[tranck]

So, I had my car in yesterday to get a new Waste Gate Actuator as the old one was throwing a Drive Train Malfunction error message on my iDrive screen.

While at this very good independent shop, the owner informed me that he's starting to see spun rod bearings on n55 engines at about one per month now.

He said that they involved all n55 engines not just the ones in the n55's of the 2016-2018 M2's.

I change the oil on average every 4K miles and don't beat on the car nor track it - he said that I should be fine although my car now has over 60K miles on it.

My limited understanding of the M2 n55 engine vs. others is that the M2's version has a forged crank and upgraded rod bearings as well as a better oil pump.

Is this all ^^^ correct (especially the better rod bearings)?

The guy kinda freaked me out yesterday because I spun a rod bearing in my old e39 M5 and sure as heck don't want this happening to my M2?

If anyone could clarify exactly the upgraded internals of the n55's in M2's vs. other n55's and maybe put my mind at ease, it would be greatly appreciated.

Thanks in advance.

[PackPride85]

Originally Posted by tranck

So, I had my car in yesterday to get a new Waste Gate Actuator as the old one was throwing a Drive Train Malfunction error message on my iDrive screen.

While at this very good independent shop, the owner informed me that he's starting to see spun rod bearings on n55 engines at about one per month now.

He said that they involved all n55 engines not just the ones in the n55's of the 2016-2018 M2's.

I change the oil on average every 4K miles and don't beat on the car nor track it - he said that I should be fine although my car now has over 60K miles on it.

My limited understanding of the M2 n55 engine vs. others is that the M2's version has a forged crank and upgraded rod bearings as well as a better oil pump.

Is this all ^^^ correct (especially the better rod bearings)?

The guy kinda freaked me out yesterday because I spun a rod bearing in my old e39 M5 and sure as heck don't want this happening to my M2?

If anyone could clarify exactly the upgraded internals of the n55's in M2's vs. other n55's and maybe put my mind at ease, it would be greatly appreciated.

Thanks in advance.

Pretty sure the rod bearings in the M2 N55 are the same. Main crank bearings were changed to the S55 ones.

[Endeav]

Rod bearing failure in the non-M N55's were a lot in part due to the owners tracking them and having periods of oil starvation under braking / hard cornering. The M2 oil pan / sump design fixes these issues.

Not saying all failures were related to this, but a large percentage of them seemed to be.

Originally Posted by PackPride85

Pretty sure the rod bearings in the M2 N55 are the same. Main crank bearings were changed to the S55 ones.

This seems to be correct just based on part number searches on RealOEM.

[nismoman]

as stated above the m2 uses the same oil pan and pickup/pumps as the s55 hense the whole part number fiasco for oil filter kits for m2 n55 engines.

[K8_M235i]

A lot of n55 rod bearing wear has to do with cold start operation. BMW changed their recommended oil from 5w30 to 0w30 because of this.

I plan on getting my rod bearings in my m235 replaced when my car is out of warranty.

[akkando]

Originally Posted by tranck

So, I had my car in yesterday to get a new Waste Gate Actuator as the old one was throwing a Drive Train Malfunction error message on my iDrive screen.

While at this very good independent shop, the owner informed me that he's starting to see spun rod bearings on n55 engines at about one per month now.

He said that they involved all n55 engines not just the ones in the n55's of the 2016-2018 M2's.

I change the oil on average every 4K miles and don't beat on the car nor track it - he said that I should be fine although my car now has over 60K miles on it.

My limited understanding of the M2 n55 engine vs. others is that the M2's version has a forged crank and upgraded rod bearings as well as a better oil pump.

Is this all ^^^ correct (especially the better rod bearings)?

The guy kinda freaked me out yesterday because I spun a rod bearing in my old e39 M5 and sure as heck don't want this happening to my M2?

If anyone could clarify exactly the upgraded internals of the n55's in M2's vs. other n55's and maybe put my mind at ease, it would be greatly appreciated.

Thanks in advance.

They sold so many n55 engines over like the last 8 years. It's got to be a very very low chance in general on the n55. As far as the m2 version of n55 I couldn't say if it's more or less likely to happen than other versions. Do we even know why they spin on the handful of n55 engines that have had an issue?

[Tes]

From my research before buying my 2018 M2 is that this issue can occur but it is still rare. I've heard if you really want to have a peace of mind, switch over to the S55's oil pan, it is a direct bolt on and completely removes all the issues with oil starvation. When my car gets older if the oil pan gasket ever leaks, I plan to switch over to the S55's oil pan.

[F87source]

Originally Posted by Tes

From my research before buying my 2018 M2 is that this issue can occur but it is still rare. I've heard if you really want to have a peace of mind, switch over to the S55's oil pan, it is a direct bolt on and completely removes all the issues with oil starvation. When my car gets older if the oil pan gasket ever leaks, I plan to switch over to the S55's oil pan.

The m2 already has the S55 baffled oil pan, and dual oil pumps (secondary pump is to move oil back towards the pick up under hard lateral acceleration or braking) making it a quasi dry sump.

So no need to retrofit anything for the N55 m2, it is ready to hit the track without any issues.


That being said the m2's sump along with the S55's can handle 1.2G sustained, alot from my data log review I have also not seen any issue with quick turns causing G forces to hit 1.7. But if you some how plan to hit over 1.2 G for long periods of time then you should opt for the S55 CS sump which can handle 1.4 G sustained due to its increased oil capacity. Or get an accusump.





Also bmw updated the N55 rod bearings in 2014 as shown by the p/n change when they switched to the F series chassis and introduced the m235i and 435i. The issues with rod bearings have not occured since, and those that have occured were due to oil starvation on the track.

[Tes]

Originally Posted by F87source

The m2 already has the S55 baffled oil pan, and dual oil pumps (secondary pump is to move oil back towards the pick up under hard lateral acceleration or braking) making it a quasi dry sump.

So no need to retrofit anything for the N55 m2, it is ready to hit the track without any issues.


That being said the m2's sump along with the S55's can handle 1.2G sustained, alot from my data log review I have also not seen any issue with quick turns causing G forces to hit 1.7. But if you some how plan to hit over 1.2 G for long periods of time then you should opt for the S55 CS sump which can handle 1.4 G sustained due to its increased oil capacity. Or get an accusump.





Also bmw updated the N55 rod bearings in 2014 as shown by the p/n change when they switched to the F series chassis and introduced the m235i and 435i. The issues with rod bearings have not occured since, and those that have occured were due to oil starvation on the track.

That's good to know! the M2 just getting better and better XD thanks for the info.

[F87source]

Originally Posted by Tes

That's good to know! the M2 just getting better and better XD thanks for the info.

No problem!

[chris719]

Yeah, all good posts above. I concur, I followed the E9x forums for years as I nearly bought one on several occasions. The rod bearing issues with those cars is far more prevalent and obvious. There's really never been an S85 or S65 engine torn down with what I would consider pristine rod bearings. The issue is definitely the opposite with N55. They have produced so many N55 engines and they have been around so long now that any widespread problems would be evident.

[///M TOWN]

Originally Posted by chris719

Yeah, all good posts above. I concur, I followed the E9x forums for years as I nearly bought one on several occasions. The rod bearing issues with those cars is far more prevalent and obvious. There's really never been an S85 or S65 engine torn down with what I would consider pristine rod bearings. The issue is definitely the opposite with N55. They have produced so many N55 engines and they have been around so long now that any widespread problems would be evident.

Agreed

Another words....

Don't believe everything that is said, especially a mechanic trying to make a living

[chris719]

Originally Posted by ///M TOWN

Agreed

Another words....

Don't believe everything that is said, especially a mechanic trying to make a living

Yeah, BMW definitely has various issues with some engines (S54, S65, S85, early N63s, N54 etc.), but I feel like N55 is one of the safest bets overall given the massive production volume and number of miles those cars have accumulated.

[F87source]

I had to bring this point I made on one of OP's other threads over to this thread as well because I keep seeing alot of poor info online that I do not think properly represents the whole issue of bearing failures (and some bad advice that really kills me inside leading to the reason why I stay off of social media). So here we go.

People keep saying the n55 bearings fail easily, this is true on the pre 2014 bearing update by bmw on the n55, the new bearings are shared by the S55 which does not see the same bearing failure issues (the oiling system as discussed in point 1). So why does the n55 still suffer bearing failure? Well these are the reasons why:

1) The sump on a standard F series n55 is garbage, it has little to no baffling and under high G forcing including braking, the oil pick up will suck up air resulting in oil pressure drops. Luckily for us BMW gave us OG m2 owners an upgrade sump from the S55. This leads to bearing failures over time. So all of the owners who track their car hard, do alot of drifting on the streets, do sustained donuts in the parking lot etc are more likely to suffer from this if the G forces get high enough to starve the oil pick up, and it does not take much to do it (well below the 1G mark). This result in bearing failure which mistakenly gets blamed on the poor bearing design despite that not being the case, also people do not recognize G force induced oil starvation because they think all bmw's are track ready but this is not the case unless you own a bmw with an upgraded sump system like on the n55 m2 and s55 powered cars (I cannot say all M's because the 1M gets the standard n54 sump which is pretty crap as well). BTW iirc left hand turns are most problematic because of the way the engine is tilted and thus the sump is made like a wedge.

2) Abuse/neglect: this consists of driving the car hard before oil temps have warmed up to the operating temp which should be 90ºC. This means oil is too thick resulting in poor lubrication to the bearings. Also infrequent oil changes are a huge killer to bmw's, especially when owners follow bmw's 15,000 km oil change interval resulting in severe oil degradation and loss of alot of the tbn and additives in oil meaning it cannot provide sufficient protection and anti wear characteristics.

3) Oil filter housing gasket: people change these gaskets at higher mileage, this induces air bubbles in the oil loop that must be purged by priming the oil system. This is a step that is skipped so frequently on OFHG jobs and results in failures of the rod bearings literally within a couple of thousand of miles after the service, and again is blamed on the bearings themselves when it is not the case. I literally just watched a youtube video about a guy complaining about bearing failures and in the comments he said he forgot to prime the oil system and the bearings went 10k miles later. This is literally how rumours of bad bearings gets started. Also anything in regards to the oil lines being removed must result in oil system priming, such as oil cooler jobs, oil thermostat delete plates, oil lines, turbos etc. And yet no one ever does this step. PS: if priming the oil system disconnect the injectors and coils, do not pull the LPFP fuse, I always hear bad advice about pulling the LPFP fuse and letting the fuel system go dry. This is bad because what lubricates the HPFP? That's right gasoline, and what cannot go to the HPFP if the LPFP fuse is pulled? That's right gasoline.... Do what the bmw tis says, and that is pull the fuel injector connectors, stop trying to take short cuts please.

4) Use good quality oil when tracking and of the proper weight, thicker does not mean better, and please stop referring to the stock bmw twin power turbo oil as "water" shell did a fricken phenomenal job on this oil for bmw and it is EXTREMELY STOUT according to its reported 3.5 hths rating which is HIGH for a 30 weight. Especially when liquimoly (a popular bmw oil, but in the oil world it is not so favorable and only popular due to its name, hence why I do not like it) LEICHTLAUF HIGH TECH SAE 5W-40 has only a 3.5 hths rating which is extremely low for a 40 weight. So yeah this is a lesson for all you guys who only see oil weight, so again another reason why you must think critically when listening to advice about oil I was also confused before I joined BOITOG. Also this is a lesson about not judging oil by its price expensive oils are not necessarily better than cheaper oils, pennzoil platnium euro 5w40 has a GTL base which makes it an extremely clean oil with a NOACK of 6% which is less than the 10% of liquinoly LEICHTLAUF HIGH TECH SAE 5W-40 and has an HTHS of 3.8 which is higher than liquimoly so overall better specs for pennzoil, and it only costs $30 CAD for a 5L jug when on sale at Canadian tire so like almost 1/3 the price. Anyways the point of running good quality oil is because these cars run HOT on the track so you want the best protection you can get for your bearings, and you do not want to run oils that are too thick so you don't run into lubrication issues.


So overall before you guys get scared about every rod bearing post out there I would suggest asking the poster about the points I listed above first, more often than not one of the above will have been the cause of failure not because of the bearing itself. Also note, bears are a wearing part, they do naturally fail over time but not at extremely low mileages so no real need to panick about replacing it so soon it is not a huge deal like it was on the E9X m3.

[VisualEcho]

TRACK TRACK TRACK TRACK

That's all you need to read.

If you don't track your M2 you don't need to know any of this stuff, but if you do, you've gotta' be an expert.

[Pray for Mojo]

I've seen a handful of newer N55s, M235is ect spin bearings. Most seemed to be 2nd owners with little to no service history outside the 10k mile oil changes through BMW. The track examples are pretty easy to find, there's one on 2addicts right now.

I don't beat on my car too much so my biggest concern is cold start wear in the winter. Running the 0W-30 twin power in winter seems to do the trick. My car came from factory with 5W-30 and I ran that for the first 5 years, but the 0W cleaned up a lifter tick I had at cold start so it seems to lubricate better.

Unless you live somewhere with high temperatures almost year round I wouldn't run the 40 oils. BMW seems to be trending towards lighter weights on newer cars, our B58 X3 takes 0W-20 from factory.

Any work on the oiling system seems to increase the risk of spun bearings, whether its from an air bubble in the oil system or debris from the OFHG is unknown. I wouldn't DIY these jobs if you haven't modified your car, if something happens right after the work you could probably get the BMW/dealer to goodwill a new engine vs the fight over tunes.

[F87source]

Originally Posted by VisualEcho

TRACK TRACK TRACK TRACK

That's all you need to read.

If you don't track your M2 you don't need to know any of this stuff, but if you do, you've gotta' be an expert.

Well not always just track use but it is a big factor.

[F87source]

Originally Posted by Pray for Mojo

I've seen a handful of newer N55s, M235is ect spin bearings. Most seemed to be 2nd owners with little to no service history outside the 10k mile oil changes through BMW. The track examples are pretty easy to find, there's one on 2addicts right now.

I don't beat on my car too much so my biggest concern is cold start wear in the winter. Running the 0W-30 twin power in winter seems to do the trick. My car came from factory with 5W-30 and I ran that for the first 5 years, but the 0W cleaned up a lifter tick I had at cold start so it seems to lubricate better.

Unless you live somewhere with high temperatures almost year round I wouldn't run the 40 oils. BMW seems to be trending towards lighter weights on newer cars, our B58 X3 takes 0W-20 from factory.

Any work on the oiling system seems to increase the risk of spun bearings, whether its from an air bubble in the oil system or debris from the OFHG is unknown. I wouldn't DIY these jobs if you haven't modified your car, if something happens right after the work you could probably get the BMW/dealer to goodwill a new engine vs the fight over tunes.

Yeah run a 0w if you daily your car in the winter especially if you're in Calgary.


Well if your ofhg is leaking you need to get it addressed, or even worse problems can occur in regards to the serpentine belt.


But doing it yourself isn't a bad thing if you follow protocol from ista. Just clean the surrounding area before doing it and you should be fine in regards to foreign debris. There have been plenty of successful diys, and the ones who have failed didn't follow the steps and took short cuts.

[VisualEcho]

Originally Posted by F87source

Well not always just track use but it is a big factor.

I meant to say that, the car is really a half-street, half-track car, if you look at the BMW marketing. But for those of us that use it for a 2.7-mile commute, and the weekly spirited back-road blast, we will never have an issue.

[F87source]

Originally Posted by VisualEcho

I meant to say that, the car is really a half-street, half-track car, if you look at the BMW marketing. But for those of us that use it for a 2.7-mile commute, and the weekly spirited back-road blast, we will never have an issue.

True.

But you can definitely track it hard and also have no issues, but you have to do alot more maintence than just dailying it and spirited driving on weekends.

[tranck]

I haven't been on the board in a few days and hopefully, I didn't freak people out w/ my OP.

I *did* do an "OO!" when I saw that there had been additional responses on this thread though.

Long and short of it - My 2018 now has 64K miles on it - 61K by me and I'm trading it in on a new 2021 Subaru CrossTrek Limited this Monday.

At my mileage, I'm just concerned that maintaining the car will put me in the poor house.

The Subaru guy said that my car was flawless (have a front end wrap) after he drove it and we agreed on $31.5K for my car. AW - manual, Exec pkg.

With over 3K off MSRP and more than 1K under invoice for the Subaru, I'm making the jump.

It's been real guys and I could thank a lot of members here but in particular - a shout out to F87source.

He's been very helpful to me through PM's as well as all of his posts here.

I wish everyone the very best of luck with your cars!

Take care All.

[PackPride85]

Originally Posted by tranck

I haven't been on the board in a few days and hopefully, I didn't freak people out w/ my OP.

I *did* do an "OO!" when I saw that there had been additional responses on this thread though.

Long and short of it - My 2018 now has 64K miles on it - 61K by me and I'm trading it in on a new 2021 Subaru CrossTrek Limited this Monday.

At my mileage, I'm just concerned that maintaining the car will put me in the poor house.

The Subaru guy said that my car was flawless (have a front end wrap) after he drove it and we agreed on $31.5K for my car. AW - manual, Exec pkg.

With over 3K off MSRP and more than 1K under invoice for the Subaru, I'm making the jump.

It's been real guys and I could thank a lot of members here but in particular - a shout out to F87source.

He's been very helpful to me through PM's as well as all of his posts here.

I wish everyone the very best of luck with your cars!

Take care All.

Kind of funny you're going to Subaru who is known to probably have the highest percentage of rod bearing failures of any company lol. Although that was due to them sticking with the flawed EJ engines for so long. The new FB series in the crosstek is pretty stout though.