[Ozzie335i]

Two things that the fatman said jumped out at me:

"I figure these bearings will last me as long as I want to keep the car."

"The more pictures that get posted like this, the more I'm very happy I changed mine when I did."

I agree wholeheartedly. We all can agree that there is a bearing problem, whatever the cause. Maybe someday BMW will come clean and enlighten us. Until that day comes if we intend on keeping these fine rides we all must make risk tolerence decisions. I pegged the mileage for taking proactive measures somewhere between 60 and 70 k miles. I was at 78 k, and considering all of the go faster options I have bolted on my engine, I was getting nervous.

[fatty335]

Happy Saturday all,

Ever since I decided to install WPC-treated OE rod bearings instead of just OE or coated aftermarket bearings, I have been trying to find information on someone who has run WPC-treated bearings for some time, and then pulled them to check the wear. This information has proven very difficult to come by, especially somebody who has done this in a BMW application. Anyway, I came across the following (all credit to Paul Vo) where this guy removed WPC-treated OE bearings from his S54-equipped E46 at 15,000 miles. This is an engine that has a well documented history of worn rod bearings. So, what do you all think?

[ThatKidDavid]

In for updates
Got my 1st custom tune by wedge and 1st pull misfired, car started sounding very weird after that. To me it sounds high pitched a lot of engine sound which overpowers the exhaust and a slight sound of knock (I'm thinking) around 3k rpm. Turbo seals are done but car has new injectors, plugs, coils, hpfp, boost solenoids, and I can't help but think my rod bearings are about to go. Oil pressure is good but the car is pulling massive timing (could be due to failing turbo) but I'll try and get a video of what the car sounds like. I guess my next step would be oil analysis and vanos solenoid, but also curious could this be a jumped timing chain? Compression test and leak down test came out within spec. Lot of info I know but any help would be appreciated, so much money has gone into the car already

[Pladi]

Originally Posted by ThatKidDavid

In for updates
Got my 1st custom tune by wedge and 1st pull misfired, car started sounding very weird after that. To me it sounds high pitched a lot of engine sound which overpowers the exhaust and a slight sound of knock (I'm thinking) around 3k rpm. Turbo seals are done but car has new injectors, plugs, coils, hpfp, boost solenoids, and I can't help but think my rod bearings are about to go. Oil pressure is good but the car is pulling massive timing (could be due to failing turbo) but I'll try and get a video of what the car sounds like. I guess my next step would be oil analysis and vanos solenoid, but also curious could this be a jumped timing chain? Compression test and leak down test came out within spec. Lot of info I know but any help would be appreciated, so much money has gone into the car already

post a few logs of when the car was running good. Should tell us a good story.

Like a few logs of just before this issue

[ThatKidDavid]

Originally Posted by Pladi

post a few logs of when the car was running good. Should tell us a good story.

Like a few logs of just before this issue

https://datazap.me/u/imdavidbitch/old-log-e50-problems-i-think

[ghost135i]

Originally Posted by ThatKidDavid

https://datazap.me/u/imdavidbitch/old-log-e50-problems-i-think

Any luck with the issue?

[ThatKidDavid]

Originally Posted by ghost135i

Any luck with the issue?

Car is still sounds weird and sometimes wants to misfire when given too much throttle at low rpm. I probably put like 10k hard miles on it since after replacing every maintinance item and top end still pulls like a train. Turbo is blowing lots of oil and I keep getting this code for BOV jammed closed. Black Friday imma just go full send and buy the big boost kit 6159 bb turbo but I won't install it till I save up enough to swap out my rod bearings and valve cover gasket, while I'm in there I might as well throw in MILVS. Got big plans, hopefully I can thinks settled by 2020

[kanovic]

Originally Posted by ThatKidDavid

Car is still sounds weird and sometimes wants to misfire when given too much throttle at low rpm. I probably put like 10k hard miles on it since after replacing every maintinance item and top end still pulls like a train. Turbo is blowing lots of oil and I keep getting this code for BOV jammed closed. Black Friday imma just go full send and buy the big boost kit 6159 bb turbo but I won't install it till I save up enough to swap out my rod bearings and valve cover gasket, while I'm in there I might as well throw in MILVS. Got big plans, hopefully I can thinks settled by 2020

Curious as why not do bearing right now and save up for the turbo?

[AngelFarelli]

Bump . Just found out I need to replace oil pan so rod bearings is a consideration for me. How did the instal go? Should I replace mine with my car being at 140k miles while I have the pan off? N55 f30 2012 140k miles

[fatty335]

Originally Posted by AngelFarelli

Bump . Just found out I need to replace oil pan so rod bearings is a consideration for me. How did the instal go? Should I replace mine with my car being at 140k miles while I have the pan off? N55 f30 2012 140k miles

Hi AngelFarelli, this thread has gotten quite long but you can read about my impressions of the job on page 4. If you have any specific questions that I didn't cover there, feel free to ask. The only thing I would do differently if I were to do it again, would be to go ahead and remove the entire subframe vs. just letting it hang by the struts - would make torquing the rod bolts much easier.

Whether or not you should inspect or replace your rod bearings while the pan is down is entirely up to you. I would carefully weigh how long you plan to keep the car, its value, cost of the parts/labor, maintenance history of the car, how much power you're making, how long you can afford to be without the car, your mechanical ability, etc.

If it were my car, knowing what I know about the N55 and at 140K miles, I would not hesitate to replace the rod bearings. At the very least, I would pull a rod cap or two to inspect; that would only cost you a few new stretch bolts and 10 minutes or so.

[SCS55]

Originally Posted by lwgrenier

Right but I think the other guys want to know if the UOA is accurate so they can monitor bearing life with analysis rather than opening up the engine.

I'm in this boat. I've personally put 60,000 plus miles on my 2015 335i Msport I'm at 81,000 now and have at least 5 Blackstone reports with absolutely zero issues or questionable wear notes. I would at least get one report at a minimum and it'll go up against a data base of similar mileage N55's. But at the end of the day, it's your money.

[ghost135i]

Decided to replace mine preventatively while upgrading my turbo and a few other things so I can be worry free when beating on her.

77k miles, 3rd owner for the last 30k. Full Bolt On for the last 10k. 2012 135i.

[fatty335]

Originally Posted by ghost135i

Decided to replace mine preventatively while upgrading my turbo and a few other things so I can be worry free when beating on her.

77k miles, 3rd owner for the last 30k. Full Bolt On for the last 10k. 2012 135i.

Nicely done and thanks for posting up pics of the old ones! Just out of curiosity, what did you end up putting back in in terms of shells and bolts (OE, King, coated or non-coated, ARP etc.)?

[ghost135i]

Originally Posted by fatty335

Nicely done and thanks for posting up pics of the old ones! Just out of curiosity, what did you end up putting back in in terms of shells and bolts (OE, King, coated or non-coated, ARP etc.)?

My mechanic is doing the work. We went with King bearings, not sure of the bolts. He's built several big power forged N55s, N54s, and S55s that are running around happily at 700+ to the wheels with no issues.

Billy Mason at BMB Autowerks in Northern NJ

[daniel35d]

I'm very curious about this whole rod bearing thing with N55.

I hear every now and then about spun bearings or seized engines at under/near 100k miles.
And of course the seized engine shortly after OFHG replacement.

But not too long ago there was an F31 335i for sale here with 137k miles, and it seems to be on original bearings/engine, and I've heard of a couple others with over 100k miles on original bearings.

Is it just luck that these have lasted so long?

I've been wanting an N55 powered car since in my opinion the N54 sounds horrible and also has its fair share of issues.

But this rod bearing stuff makes me question the whole thing.

[ghost135i]

Originally Posted by daniel35d

I'm very curious about this whole rod bearing thing with N55.

I hear every now and then about spun bearings or seized engines at under/near 100k miles.
And of course the seized engine shortly after OFHG replacement.

But not too long ago there was an F31 335i for sale here with 137k miles, and it seems to be on original bearings/engine, and I've heard of a couple others with over 100k miles on original bearings.

Is it just luck that these have lasted so long?

I've been wanting an N55 powered car since in my opinion the N54 sounds horrible and also has its fair share of issues.

But this rod bearing stuff makes me question the whole thing.

From what I've seen and heard, it's honestly a fairly rare occurrence... There's of course a few cases of this on the forums happening under normal use, and the OFHG situation I would attribute to dropping debris down the oil galleys, but the only others I have heard of were cars being raced a lot pushing big power.

[fatty335]

Originally Posted by daniel35d

I'm very curious about this whole rod bearing thing with N55.

I hear every now and then about spun bearings or seized engines at under/near 100k miles.
And of course the seized engine shortly after OFHG replacement.

But not too long ago there was an F31 335i for sale here with 137k miles, and it seems to be on original bearings/engine, and I've heard of a couple others with over 100k miles on original bearings.

Is it just luck that these have lasted so long?

I've been wanting an N55 powered car since in my opinion the N54 sounds horrible and also has its fair share of issues.

But this rod bearing stuff makes me question the whole thing.

What follows are only my opinions based on my own experiences and research into the issue:

1. Both the N54 and N55 experience faster rod bearing wear than what I would expect for the miles
2. This is/was likely due to a combination of design (tight clearances for efficiency at ~.0018), extended oil drain intervals/free maintenance early on, hard driving on cold oil, and questionable tuning/mods for higher specific output
3. Obviously, every engine and owner are different and the above variables will be weighted more/less heavily in each case

For me, I bought a n55 equipped 2011 335i with ~60,000 miles on the clock and multiple previous leasees/owners and a largely unknown service history. I plan to keep the car for some time and changing the bearings made the most sense for me. I'm glad I did because at ~72,000 miles, my bearings didn't look so hot.

As for the OFHG issue (warning - more personal opinion to follow), I believe a momentary or multiple momentary oiling disruptions caused by air pockets introduced into the system during the repair worsens a preexisting worn rod bearing condition that ultimately results in the bearing failing.

This could explain why we didn't see many failures until recently and why BMW didn't release the priming SIB earlier - fresher bearings can handle it; worn bearings not so much.

Or it could be something totally different...

[daniel35d]

Originally Posted by ghost135i

From what I've seen and heard, it's honestly a fairly rare occurrence... There's of course a few cases of this on the forums happening under normal use, and the OFHG situation I would attribute to dropping debris down the oil galleys, but the only others I have heard of were cars being raced a lot pushing big power.

Well, yeah it might be fairly rare. There is quite alot of N55 cars around the world in the different series (1-7 series + some X cars). But on the other hand there are probably many failures we have NOT heard about as well.

Yes I've read some various theories about the OFHG thing. One being that coolant can have found its way in there during the job because you have to remove some lines for better access (I might be wrong here, I don't remember it 100% correctly).

Hard use, and possibly big power or poor tunes can probably contribute to this as well.

I would probably only go for a reasonable tuning since I live in a country where majority of the highest speed limits are just 50 mph (80km/h), with the exception of a few highways with 68 mph (110km/h). So there isn't really a need for any crazy tuning.

Originally Posted by fatty335

What follows are only my opinions based on my own experiences and research into the issue:

1. Both the N54 and N55 experience faster rod bearing wear than what I would expect for the miles
2. This is/was likely due to a combination of design (tight clearances for efficiency at ~.018), extended oil drain intervals/free maintenance early on, hard driving on cold oil, and questionable tuning/mods for higher specific output
3. Obviously, every engine and owner are different and the above variables will be weighted more/less heavily in each case

For me, I bought a n55 equipped 2011 335i with ~60,000 miles on the clock and multiple previous leasees/owners and a largely unknown service history. I plan to keep the car for some time and changing the bearings made the most sense for me. I'm glad I did because at ~72,000 miles, my bearings didn't look so hot.

As for the OFHG issue (warning - more personal opinion to follow), I believe a momentary or multiple momentary oiling disruptions caused by air pockets introduced into the system during the repair worsens a preexisting worn rod bearing condition that ultimately results in the bearing failing.

This could explain why we didn't see many failures until recently and why BMW didn't release the priming SIB earlier - fresher bearings can handle it; worn bearings not so much.

Or it could be something totally different...

Funny you say that. The "N54 fanboys" if you will, loves to hate on the N55 for rod bearings and random seizing, while at the same time glorifying the N54.

Yeah I'm guessing the N55 cars also have this crazy 30,000km oil change interval like most other newer BMWs have. I personally change oil on my car every 10-15,000km/1 year. Sometimes earlier than that as well.

I would most likely be looking at E9x 335i or F1x 535i when the time comes. Would probably be easier to find a 535i that haven't been modified than a 335i, but time will show.

The OFHG issue definitely seems like a mystery. Don't think I'd dare to change that myself because of this.

Are there any aftermarket options that "eliminates" the rod bearing issue, or are you just going to prepare yourself to change them again after 60-80k miles?

[fatty335]

Originally Posted by daniel35d

Are there any aftermarket options that "eliminates" the rod bearing issue, or are you just going to prepare yourself to change them again after 60-80k miles?

After weighing available options, I elected to install WPC-treated OE bearings with OE stretch bolts. Others have installed various coated bearings from different manufacturers with either OE or ARP bolts. I think my choice, along with not tuning for big power/not sending it on a cold engine/5k mile oil changes should get me the longevity I'm after for this car.

In my opinion, "eliminating" the issue would include altering the rod bearing clearances to something more traditional for our journal size (.002 - .0025) and moving to a performance oriented tri-metal bearing. Of course, this would need to be accomplished via crank machining or sourcing a bearing that would give you the increased clearance (none currently available for the n54/n55 AFAIK).

[bbnks2]

Originally Posted by fatty335

In my opinion, "eliminating" the issue would include altering the rod bearing clearances to something more traditional for our journal size (.002 - .0025) and moving to a performance oriented tri-metal bearing. Of course, this would need to be accomplished via crank machining or sourcing a bearing that would give you the increased clearance (none currently available for the n54/n55 AFAIK).

stock bearings are tri-metal

There are now several brands of bearings that offer an "x" bearing which gives you .001" more clearance (~.0025" total). Or, you can mix and match with regular bearings for +.0005" (~.002" total).

[SCS55]

Originally Posted by Kev0

I've been using Mobil/Castrol 0w40 but recently (this past weekend), my mechanic replaced my oil pan gasket due to a minor leak and he used LiquiMoly 5w40. I usually request that he uses Mobil 0w40 but since he keep LiquiMoly in stock, I decided to try it. After picking up the car yesterday, I must say that I definitely feel a difference with 5w40. I can hear the difference with cold start and the idle and drive was much smoother. Definitely not a placebo effect. Any cons running 5w40? I'm thinking about permanently switching from Mobil/Castrol 0w40 to Liqui Moly 5w40 from this experience alone.

All throw my pitch for you for Liqui Moly 5W40. Switched from Castrol 0W40 Euroblend to Liqui Moly Molygen about a year ago on 3 engines. I've be running that spec in my N55, S55, and e90 with the N52. All engines are on 5000 mile oil change intervals and every Blackstone oil report on all three come back with great numbers and positive comments such as the latest on my daughters 328i with the N52.
I hope that helps.

[SCS55]

Originally Posted by SCS55

All throw my pitch for you for Liqui Moly 5W40. Switched from Castrol 0W40 Euroblend to Liqui Moly Molygen about a year ago on 3 engines. I've be running that spec in my N55, S55, and e90 with the N52. All engines are on 5000 mile oil change intervals and every Blackstone oil report on all three come back with great numbers and positive comments such as the latest on my daughters 328i with the N52.
I hope that helps.

Forgot to add picture of oil report.