[indyjoeshmo]

Originally Posted by carguy138

Early N55 here. Recently spun rod bearings at 72k with an accusump installed.

Did everything right (2nd owner, 3 track days in 8 years, 4-5k OCI, garaged in winter, always warmed up/cooled down, etc.) and it still happened to me. These motors have zero baffling in the oil pan and who knows how robust the plastic oil sump pickup is over time.

Aside from the common OFHG replacement priming sequence and the serpentine belt slipping off a pulley and getting sucked in the front crankshaft seal, here are a couple..

In chasing fuel economy, BMW speced tiny rod bearings (compared to other similar sized motors) which combined with tight rod bearing clearances and only one anti rotation tab, lends to spinning after many expansion/contraction cycles of the rod bearings and crank lobes.

Another theory is that over time the torque to yield rod bolts lose their tension and create excess clearance which is indicative of 12 and 6 o'clock wear on the bearing shells.

There is something funky going on with the bottom end of these motors and I doubt we'll ever find out unless a BMW engineer spills the beans.

I wouldn't push these motors too hard on the track. In the event a motor goes, expect to spend $5-8k for a used or rebuilt motor or $15k for a new BMW longblock. Labor depending on the shop can easily be in the $5k range.

Then you run into the "let's replace XYZ while the motor is out" like motor mounts, clutch, flywheel, starter, oil/coolant lines, vac lines, etc. It adds up quickly.

Sorry to hear about another engine loss. What tires were you running? Were you running a tune as well?

[carguy138]

Originally Posted by indyjoeshmo

Sorry to hear about another engine loss. What tires were you running? Were you running a tune as well?

Brand new set of Continental Extreme Contact Force (200TW). Before that Michelin Pilot Super Sports. MHD 2+ 91ACN tune but with 93 octane fuel (for extra octane margin) for several years.

On the day it happened, the first 15 minute run session went fine. In the second session, I pulled off after 10 minutes to grab some water and it stalled while pulling into the garage bay. Seized up. After 20 minutes I was able to get it to start but had rod knock.

For some context this was my first track day of the year on a cool spring day. Wasn't hard on the car at all and oil temps never went above 245-250 degrees. Burned zero oil and gave zero warning signs.

[Jelly_Belly]

Originally Posted by carguy138

Early N55 here. Recently spun rod bearings at 72k with an accusump installed.

Did everything right (2nd owner, 3 track days in 8 years, 4-5k OCI, garaged in winter, always warmed up/cooled down, etc.) and it still happened to me. These motors have zero baffling in the oil pan and who knows how robust the plastic oil sump pickup is over time.

Aside from the common OFHG replacement priming sequence and the serpentine belt slipping off a pulley and getting sucked in the front crankshaft seal, here are a couple..

In chasing fuel economy, BMW speced tiny rod bearings (compared to other similar sized motors) which combined with tight rod bearing clearances and only one anti rotation tab, lends to spinning after many expansion/contraction cycles of the rod bearings and crank lobes.

Another theory is that over time the torque to yield rod bolts lose their tension and create excess clearance which is indicative of 12 and 6 o'clock wear on the bearing shells.

There is something funky going on with the bottom end of these motors and I doubt we'll ever find out unless a BMW engineer spills the beans.

I wouldn't push these motors too hard on the track. In the event a motor goes, expect to spend $5-8k for a used or rebuilt motor or $15k for a new BMW longblock. Labor depending on the shop can easily be in the $5k range.

Then you run into the "let's replace XYZ while the motor is out" like motor mounts, clutch, flywheel, starter, oil/coolant lines, vac lines, etc. It adds up quickly.

Dude thats nuts. Absolutely nuts. Cant believe you babied the car and still stun a bearing.

Btw now that my swap is complete i can give you guys a final number.

10k CAD for a used N55 from an M235I, 1.5k CAD for APR head studs and VAC motorsport bearings. and then you ad in Labour... Canada has crazy taxes so il spare you the final bill lol. But yea. i think 10 USD for engine and labour is an acceptable quote BEFORE you throw in any add-ons.


Carguy, because you go ahead the with swap. I have a question, do you plan on addressing the oil starvation issue? either with an MMR baffle or S55 pumps and pan?

[carguy138]

Originally Posted by Jelly_Belly

Dude thats nuts. Absolutely nuts. Cant believe you babied the car and still stun a bearing.

Btw now that my swap is complete i can give you guys a final number.

10k CAD for a used N55 from an M235I, 1.5k CAD for APR head studs and VAC motorsport bearings. and then you ad in Labour... Canada has crazy taxes so il spare you the final bill lol. But yea. i think 10 USD for engine and labour is an acceptable quote BEFORE you throw in any add-ons.


Carguy, because you go ahead the with swap. I have a question, do you plan on addressing the oil starvation issue? either with an MMR baffle or S55 pumps and pan?

Funny you should mention that because I've been heavily researching this. From what I've gathered, there isn't a good option for the E series N55 motors, especially with X-drive (which I have). S55 oil pump retrofits won't work because of the E-series power steering rack.

My option at this point would be to remove the front differential, separate front axles to only retain the outer hubs, remove center driveshaft, run x-delete (which I have) and install a RWD N55 oil pan. From there I could install a VAC oil pan baffle.

I have 700 miles on the rear Wavetrac LSD from diffsonline and haven't used the AWD in several years due to x-delete. I just need to decide if I want to commit to this route because it's fairly difficult to return to "stockish" if I decide to sell it in the future.

The whole ordeal is frustrating to say the least but I'm over it and now looking for the best path forward so I can enjoy the car again!

[Jelly_Belly]

Originally Posted by carguy138

Funny you should mention that because I've been heavily researching this. From what I've gathered, there isn't a good option for the E series N55 motors, especially with X-drive (which I have). S55 oil pump retrofits won't work because of the E-series power steering rack.

My option at this point would be to remove the front differential, separate front axles to only retain the outer hubs, remove center driveshaft, run x-delete (which I have) and install a RWD N55 oil pan. From there I could install a VAC oil pan baffle.

I have 700 miles on the rear Wavetrac LSD from diffsonline and haven't used the AWD in several years due to x-delete. I just need to decide if I want to commit to this route because it's fairly difficult to return to "stockish" if I decide to sell it in the future.

The whole ordeal is frustrating to say the least but I'm over it and now looking for the best path forward so I can enjoy the car again!

Oh man, ok thats rough, so the MMR baffle isnt compatible with your E chassis N55. And the VAC Motorsports one isnt compatible because of X drive.... Dude, you sir are stuck between a rock and a hard place..

Um. Yea no one's gonna have the right answer for your case. But do keep in mind. You assume you are gonna sell the car eventually. I will say that I modded my other car (A mk6 Golf) so extensively that by the time i was gonna sell it, it made no sense for me to put up an asking price that I thought matched the work that was done on the car. ( I wasnt asking a crazy amount, just higher than what other models with lower mileage were asking)

You never get back the money you put into your car in mods. You just dont. So i guess you need to ask yourself if you really wanna sell the car eventually and if the answer is yes, is it worth putting in all that work? Or do you do the work and keep the car forever.

[arekuf3x]

Originally Posted by carguy138

Early N55 here. Recently spun rod bearings at 72k with an accusump installed.

Did everything right (2nd owner, 3 track days in 8 years, 4-5k OCI, garaged in winter, always warmed up/cooled down, etc.) and it still happened to me. These motors have zero baffling in the oil pan and who knows how robust the plastic oil sump pickup is over time.

Aside from the common OFHG replacement priming sequence and the serpentine belt slipping off a pulley and getting sucked in the front crankshaft seal, here are a couple..

In chasing fuel economy, BMW speced tiny rod bearings (compared to other similar sized motors) which combined with tight rod bearing clearances and only one anti rotation tab, lends to spinning after many expansion/contraction cycles of the rod bearings and crank lobes.

Another theory is that over time the torque to yield rod bolts lose their tension and create excess clearance which is indicative of 12 and 6 o'clock wear on the bearing shells.

There is something funky going on with the bottom end of these motors and I doubt we'll ever find out unless a BMW engineer spills the beans.

I wouldn't push these motors too hard on the track. In the event a motor goes, expect to spend $5-8k for a used or rebuilt motor or $15k for a new BMW longblock. Labor depending on the shop can easily be in the $5k range.

Then you run into the "let's replace XYZ while the motor is out" like motor mounts, clutch, flywheel, starter, oil/coolant lines, vac lines, etc. It adds up quickly.

S55 doesnt have rod bearings issues and ewg n55 uses the same rod bearings. It’s definitely oil starvation issue, early n55s had weaker rod bearings. M235i R race car uses n55 with s55 oil sump, that’s the best solution. I wouldn’t even track e9x n55/54, unless it had at least MMR baffle installed.

[zinner]

Anything on the track is going to have issues, it's the nature of the beast. People will replace the road bearings as maintenance, teams rebuild entire engines after X races. I see almost one exploded engine a weekend at the track and those are just the ones I run across. Latest was a FA20 on a BRZ, blew a rod through the top of the block. Nice of them not to spill a drop of oil on the track!

I replaced my rod bears after I had metal in the oil. Aug 2014 N55 EWG F30

[Ki330i]

Have a 2015 f31 335i and recently changed the oil . Car is on 70k with full bmw service history. Was a 1 owner car by an old guy into his car that traded the f31 for a yaris GR. No weird noises from the car but thought I'd check curiosity and cut apart the oil filter and discovered a lot of very large chunks of metal . Took apart the bottom end thinking I've spun the notorious rod bearings but they were fine and in surprisingly good condition. Car is stage 2+ mhd tuned and always warmed up and cooled down properly . The car does get the occasional spirited weekend drives but nothing like that of track days with minutes off full throttle. Took off the valve cover to check if the vvt cam had worn away but noticed the back 2 lobes of the intake cam are absolutely mullered and look to have been starved of oil as the very back of the cam has began to develop some surface corrosion , this has also wiped both lifters out . Is this a common thing as I can't find any information on this ? Will be rebuilding with ACL Race bearings and Arp2000 rod bolts

[F32Fleet]

Originally Posted by Ki330i

Have a 2015 f31 335i and recently changed the oil . Car is on 70k with full bmw service history. Was a 1 owner car by an old guy into his car that traded the f31 for a yaris GR. No weird noises from the car but thought I'd check curiosity and cut apart the oil filter and discovered a lot of very large chunks of metal . Took apart the bottom end thinking I've spun the notorious rod bearings but they were fine and in surprisingly good condition. Car is stage 2+ mhd tuned and always warmed up and cooled down properly . The car does get the occasional spirited weekend drives but nothing like that of track days with minutes off full throttle. Took off the valve cover to check if the vvt cam had worn away but noticed the back 2 lobes of the intake cam are absolutely mullered and look to have been starved of oil as the very back of the cam has began to develop some surface corrosion , this has also wiped both lifters out . Is this a common thing as I can't find any information on this ? Will be rebuilding with ACL Race bearings and Arp2000 rod bolts

First I've read about the intake cams.

[TrackEnthusiast]

As a 2014 M135i owner that hve the car mostly for the track days, I also was very concerned about this oil starvation issue. I already sourced the parts for an oil pan/pump upgrade, however, before putting a good amount of bucks into it, I first decided to log the oil pressures on the track to see, for the tires I use and for my driving, how bad this starvation would or wouldn't be.

Nowaday, with MHD, it is very easy to make a good log and yes, at least for my particular model, it does log the oil pressure, I believe directly from the OEM sensor, which lives near the oil filter housing. Along with my GoPro, that has GPS, I managed to put together a video of a couple of very hot laps in a very hot day (35°C).

To put in context the numbers of the video below, a brief description of the cars setup:
- Tune: MHD stage 0 map w/ Catless 3" DP and OEM IC
- Fuel: 98RON E25 (Brazilian premium gas)
- Wheels/Tires: Chinese 18"x8,5"xET35 with KUMHO ECSTA PS71 245/40r18 all around
- Suspension: F80 LCA/TCA

So, as you can see in the video, pressure never drops below 3 bar, and the most critical pressure drop happens when turning left and braking. Anyways, by looking at the charts in MMR website:

https://mmrshop.co.uk/products/bmw-n55-oil-sump-baffle

My understanding is that my engine should be OK, and that corroborates what I got somewhere in this forum, where it was stated that "as long as you are on street tires the OEM sump and oil pump should be enough).

If anyone thinks differently, please let me know, as I still have access to the S55 parts, and I'll buy them as long as they are REALLY necessary to keep my engine alive. For now, by looking at the other data in the video, my conclusion is that, despite the catless DP and the MHD tune with lower coolant targets, engine still runs too hot. IAT goes almost to 80°C at some points, and then the most imediate upgrade is a bigger IC, which I already ordered. If that doeswn't do the trick, then I'll choose between secondary oil cooler or bigger radiator.

[Polo08816]

Originally Posted by TrackEnthusiast

As a 2014 M135i owner that hve the car mostly for the track days, I also was very concerned about this oil starvation issue. I already sourced the parts for an oil pan/pump upgrade, however, before putting a good amount of bucks into it, I first decided to log the oil pressures on the track to see, for the tires I use and for my driving, how bad this starvation would or wouldn't be.

Nowaday, with MHD, it is very easy to make a good log and yes, at least for my particular model, it does log the oil pressure, I believe directly from the OEM sensor, which lives near the oil filter housing. Along with my GoPro, that has GPS, I managed to put together a video of a couple of very hot laps in a very hot day (35°C).

To put in context the numbers of the video below, a brief description of the cars setup:
- Tune: MHD stage 0 map w/ Catless 3" DP and OEM IC
- Fuel: 98RON E25 (Brazilian premium gas)
- Wheels/Tires: Chinese 18"x8,5"xET35 with KUMHO ECSTA PS71 245/40r18 all around
- Suspension: F80 LCA/TCA

So, as you can see in the video, pressure never drops below 3 bar, and the most critical pressure drop happens when turning left and braking. Anyways, by looking at the charts in MMR website:

https://mmrshop.co.uk/products/bmw-n55-oil-sump-baffle

My understanding is that my engine should be OK, and that corroborates what I got somewhere in this forum, where it was stated that "as long as you are on street tires the OEM sump and oil pump should be enough).

If anyone thinks differently, please let me know, as I still have access to the S55 parts, and I'll buy them as long as they are REALLY necessary to keep my engine alive. For now, by looking at the other data in the video, my conclusion is that, despite the catless DP and the MHD tune with lower coolant targets, engine still runs too hot. IAT goes almost to 80°C at some points, and then the most imediate upgrade is a bigger IC, which I already ordered. If that doeswn't do the trick, then I'll choose between secondary oil cooler or bigger radiator.

That's good info.

When my N55 died at the track, it had almost 150,000 miles on it. Hard to tell if it's just due to age or oil starvation, but I do have the pumps for the S55 oil sump ready to go for next track season.

[E90lova]

Originally Posted by Polo08816

That's good info.

When my N55 died at the track, it had almost 150,000 miles on it. Hard to tell if it's just due to age or oil starvation, but I do have the pumps for the S55 oil sump ready to go for next track season.

Did you get your Rod bearings done before that failure?

[Polo08816]

Originally Posted by E90lova

Did you get your Rod bearings done before that failure?

No I did not.

But I don't think the root cause was a rod bearing failure. It was more likely the oil pump failure. When I went back through the data logs for oil temps, it rose quickly for 1-2 minutes before the engine completely failed.

[DailyDriveSebasite]

I found this forum when i was searching about oil sarvation on N55.

I have M135i Xdrive 2013 (so probably was build in 2012) i'm owner 4month. Car is almost 100% original and at the moment have just charge pipe replace with FTP alloy after 2 plastic one broke. One was original which broke next day after purchase car so i was little upset but however it is like it is.

i wanna use car daily because i have for my company and also for driving from customer to customer, but also to go sometimes on track day. I wanna keep car mostly from outside original and not hard racing. However i will do all safe things to keep car in best shape. I found that oil pan have a small leaq and i is not easy job to do because need to all subframe remove and also engine holders and and. So i will do this probably in February and i will change oil sump seal and rod bearings for kings racing bearings (i have good experiance with them because i build many R53 mini cooper engines and was best option) and because car have 158k km i will put original measurment and also ARP bolts inside. There i wanna be safe for go on trackday (i wanna go on nurburing turistdrive) so i will put also MMR and i think that i'm safe than. Of course is some $$$ investment on parts but luckily i do all work alone. There i wanna put also lower oil thermostat in the same work, so i believe is first stem and lower part of engine ready and should be no problem. I plan to change oil one time on year doesn't matter on KM what i do (normaly i do around 6-7000km) or after third Nurburing day, because is low cost and can not be bad for engine.