[XutvJet]

This isn't false information.

[lens]

That is completely false information.

[MadJonny]

Originally Posted by Jelly_Belly

So, i have an EWG N55 and I spun a rod bearing a couple weeks ago. I wasnt tracking the car however I was merging onto the freeway.

Im found a motor with 15k Miles on the clock and im going to be installing VAC Motorsport bearings and APR head studs.

Unfortunately i have Xdrive so installing the S55 oil pan is not an option. (Althought i am curious if i could install the S55 oil pump and keep the n55 Xdrive Pan)

I highly recommend you guys do your oil changes on time and if you guys ever have to, upgrading the bearings and the oil pan is an absolute must for long term reliability.

Mind you it seems like im an outlier amongst EWG owners.

Xdrive oil sump is poorly designed due to the front driveshaft and maybe the oil was a little bit low. Shame to hear.

[Jelly_Belly]

Woah, sorry i havent posted in a while, been busy with the car.

Lots of replies, i really appreciate everyones inputs

Originally Posted by XutvJet

These motors can handle a lot of abuse and spun rod bearings aren't super common, but I will add these motor are expensive as hell and generally hard to find as the M235 is a rare car in the US and the N55 motor in the M235 is specific as it has a forged crank vs the cast crank found in all other N55s except for the 2016-2018 M2 (forged crank as well). You'll end up spending $8-12K on a used M235 motor assuming you find one. Or you can spend $15K on a remanufactured short block from BMW and spend $5K to install it.

Excellent point, I purchased the used M235i after extensive research because i figured id be better off having forged internals. However on the flip side, once my motor died. It was a huge pain in the ***.

In fact it was such a pain to find an M235i motor, that one of the local shops that services bimmers under warranty. Suggested I have my crankshaft machined and drop in with new bearings, as it would be easier than having to find a new motor. Another shop also suggested sourcing an N55 from a 335i and "just stage one it bro" (real response from a shop, i was shocked )
I respectfully denied both offers/solutions.

The motor i found with 15k miles on the clock ended up costing me 7.8k + shipping and i have to return my old core.

I just got the motor this week so its not in the car yet. im waiting on the VAC motorsport bearings to arrive.

Originally Posted by MadJonny

Xdrive oil sump is poorly designed due to the front driveshaft and maybe the oil was a little bit low. Shame to hear.

So, it turns out that the N55 has a poor oil pan and oil pump design in the first place. this is why in the S55 of the m2, the oil pan was redesigned ( and can be retrofitted on non Xdrive N55s) and the S55 also uses a dual oil pump system.

BMW knows that the N55 suffers from oil starvations issues, and after speaking to an independent beemer tech who flew out to germany for some training of these motors, I have solid reason to believe that BMW didnt bother with upgrading the bearings because most of the time, if the bearings do fail due to: improper maintenance intervals, track abuse, neglect. They almost always fail outside of the manufacturer warranty.
IF i didnt have Xdrive, i would definetly forgo the VAC motorsport bearings and just get the S55 oil pan and oil pump retrofitted as it increases flow by "18%" which illiminates the oil starvation issue for all application; track/daily use and maybe even said 30 second donuts

Im not sure if the Xdrive oilpan is worse than the non Xdrive n55 oil pan. However I do know that we cannot swap the S55 oil pan due to said front drive shaft. Iv been trying to find out if we can swap the S55's dual oil pump and keep our stock oil pan. No luck tho on my research, no one has attempted it to my knowledge.

[lens]

Originally Posted by MadJonny

Xdrive oil sump is poorly designed due to the front driveshaft and maybe the oil was a little bit low. Shame to hear.

It should actually help, as it acts like a natural baffle, I track my xDrive every summer with no issues for the past 5 years, but you do have to check your oil level after every session and every now and then as you do burn oil. If the oil is low enough, oil will not be picked up.

[MadJonny]

Originally Posted by Jelly_Belly

Woah, sorry i havent posted in a while, been busy with the car.

Lots of replies, i really appreciate everyones inputs




Excellent point, I purchased the used M235i after extensive research because i figured id be better off having forged internals. However on the flip side, once my motor died. It was a huge pain in the ***.

In fact it was such a pain to find an M235i motor, that one of the local shops that services bimmers under warranty. Suggested I have my crankshaft machined and drop in with new bearings, as it would be easier than having to find a new motor. Another shop also suggested sourcing an N55 from a 335i and "just stage one it bro" (real response from a shop, i was shocked )
I respectfully denied both offers/solutions.

The motor i found with 15k miles on the clock ended up costing me 7.8k + shipping and i have to return my old core.

I just got the motor this week so its not in the car yet. im waiting on the VAC motorsport bearings to arrive.





So, it turns out that the N55 has a poor oil pan and oil pump design in the first place. this is why in the S55 of the m2, the oil pan was redesigned ( and can be retrofitted on non Xdrive N55s) and the S55 also uses a dual oil pump system.

BMW knows that the N55 suffers from oil starvations issues, and after speaking to an independent beemer tech who flew out to germany for some training of these motors, I have solid reason to believe that BMW didnt bother with upgrading the bearings because most of the time, if the bearings do fail due to: improper maintenance intervals, track abuse, neglect. They almost always fail outside of the manufacturer warranty.
IF i didnt have Xdrive, i would definetly forgo the VAC motorsport bearings and just get the S55 oil pan and oil pump retrofitted as it increases flow by "18%" which illiminates the oil starvation issue for all application; track/daily use and maybe even said 30 second donuts

Im not sure if the Xdrive oilpan is worse than the non Xdrive n55 oil pan. However I do know that we cannot swap the S55 oil pan due to said front drive shaft. Iv been trying to find out if we can swap the S55's dual oil pump and keep our stock oil pan. No luck tho on my research, no one has attempted it to my knowledge.

Hello,

No you cannot just add the second pump because it's not going to give any benefit. The second pump just gets the oil from the front of the the oil sump and sends it the rear enclosed area through the little sifon.
I don't even think that upgraded rods would solve any issue due to lack of oil. I don't remember but there is a product on the market that acts as a small oil sump in case of oil starvation but i cannot recall the name.

Also check out on youtube this lesson from HP garage maybe you can find some ideas for a custom solution for the Xdrive model
Budget Oiling Solution | Creating the Ultimate Wet Sump [GOLD WEBINAR LESSON]

Sorry for the bad pictures but they were just for personal use:

Left stock n55 sump, right S55 sump



Dual oil pump

[Jelly_Belly]

So, car is finally off the lift and on the road with the VAC motorsport bearings and the APR head studs. Drives like a dream.

Im still disappointed about the fact that our N55s suffer from the oil starvation problem and theres *seemed* to be no solution for those of us with Xdrive.

Well guess what! I believe to have found interesting for some of you.

MMR manufactures a baffle system for N55s which IS compatible with Xdrive.
It greatly improves on the oil starvation issue, while not as efficient as an S55 pan and pump. this is a great option for those of us who cant go down that route. Also cost wise its a much for accessible option. I will be linking the baffle here along with another thread of people discussing the effectiveness of the baffle.

Link to the baffle
https://www.turnermotorsport.com/p-4...ed-sump-plate/

Link to the other forum thread about said baffle
https://f30.bimmerpost.com/forums/sh....php?t=1833312

Im just annoyed that i discovered this AFTER my car came off the lift and the new engine is dropped in LOL

[123Britt]

What happens if (on track days) you just add 3/4 qt extra oil?

[XutvJet]

Originally Posted by 123Britt

What happens if (on track days) you just add 3/4 qt extra oil?

Overfilling by that much may make the oil frothy, thus potentially causing a lubrication issue.

These cars can handle track duty so as long as the oil level is correct and you're not on a track with a sustained high G turns. If you're running track tires, then the car could generate very high Gs, possibly sloshing the oil too far to one side of the pan for an extended time. You'd be best served to either:

1) Do the M2/3/4 S55 oil pump/baffle
2) Buy an M2

I don't see the point in doing the MMR baffle system over the S55 oil pump/baffle unless you have xdrive.

[Jelly_Belly]

^ This ^
Only reason someone would do the MMR baffle over the S55 parts if they had a RWD model is because its cost prohibitive. But if you cant afford the S55 parts you definetly have no business being at the track because a new motor will set you back 10k lol

[monster6a2]

Originally Posted by XutvJet

Rod bearing failures on the EWG N55s are rare. Like you said, when they fail in the EWG N55s, it's usually because of high lateral sustained Gs during track driving. The fix is the S55 oil sump parts swap.

With that said, with your mods, you are pushing the safeguard limits of the N55. One bad knock event could hammer the piston so hard that it squashes the oil film between the rod bearing and crank.

I strongly suggest never going moderate to heavy throttle in a tall gear (3rd and above) at rpms below 4000rpms. This is called a high load situation which can introduce a huge surge of boost and potentially low speed preignition (LSPI). In stock form, then DME is quick enough to respond to keep this from happening. With Stsge 2 and beyond mods, the DME might not be able to keep up.

While good practice,, changing oil often really isn't going to do much for preventing spun bearings.

Correct me if I’m wrong but to my knowledge, there are a select few N55 engines that superceed the build date of 09/12/2012 with the pwg, that have the new rod bearings. All of these cars are 2013 models but according to bmw, that’s the day they switched which rod bearings were used. Another thing as Ik this thread is old and this is now more well known, but anytime you disrupt the oil circulation, ex: changing the ofhg, you need to prime the engine. FCP Euro has multiple videos demonstrating how to do so.

[Kernel Kurtz]

Originally Posted by Jelly_Belly

Im still disappointed about the fact that our N55s suffer from the oil starvation problem and theres *seemed* to be no solution for those of us with Xdrive.

Well guess what! I believe to have found interesting for some of you.

MMR manufactures a baffle system for N55s which IS compatible with Xdrive.
It greatly improves on the oil starvation issue, while not as efficient as an S55 pan and pump. this is a great option for those of us who cant go down that route.

Replying to an old post, but this might be a good application for an accumulator (eg. Accusump) as well.