any good information off of that if people just argue back and forth on info that seems to have no base in tsb or anything?

For starters, don't listen to those who argue.

And yes my car was owned by someone who took care of it, and did oil changes before the interval. So mine wasn't beat on.

Frequent oil changes do not make it not being beat on. Keep eyes on that oil temp gauge and have it nicely warm before getting into power.

And almost every N55 owner does rod bearings at some point, correct?

Is that so? For years it has been one of the most denied service items for most of the N55 owners. Of course with exception of the enthusiasts who go the extra mile. Most owners don't realise this is a thing, lots of cars are unaffected.

And another thing, is that a large portion of the percentage base of the failed n55s were in suvs.

Source? Actual stats?

If you go to the 2-series forum you'll find spun bearings, same with 3-series, 5/6/7 series, X3/4/5. Some caused by not building oil pressure after changing the OFHG, others after spirited driving without a baffled oilpan causing the oilpump to run dry, another one with a failed cooling system so the engine ran hot, etc.

Following this for years now, my conclusion is that there are multiple reasons why this can happen. Mileage varies from low-mileage with spun bearings to early production 300k N55's on original bearings. Now you want a definitive answer as to what goes wrong. If there was a specific issue with the N55 killing those in the numbers you seem to think are failing, there would have been a class action lawsuit (and we in the EU would be f'ed anyways).

I don't want to get into a argument over this because that is what others do over the topic, but treating me like I have no base to my information isn't going to help either.

We can have a discussion based on facts, so far all I read is frustration and an opinion based on input from what you call arguing people which is no base for a discussion.

[ChiltiCoatl89]

I never go past 2500 RPM until I know my N55 is nice and warm, (near 250f) When I crank the engine, I always wait until the RPM drops below 1k and it regulates at around 750-800rpm range before I start my drive, It's cold here in The Great Basin right now and I love my N55, Just want to be precautious and take good care of my Engine and hope I get many many years of enjoyment as I have the last 6 months since I got mine

[e4603]

Originally Posted by B-Buster

Some caused by not building oil pressure after changing the OFHG, others after spirited driving without a baffled oilpan causing the oilpump to run dry, another one with a failed cooling system so the engine ran hot, etc.

@B-Buster is correct. Failure due to not following the oil priming procedure after OFHG and other repairs is documented in a BMW TSB.