N55 - Rod Bearing Failure & Oil Starvation?

[BruceThomas]

Hi Guys,

Looking for any advise, guidance or anybody who has been through a similar situation.

2011 135 N55
6 MT
65K Miles
FBO
Pure Stage 2 Turbo - only installed for 600 miles
Wedge Tuning Custom Map - 91 ACN
Extensive Suspension/Handling Upgrades

I have owned the car for less than 5K miles and had the PS2 installed and all suspension/handling mods.

The car had been running stock spark plugs, but had no miss fires etc. Now replaced with NGK 97506 at .022"

Car is used only for (very) hard canyon driving.

Have been putting in 1.5 gallon of E85 per tank to help with timing corrections.

Worked with Wedge over multiple revisions to get a reliable map, suited to canyon driving, producing estimated 390ish WHP.

As of yesterday, I had the oil changed and there is considerable metal flake build up on the magnetic oil plug. See picture. No metal in the oil filter.

Oil had been previously changed when the PS2 was installed roughly 600 mile ago. I replaced the oil, as after the last drive, I got a low oil warning light.

All advise and suggestion so far has indicated the beginning of a rod bearing failure. No noises, no lights, no physical indication......yet.

With the investment I have in to the car to date, I am OK doing the rod bearings but have some questions:

1) Is there going to be any additional damage to the engine, other than the rod bearings? So are we fixing one area, for there to now be other compromised areas?

2) If I fix the rod bearings, will this just happen again? It seems a very quick demise that occurred in this instance, as the oil was changed less than 600 miles ago and no note of metal flakes then.

3) Is this an oil starvation issue from hard canyon driving? Lots of turns and lots of bumps contributing to oil bouncing everywhere? Are there any viable/proven solutions? Baffle pans? AccuSumps? Over fill?

Many thanks to everyone in advance.

The car is parked up and not moving, I would like to get the rod bearings replaced if this is sensible, but also understand the future of the motor.

Cheers,

Bruce

[Jhonea02]

So I have read a lot of reviews and posts about he n55 oil starvation because I am paranoid that itll happen to mine. A lot of the info i have read is that oil pressure drops on high g lefts. and that a baffle doesnt really help, ive seen sheets and oil pressure still drops like crazy even with a baffle. But the accusump I have heard good and bad, the good is the oil pressure doesnt drop like it does without the accusump, but it still drops some which obviously is not what you want while youre driving hard.

So onto your questions

1) If the bearing hasnt spun around the crankshaft, there shouldnt be any other damage i wouldnt think. Just wear to the bearing because its made out of softer material meaning it will wear and not the crankshaft.

2) If you fix the rod bearings and dont do anything about the dropping oil pressure then sure it will happen again because they arent getting the proper oil. One thing you could do is get an oil analysis to see if it is rod bearing material

3) it could be oil starvation but i really dont know for sure, especially if youre driving it hard and only hard. And im sure you know this but to not drive the car super hard on oil thats not up to temp.

[BruceThomas]

Hi Jhonea02,

Thanks for the reply.

I have always been aware of rod bearing issues with other BMW models, but was told that the 135 and N55 did not suffer from it.......

Infact, I just spoke to a well known tuner who flat out said, they have never seen an N55 blow, even running big power.

This suggests, that most tuned/big power guys are keeping the cars flat and level for drag and freeway pulls.

Starting to see a pattern between guys that canyon/track the cars vs. those who keep them level, which indicates that this is all linked to oil starvation/pick up.

Without any known for sure solution to keeping oil pick up and pressure consistent , it all seems a bit of a pointless task?

Maybe someone else can add their experience with solutions?

Thanks for the reply.

Bruce

[Jhonea02]

Originally Posted by BruceThomas

Hi Jhonea02,

Thanks for the reply.

I have always been aware of rod bearing issues with other BMW models, but was told that the 135 and N55 did not suffer from it.......

Infact, I just spoke to a well known tuner who flat out said, they have never seen an N55 blow, even running big power.

This suggests, that most tuned/big power guys are keeping the cars flat and level for drag and freeway pulls.

Starting to see a pattern between guys that canyon/track the cars vs. those who keep them level, which indicates that this is all linked to oil starvation/pick up.

Without any known for sure solution to keeping oil pick up and pressure consistent , it all seems a bit of a pointless task?

Maybe someone else can add their experience with solutions?

Thanks for the reply.

Bruce

https://www.1addicts.com/forums/show....php?t=1752666

Read this.

Also look up n55 accusump install and read some stuff about a guy whos motor let go

[amg6975]

There are a lot of us that have had N55s let go during track use. I personally know a couple people that aren't on the forums that had it happen as well. I do not think it's a big secret at this point that they have starvation issues.

[fatty335]

Originally Posted by BruceThomas

As of yesterday, I had the oil changed and there is considerable metal flake build up on the magnetic oil plug. See picture. No metal in the oil filter.

OP,

Regarding your initial discovery, I'm not aware of any BMW rod bearing formulation that utilizes a babbitt (top) layer that would stick to a magnet (older style lead/copper or newer style tin/aluminum). The only portion of a rod bearing that would stick like that is the steel backing and, had you worn one to the point your crank was grinding up the steel backing, I would assume you'd have several other, very noticeable symptoms. All that to say your discovery doesn't immediately make me think rod bearings.

[BruceThomas]

Hey Guys,

Thanks for all the replies.

A brief update on my side.

The pan was dropped and the rod bearings taken out. The shop states that there is some scouring on them but the images do not look terrible? The crank was reported to be good. Images of the bearings attached.

So - new King rod bearings went in and for good measure 'while we are there' we put the VAC baffle pan in. This has mixed reviews/effectiveness.

Going to use Motul 300V 5W40 100% Synthetic Road Racing Engine Oil as the car is pushed hard and the tuner advised this was the best option to use.

So all in all, I'm not sure the rod bearings are the culprit, as @fatty335 stated. Could be a bunch of work for something else to go pop.

Will do a 500 mile bed in for the new bearings, change the oil again and then back to it.

Thanks

[Petro135]

I spun a bearing it was an n54 not 55 but there was nothing on my magnetic plug. There was glitter in my oil filter. And there was large flakes in my oil pickup tube screen and in bottom of my oil pan. With that said I've seen several people with n55 that spun bearings after turbo upgrade. So you changing them was just good maintenance and might have saved your crank in the future. But if I were you I'd do a few quick interval oil changes to flush your motor out and check filter really well to get whatever metal out of your motor that is in there. And if you have an oil cooler change it. It's very hard to flush metal flake out of those. Ask me how I know

[BruceThomas]

Hey Guys,

Well an update is due. And it is not great news....

Rod bearings were replaced. The car was driven the 500 miles to break them in.

Had the oil replaced again at 500 miles and....... lots of metal flakes on the magnetic oil plug, including a a very thin slither that was about 25mm long.

Oil filter was full of flakes in every compartment and the oil looked like the nights sky with stars in it.

So - prognosis is not good.

Car continues to drive 100%. Seeing as the outlook looks bleak, I did a 3rd gear log just to see how things went and it produced very solid numbers with minor timing corrections on 91 ACN.

No codes. No hesitation. No indication of any issues.

Shop advised to run the car for another 500 miles and check the oil again, but this just seems futile at this point? So its a ticking time bomb....

Anybody have any ideas? What could this be? Certainly seems to be an issue, post the PS2 install.

Cheers

[fatty335]

https://www.e90post.com/forums/showthread.php?t=1582205

BT,

The link above looks like a similar situation to yours: higher mileage N55, mystery metal in the oil, pulled the rod bearings and they were fine. I'm not sure if he ever found out what it was.

In your case, I'd be very concerned about continuing to drive the car - not to mention doing pulls - with the engine depositing metal into the oil like you describe. Something is obviously not happy in there and I'd recommend some deeper investigation over your shops recommendation of "drive and continue to monitor." Good luck and keep your fellow N55 owners updated please.

[BruceThomas]

Hi fatty335 and All,

Here is a YT link to a very similar situation in an E39 M5. Not sure what we can take from this, but same symptoms, same actions and same outcome.........magnetic metal in the oil.

Again - I am not sure they ever find the culprit.

For my situation - I am at a cross roads and equally loss for my next step.

What do I gain by inspecting the engine? If the motor blows, I'm in for a replacement or rebuild either way.

Genuine question - do I seek to gain anything by inspecting early? If the motor blows, do I limit my rebuild options?

I am located in the Bay Area, CA so labor prices are sky high and this is not a project I could take on myself.

That being said, does anyone know any good N55 builders?

Thanks to all.

[tracer bullet]

I am guessing you've looked up all the various bearing layers, only the steel (assuming that's the thickest / backing layer on ours) should get on the magnet. So something would have to be incredibly worn to get there. I started wondering what other metals are used say on the rings, etc. and if it could be a sign of that. I don't know these engines well enough to say. Block is probably aluminum but may have steel liners?

That's the thought train I'd be considering. You could be seeing something from gear wear? Or the crank itself but again it'd be pretty serious. How's the oil pressure? Another way to look for main / rod bearing issues assuming we are squirting oil into them through small holes (as mentioned I don't know this engine in particular, I'm thinking of what I'd ask about for an older diesel engine which is what I know more about).

I think if it was from the turbo it'd have self destructed a long time ago.

Are those other particles i.e. in the filter also magnetic? Are they multicolored? This might also help think where they came from.

Just thinking out loud. Hopefully something helped.

[TWO STEP TEX]

Originally Posted by BruceThomas

Hi Guys,

Looking for any advise, guidance or anybody who has been through a similar situation.

2011 135 N55
6 MT
65K Miles
FBO
Pure Stage 2 Turbo - only installed for 600 miles
Wedge Tuning Custom Map - 91 ACN
Extensive Suspension/Handling Upgrades

I have owned the car for less than 5K miles and had the PS2 installed and all suspension/handling mods.

The car had been running stock spark plugs, but had no miss fires etc. Now replaced with NGK 97506 at .022"

Car is used only for (very) hard canyon driving.

Have been putting in 1.5 gallon of E85 per tank to help with timing corrections.

Worked with Wedge over multiple revisions to get a reliable map, suited to canyon driving, producing estimated 390ish WHP.

As of yesterday, I had the oil changed and there is considerable metal flake build up on the magnetic oil plug. See picture. No metal in the oil filter.

Oil had been previously changed when the PS2 was installed roughly 600 mile ago. I replaced the oil, as after the last drive, I got a low oil warning light.

All advise and suggestion so far has indicated the beginning of a rod bearing failure. No noises, no lights, no physical indication......yet.

With the investment I have in to the car to date, I am OK doing the rod bearings but have some questions:

1) Is there going to be any additional damage to the engine, other than the rod bearings? So are we fixing one area, for there to now be other compromised areas?

2) If I fix the rod bearings, will this just happen again? It seems a very quick demise that occurred in this instance, as the oil was changed less than 600 miles ago and no note of metal flakes then.

3) Is this an oil starvation issue from hard canyon driving? Lots of turns and lots of bumps contributing to oil bouncing everywhere? Are there any viable/proven solutions? Baffle pans? AccuSumps? Over fill?

Many thanks to everyone in advance.

The car is parked up and not moving, I would like to get the rod bearings replaced if this is sensible, but also understand the future of the motor.

Cheers,

Bruce

I was thinking about your situation and it reminded me of a video I watched where a guy discovered a code on the crank that determines what type of clearances are needed for bearings. Apparently the tolerances vary and are coded on each crank. Skip to 7:40.

Edit: watch the whole video as he talks about the rod bearings not being perfectly circular.

[BruceThomas]

Hi @TWO STEP TEX,

Thanks for the video and input.

Although rod bearings seem a semi common area to fail on modified N55 motors, it does not seem that they were the failure point on my motor.

I did find this on another forum, that could possibly explain the continued metal shavings in my oil. Attached image.

I have made the decision to run the motor until it fails. At this point, the damage is inevitably done. The bizzarness continues, as the car continues to run great. No issues.

I have sourced one or two replacement motor options, but that next hurdle/headache is establishing if a 2013 135 N55 can be swapped in to a 2011 135. I have a separate post, asking that question on here: https://www.1addicts.com/forums/show....php?t=1905343

Thanks to everyone.

[BruceThomas]

Hi Guys,

Another update.

I just had the oil replaced today.

This would be 800 miles after the last oil change and 1300 miles after the rod bearings were replaced.

There was no metal flakes on the magnetic oil plug and very few metal flakes in the filter.

There was probably 5 or 6 flakes in the oil filter compared to the last oil change that had a flake in every fold of the filter.

In the 800 miles since the last oil change - I have driven the car very hard and it has not missed a beat.

So the mystery continues. As of right now, I suspect with another oil change in 1000 miles, we might be clear of flakes.

Who knows - but it seems better news than bad news.

Thanks

[pearlpower]

Any update?

[BruceThomas]

Hi There,

Update is: car has continued to perform and drive faultlessly.

Probably another two oil changes since the last update.

No metal flakes in the filter or the magnetic plug.

I have been logging the car a lot, so plenty of WOT.

Thanks

[corbinwhit]

Hey man. So sorry to revive an old thread but I’m not sure how to pm. I’m in a very very similar situation right now. 2011 335i n55. Noticed glitter in the oil, had a shop check it out, and they recommended bearings. Paid them for the job, but now there’s still so much glitter in the oil and it’s very alarming. And my bearings looked really similar to yours. As in I don’t believe my bearings were the cause of all this metal. Car runs great oddly enough with zero codes or weird noises. I’m interested if you ever resolved this issue or figured it out.

[BruceThomas]

Hey CorbinWhit,

No problem. Finding similar real life examples can be hard.

Did I ever find the solution or culprit? Nope

But the car has continued to run great ever since then and I push it hard anytime I drive it.

Plenty of oil changes since the whole episode began, and now they run completely clear with no flakes on the plug or in the filter.

Truly bizarre.

I think in my case, it had something to do with the PS2 being installed, but that doesn’t explain much with all the factors involved.

I wish I had more helpful feedback.

Everyone’s situation is different. If it were me. You have done the RB. There isn’t much else you can get to and change from a viable cost perspective. So what option does that leave you? You might as well drive the car, do some frequent oil changes and see how they look.

Let us know how it works out?

Cheers - BT

[tracer bullet]

Originally Posted by corbinwhit

there’s still so much glitter in the oil and it’s very alarming

Any chance it's "left over"? I'd agree to do a few more changes and monitor that.

[DiamondN55]

Originally Posted by BruceThomas

Hi There,

Update is: car has continued to perform and drive faultlessly.

Probably another two oil changes since the last update.

No metal flakes in the filter or the magnetic plug.

I have been logging the car a lot, so plenty of WOT.

Thanks

Hi Bruce,

I have a spun bearing on my 2011 535i for some time and don't know who can i turn to for some advice. I'd really appreciate some help with my situation.

First of all which shop did you go to in the Bay area for the rod bearing change?

Thanks!

[E82_MDubb]

DiamondN55, if you are in the SF Bay Area, you might want to try Performance Technics out in Fremont. I know they do rod bearings. https://www.performancetechnic.com/