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      07-08-2021, 02:07 AM   #1
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N55 and oil starvation

How worried should I be about tracking my early N55 xdrive?
Is the oil starvation as much as an issue on the xdrive as in the non xdrive oil pans?
There doesn't seem to be a baffle for the xdrive and the early N55 have questionable rod bearings.

Heavy braking and right handers are the the worst for oi starvation, add R-comp tires and this could be a disaster.
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      07-15-2021, 12:30 PM   #2
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Thinking about this as well, and unfortunately xdrive too.

There is one guy on here who tracks his 335 and he just overfills the oil by about 1L and has been fine. As far as the rod bearings I believe I remember seeing another thread about them and the early 335s got the same bearing PN as the F80. Those shouldn't be an issue.

For eg. My build date shows 3/2013 so I believe my bearings are this part https://www.realoem.com/bmw/enUS/par...;q=11247628034

They superseded a PN that ends in 2012. The above link shows the new one is shared by the F8x m3 and m4
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      07-15-2021, 09:50 PM   #3
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Quote:
Originally Posted by Logicoeur View Post
For eg. My build date shows 3/2013 so I believe my bearings are this part https://www.realoem.com/bmw/enUS/par...&q=11247628034

They superseded a PN that ends in 2012. The above link shows the new one is shared by the F8x m3 and m4
Unfortunately my build date is August 2012... Considering that I need to get my oil pan gasket changed, I will make sure to get the rod bearing changed at the same time for piece of mind.

Do you think that the Xdrive oil pan is giving us an advantage regarding oil starvation?

If you google: Addressing N5x oiling and spun rod bearings (Accusump installed)
There is a very interesting thread, very long but lots of interesting information. Mainly E9X N55.
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      07-21-2021, 09:06 AM   #4
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Based on my reading, here's a solution
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      07-21-2021, 12:17 PM   #5
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Quote:
Originally Posted by lebaaron View Post
Based on my reading, here's a solution
I would be all over it if it worked for Xdrive. It is only for RWD like all the good camber modifying stuff.
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      07-21-2021, 01:56 PM   #6
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Quote:
Originally Posted by frchdragon View Post
I would be all over it if it worked for Xdrive. It is only for RWD like all the good camber modifying stuff.
Sorry about that 😕
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      08-02-2021, 11:11 PM   #7
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Has anyone with xdrive done anything that adds any peace of mind on the track?
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      08-27-2021, 03:44 PM   #8
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Quote:
Originally Posted by Logicoeur View Post

There is one guy on here who tracks his 335 and he just overfills the oil by about 1L and has been fine.
Sounds like a viable option until ponying up the 3k for the S55 Pump and Pan. I plan to do this until I rebuild the engine and go through the whole engine upgrade. Forged internals, etc.
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      08-27-2021, 04:44 PM   #9
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How do you know you are getting oil starvation with your 335? Are you receiving low oil pressure?
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      08-28-2021, 11:24 AM   #10
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It is a well documented issue on the N55 engine, the design of the oil pickup isn't optimal. they added a second pump on the S55 engine.
But the IX has a different oil pan, and I am wondering if it is better?
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      08-28-2021, 02:28 PM   #11
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Quote:
Originally Posted by frchdragon View Post
It is a well documented issue on the N55 engine, the design of the oil pickup isn't optimal. they added a second pump on the S55 engine.
But the IX has a different oil pan, and I am wondering if it is better?
I keep hearing about it for the N55 but very little in details. What exact error is being tossed? I don't doubt the S55 has better everything including oil pickup but BMW tested these 6 cylinders like the N55 335i on the Nurburgring.
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      08-31-2021, 04:44 PM   #12
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I'm not sure at what point this starvation happens as I do 4-5 hard track days and a number of autocross days every year and based on Blackstone tests at every oil change* there are no detectable wear concerns with my N55 in my 435xi. Im run some sort of 200tw tires and go for 20-30 minutes at a time for the track sessions, with 4-8 sessions per day. Current engine has ~40k miles and car is at ~87k miles. I change the oil every 4-5k miles (usually in the fall and late spring) and have done diffs, transfer case, and zf8 fluids at about 60k miles. I'm consistently using 5w-30 BMW oil.

I would say keeping an eye out on engine wear based on oil sample testing would be a good gage assuming things are in good shape when you start tracking the results. Not sure if one day can go from fine to blown engine though?

* Been obsessed and concerned with breaking current N55 engine as the first one spun a rod bearing at 47k miles, prior to all of my track driving and less than 15k miles I put on it since buying used. So, Blackstone gets a fair amount of oil from me My theory on the engine failure was a combination of long oil change intervals, possible hard driving when cold, and Camry cold starts by the previous owner and dealership. Guess it could have just been bad luck too.
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      09-01-2021, 12:37 AM   #13
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Oil starvation only happens during extremely excessive G force in left turns. It doesn't affect in other conditions.
From what I have read so far, short of M sump, nothing helps except extra oil in the sump.
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      09-02-2021, 10:51 PM   #14
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Quote:
Originally Posted by edycol View Post
Oil starvation only happens during extremely excessive G force in left turns. It doesn't affect in other conditions.
From what I have read so far, short of M sump, nothing helps except extra oil in the sump.
I agree with your statement. Accusump might be a solution or a partial one.
What a bad design.
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      09-03-2021, 04:06 AM   #15
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Quote:
Originally Posted by frchdragon View Post
Quote:
Originally Posted by edycol View Post
Oil starvation only happens during extremely excessive G force in left turns. It doesn't affect in other conditions.
From what I have read so far, short of M sump, nothing helps except extra oil in the sump.
I agree with your statement. Accusump might be a solution or a partial one.
What a bad design.
Well, it is inline six engine. They come with some drawbacks.
They already have bigger capacity than comparable or even larger V6. Problem going bigger sump in this case would be time to warm up oil=mpg and emissions. If going M design in regular vehicles issue is around cost and probably xDrive.
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      09-03-2021, 12:05 PM   #16
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Quote:
Originally Posted by rphz View Post
I'm not sure at what point this starvation happens as I do 4-5 hard track days and a number of autocross days every year and based on Blackstone tests at every oil change* there are no detectable wear concerns with my N55 in my 435xi. Im run some sort of 200tw tires and go for 20-30 minutes at a time for the track sessions, with 4-8 sessions per day. Current engine has ~40k miles and car is at ~87k miles. I change the oil every 4-5k miles (usually in the fall and late spring) and have done diffs, transfer case, and zf8 fluids at about 60k miles. I'm consistently using 5w-30 BMW oil.

I would say keeping an eye out on engine wear based on oil sample testing would be a good gage assuming things are in good shape when you start tracking the results. Not sure if one day can go from fine to blown engine though?

* Been obsessed and concerned with breaking current N55 engine as the first one spun a rod bearing at 47k miles, prior to all of my track driving and less than 15k miles I put on it since buying used. So, Blackstone gets a fair amount of oil from me My theory on the engine failure was a combination of long oil change intervals, possible hard driving when cold, and Camry cold starts by the previous owner and dealership. Guess it could have just been bad luck too.
You would be the perfect test case with an N55 EWG in an XDrive and regular track days. Anecdotal evidence seems to indicate that the XDrive oilpan shape is like a natural baffle guarding against oil starvation at the oil pickup.

You are obviously doing everything right with maintenance and Blackstone oil analysis. See if you can log the oil pressure reading as you are tracking. That should tell you if you are anywhere near to having a problem, or not at all. Please post any data/conclusions that you obtain. There would be great interest in actual data since it's mostly been speculation
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      09-04-2021, 10:06 PM   #17
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Quote:
Originally Posted by johnung View Post
Quote:
Originally Posted by rphz View Post
I'm not sure at what point this starvation happens as I do 4-5 hard track days and a number of autocross days every year and based on Blackstone tests at every oil change* there are no detectable wear concerns with my N55 in my 435xi. Im run some sort of 200tw tires and go for 20-30 minutes at a time for the track sessions, with 4-8 sessions per day. Current engine has ~40k miles and car is at ~87k miles. I change the oil every 4-5k miles (usually in the fall and late spring) and have done diffs, transfer case, and zf8 fluids at about 60k miles. I'm consistently using 5w-30 BMW oil.

I would say keeping an eye out on engine wear based on oil sample testing would be a good gage assuming things are in good shape when you start tracking the results. Not sure if one day can go from fine to blown engine though?

* Been obsessed and concerned with breaking current N55 engine as the first one spun a rod bearing at 47k miles, prior to all of my track driving and less than 15k miles I put on it since buying used. So, Blackstone gets a fair amount of oil from me My theory on the engine failure was a combination of long oil change intervals, possible hard driving when cold, and Camry cold starts by the previous owner and dealership. Guess it could have just been bad luck too.
You would be the perfect test case with an N55 EWG in an XDrive and regular track days. Anecdotal evidence seems to indicate that the XDrive oilpan shape is like a natural baffle guarding against oil starvation at the oil pickup.

You are obviously doing everything right with maintenance and Blackstone oil analysis. See if you can log the oil pressure reading as you are tracking. That should tell you if you are anywhere near to having a problem, or not at all. Please post any data/conclusions that you obtain. There would be great interest in actual data since it's mostly been speculation
Oil pressure cannot be logged. Pressure sensor/switch on OFH is dummy one. One would have to install specific sensor to fallow actual values.
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      10-13-2021, 09:10 PM   #18
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Quote:
Originally Posted by johnung View Post
You would be the perfect test case with an N55 EWG in an XDrive and regular track days. Anecdotal evidence seems to indicate that the XDrive oilpan shape is like a natural baffle guarding against oil starvation at the oil pickup.

You are obviously doing everything right with maintenance and Blackstone oil analysis. See if you can log the oil pressure reading as you are tracking. That should tell you if you are anywhere near to having a problem, or not at all. Please post any data/conclusions that you obtain. There would be great interest in actual data since it's mostly been speculation
So I finally had a chance to get back out on the track for an open lapping day last weekend and logged a lap that ended up being very helpful for several reasons (more to come on that). Oil pressure appears to be good, and drops into the 20's when there's no throttle input, which is primarily into corners and prior to apexes. I'm interested in any feedback from anyone about what they see up until the very end of this log*.

Here's the log: https://datazap.me/u/rphz/log-163374...ta=13-15-19-20

This is from MHD, car is running stage 1 on this lap (and more or less FBO). The track is High Plains Raceway in the full course arrangement, and t=255-ish is the apex of corner 3 coming into the long straight. t=383-ish is that same point in corner 3 a lap later. Ambient temp was about 75 degrees (F). This lap was at about 90% of maximum as my car shutdown in the previous session for unknown reasons. Outside of the issues I had at the end of the lap in this log, everything looks pretty good to me until t=389 when my car shutdown again.

I just did an oil change after this sessoin and will be sending this to Blackstone so will post back once I get the results. For the first time ever with this car, I ended the day with a warning about being 1 quart low in oil literally as I got on the highway leaving the track for the day. I've been driving the car hard this year in both stage 1 and 2 on and off the track, have overheated several times with oil at 277 F and water at 250 F so hoping this will help explain the extra consumption as I'm not leaking oil anywhere.

*Not to derail the topic much, but my car shutdown due to a complete loss of fuel pressure at the t=389 mark from the above log (just starting down the straight). I think my fuel pump module is starting to fail and overheat as this was the second time after about 10 minutes into the session that it happened. Codes indicate both pumps had no pressure, and the MHD log thankfully shows rail pressure drop to 0 immediately. I ended up pulling off track and restarting to limp back to the paddock. Car has been fine on the street since this happened. What a great way to end the season!

Any questions or feedback regarding the log data and oil pressure would be greatly appreciated!
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      10-14-2021, 06:01 AM   #19
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Quote:
Originally Posted by rphz View Post
Quote:
Originally Posted by johnung View Post
You would be the perfect test case with an N55 EWG in an XDrive and regular track days. Anecdotal evidence seems to indicate that the XDrive oilpan shape is like a natural baffle guarding against oil starvation at the oil pickup.

You are obviously doing everything right with maintenance and Blackstone oil analysis. See if you can log the oil pressure reading as you are tracking. That should tell you if you are anywhere near to having a problem, or not at all. Please post any data/conclusions that you obtain. There would be great interest in actual data since it's mostly been speculation
So I finally had a chance to get back out on the track for an open lapping day last weekend and logged a lap that ended up being very helpful for several reasons (more to come on that). Oil pressure appears to be good, and drops into the 20's when there's no throttle input, which is primarily into corners and prior to apexes. I'm interested in any feedback from anyone about what they see up until the very end of this log*.

Here's the log: https://datazap.me/u/rphz/log-1633745569?log=0&data=13-15-19-20

This is from MHD, car is running stage 1 on this lap (and more or less FBO). The track is High Plains Raceway in the full course arrangement, and t=255-ish is the apex of corner 3 coming into the long straight. t=383-ish is that same point in corner 3 a lap later. Ambient temp was about 75 degrees (F). This lap was at about 90% of maximum as my car shutdown in the previous session for unknown reasons. Outside of the issues I had at the end of the lap in this log, everything looks pretty good to me until t=389 when my car shutdown again.

I just did an oil change after this sessoin and will be sending this to Blackstone so will post back once I get the results. For the first time ever with this car, I ended the day with a warning about being 1 quart low in oil literally as I got on the highway leaving the track for the day. I've been driving the car hard this year in both stage 1 and 2 on and off the track, have overheated several times with oil at 277 F and water at 250 F so hoping this will help explain the extra consumption as I'm not leaking oil anywhere.

*Not to derail the topic much, but my car shutdown due to a complete loss of fuel pressure at the t=389 mark from the above log (just starting down the straight). I think my fuel pump module is starting to fail and overheat as this was the second time after about 10 minutes into the session that it happened. Codes indicate both pumps had no pressure, and the MHD log thankfully shows rail pressure drop to 0 immediately. I ended up pulling off track and restarting to limp back to the paddock. Car has been fine on the street since this happened. What a great way to end the season!

Any questions or feedback regarding the log data and oil pressure would be greatly appreciated!
Great stuff! Thanks for posting. Only had time for a quick read right now. Oil temperature jumped out at me. Had a conversation a few years ago with a racing oil cooler designer who told me that N55 was good to an oil temperature of 260F but above that consider an oil cooler upgrade.

This Evolution Racewerks oil cooler upgrade is the one that I chose after researching but never got it. I was impressed with the quality of the stainless lines and the development of the shroud. Many aftermarket products are slapped together but this one was obviously well thought out and tested under race conditions.

http://www.evolutionracewerks.com/node/299

Evolution Racewerks also has this insane two oil cooler racing setup.

http://www.evolutionracewerks.com/node/133

Evolution Racewerks is a US based company that manufactures here so their quality and quality control is excellent.

Since then Mishimoto has come out with some nice products so they may have an oil cooler upgrade worth considering as well.

Since then I have installed this Mosselman oil thermostat. I had been skeptical but after using it, I was very surprised how well it works. I used to be able to get my N55 EWG on a hot day with hard street driving to hit as high as 265F. But with the Mosselman during this hot summer I never got over 250F. My conservative estimate is that my oil temperatures are 15-35 degrees Fahrenheit less than stock.

https://www.kiesmotorsports.com/prod...1046613?aff=22

Mosselman Installation video
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      07-28-2022, 10:08 AM   #20
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Hey guys really sorry for the thread bump however im in a bit of a conumdrum.

The N55 in my M235I recently spun a rod bearing, im in the process of swapping out the engine and im looking to make sure this never happens again. I was considering installing the S55 pan and pump however this thread has made me aware that the S55 pan may not be compatible with my M235I due to Xdrive.

Do we know if the S55 oil pump is also incompatible with our Xdrive N55 EWG?

I have found an interesting option for you guys also to avoid spun rod bearings. VAC Motorsports sells upgraded bearings which can take more of a beating and are designed for track use.

https://store.vacmotorsports.com/vac...s55-p2723.aspx

Its been almost a year since you guys last posted on this thread. would appreciate an update from some of you who have had another season of tracking to give me some input on your experiences.

As you guys said, we are such a minority among N55 owners that anecdotal experience seems to be the best source of info.
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      07-28-2022, 11:22 AM   #21
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Quote:
Originally Posted by Jelly_Belly View Post
Hey guys really sorry for the thread bump however im in a bit of a conumdrum.

The N55 in my M235I recently spun a rod bearing, im in the process of swapping out the engine and im looking to make sure this never happens again. I was considering installing the S55 pan and pump however this thread has made me aware that the S55 pan may not be compatible with my M235I due to Xdrive.

Do we know if the S55 oil pump is also incompatible with our Xdrive N55 EWG?

I have found an interesting option for you guys also to avoid spun rod bearings. VAC Motorsports sells upgraded bearings which can take more of a beating and are designed for track use.

https://store.vacmotorsports.com/vac...s55-p2723.aspx

Its been almost a year since you guys last posted on this thread. would appreciate an update from some of you who have had another season of tracking to give me some input on your experiences.

As you guys said, we are such a minority among N55 owners that anecdotal experience seems to be the best source of info.
The oilpans, pickups, etc are completely different and completely incompatible between the two. I mean the damn driveshaft goes right through the middle of the XDrive pan.
Don't even ask if something oilpan related from a RWD car will fit an XDrive car, or vice versa. It will not!

VAC coated bearings have an excellent reputation for doing what you said. If I ever replace my bearings those are the bearings that I will use. Any negatives that I read boil down to a complaint that the price is too high, or someone who has some vague personal beef with VAC. I have some VAC parts on my car. They make high quality stuff.

Sorry to hear about your engine below are links to two parts that are on my car for extra insurance/protection that you may want to consider. There are some similar products on the market that are junk compared to these from Kies Motorsports.

KIES SEAL GUARD
https://www.kiesmotorsports.com/prod...8;_ss=r?aff=22

Note: Make sure that when they install your new front crankshaft seal that they use the newest 10mm deep seal and that they recess it's at least 5mm into its cylinder. That's how BMW has been installing them from the factory for many years since the F3x began. But they may have not updated the installation instructions so it appears like the seal is to be installed flush like they did with the N54 and early N55 engines that used the 20mm deep front crankshaft seal. See photo.

KIES SEAL GUARD INSTALLATION


KIES BOLT LOCK
https://www.kiesmotorsports.com/prod...8;_ss=r?aff=22

Hope this helps!
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      09-07-2022, 07:57 AM   #22
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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.
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