[9krpmrx8]

Originally Posted by Pladi

again you are missing the point.. You have a headache you take Tylenol and no more headache you are not dealing with the root cause. Your headache will return. If you know for sure that the bearings are bad thats when you do that type of work.. who here has proved that. So replacing bearings "proactively" does not necessarily solve the root cause. Your new bearings will have the same potential of failure if you have not dealt with the root cause..

I'm just saying that replacing rod bearings is not that complicated.

I don't think there is any root cause, just because you have a few guys who have spun bearings on modified cars doesn't mean there is an issue with the engine, there are a shit ton of variables. There were thousands upon thousands of N55's produced so these failures are a non issue as you have no data to indicate that any of them are related to one failure mode.

[Pladi]

Originally Posted by bbnks2

I see BMW spec'd these motors for rod bearing clearances of .00135". Most engine builders would spec a 20wt oil for that tight of a tolerance... S65 engines have the same type of pre-mature bearing wear with the same tight clearance spec and they change their bearings every 60k as a preventative measure. BMW is now putting 30wt oil into those motors vs their old recommendation of 60wt.

I think this may become a future recommendation with N55 motors too... Many engine builders are grinding down cranks and running .002" - .003" rod bearing clearances which is better suited to 40wt oils and high load engines. We very well could be seeing intermittent oil starvation causing bearing wear over time. Particularly, in left hand sweepers. Once the bearing get's worn down past its hard out layer, which we have seen plenty of motors show bearings down to the copper, they will over-heat and melt to the crank. Not much you can do about oiling except maybe run a thinner oil, but you can surely polish the crank and throw in new bearings in a few hours as a maintenance thing for <$150.

Changing rod bearings is not rocket science. I think we would see 100x more engines have this work done if it didn't involve so much work to get the oil pan off. Once the pan is off all you have to do is remove the rad caps and swap the bearings. There is nothing to "get wrong" except mixing up the rod caps or something. The only reason why rod bearing clearance would be out of spec is because you have a rotating assembly problem. This is hardly something someone swapping rod bearings should encounter, but it would damn nice to catch an out of spec rotating assembly before a seized motor!

The tight bearing clearance is the reason i never anymore use weight 40 on this motor. Even if replacing the rod bearings is not that much work in my opinion its not worth any risk if you have a working engine..

But please someone do it id love to see the results.

[Pladi]

Originally Posted by 9krpmrx8

I'm just saying that replacing rod bearings is not that complicated.

I don't think there is any root cause, just because you have a few guys who have spun bearings on modified cars doesn't mean there is an issue with the engine, there are a shit ton of variables. There were thousands upon thousands of N55's produced so these failures are a non issue as you have no data to indicate that any of them are related to one failure mode.

Yes i could not agree more. I I have said this on the other thread. Hence why i also say that this "preventative maintenance" work is not necessary. Unless you knew your car was assembled at a location that has put "wrong bearings" " bad torque" etc..

[lwgrenier]

Originally Posted by Pladi

The tight bearing clearance is the reason i never anymore use weight 40 on this motor. Even if replacing the rod bearings is not that much work in my opinion its not worth any risk if you have a working engine..

But please someone do it id love to see the results.

Why don't you used weight 40? I just changed my oil to 0w40 castrol edge. It said it was LL01 approved so I figured it would be fine. How does the weight potentially effect bearing wear? I'm a bit of a car noob.

[9krpmrx8]

LL01 means nothing unless you are following factory oil change intervals. 0W-40 is fine, I have been using M1 0W-40 since day one and have have it tested a couple of times a year and at 95k my test result still look fine.

[Welcome to NBA Jam]

Originally Posted by bbnks2

Changing rod bearings is not rocket science. I think we would see 100x more engines have this work done if it didn't involve so much work to get the oil pan off. Once the pan is off all you have to do is remove the rad caps and swap the bearings. There is nothing to "get wrong" except mixing up the rod caps or something.

There are certainly things you can get wrong. In order to do it properly, you'll need a Plastigauge to start. You'll have to follow the tolerances required by the factory.

Replacing rod bearings itself is not a mechanically difficult task, but like painting, it requires a lot of prep work and measuring. That's where most mistakes happen.

https://www.newtis.info/tisv2/a/en/e...rings/Cz2CUvNY

[Ozzie335i]

bbinks took it exactly where I was going with this discussion. I agree that oil starvation over time may, for Pladi... MAY, be resulting in premature bearing wear. Lets be real, most likely it is. And isn't that what typically causes this condition? Several reasons were given. Among them thicker original "recomended" oil, which was hinted at may not flow as well in engines with uber tight clearances. Glad I am running 5 - 30.

Another reason is fuel in the oil, thus on a momentary basis keeping oil from lubricating the moving components ala leaky N54 fuel injectors. I initially ran a Dinan stage 3 tune, which I was told was too rich. In this condition how much fuel actually ends up in the oil versus out the exhaust? And if any ends up in the oil, how much is too much? On the excel sheet I noticed different power levels. The 500 + hp guys no doubt worked their way up. Early on could they have had a rich condition that led to slight wear that over time progressively got worse until... bang. The guys at the lower power levels just may have been in a rich condition longer period of time before they could tweak the AFR properly. Not saying this is it, but as it isn't just engines built way up, is this Pladiable?

I brought up cold ambient temperatures since we all know when it is real cold the viscosity thickens. I have lived in the south for 40 years now, but when up north I recall oil heaters. If very cold starts can not possibly cause engine damage, why did the device exist in the first place? My bringing up proactively changing them out is not for the hell of it. It is because they don't go from perfect working condition to the point where they spin overnight. Agreed that a result of an oil test would indicate if such a measure may be necessary. Sorry, but if there is copper in my oil I won't be waiting around until someone finds out the root cause of why it got there before taking action. This seem to be occurring on 2011s so far. I'd consider 9 of the same year engines only, as a trend. Provided the clearances are the same with later N55s I'd have to believe that this may be as simple as an issue with the material used in the sintering process. Something that BMW absolutely would never ever admit to. Changing out said bearings that in an oil test indicates appear to be failing with newer ones may minimize the risk / exposure. I have no idea how to reference this, but are the part numbers for rod bearings for a 2011 and a 2012 the same? If different, why?

[SnapCoupe]

Originally Posted by bbnks2

I see BMW spec'd these motors for rod bearing clearances of .00135". Most engine builders would spec a 20wt oil for that tight of a tolerance... S65 engines have the same type of pre-mature bearing wear with the same tight clearance spec and they change their bearings every 60k as a preventative measure. BMW is now putting 30wt oil into those motors vs their old recommendation of 60wt.

Where are you seeing/hearing this in regards to 30 weight being used in the S65? We have never put anything other than the recommended BMW branded 10W-60 in the S54, S65, S85, and some S62s. We also still use 5W-30 in everything else up to halfway through 2017 model year cars. The 2017 and a half+ model year cars use 0W-20 and 0W-30.

[Pladi]

Guys BBNKS2 brings up excellent points. I personally started researching about the two approved weights 30 and 40 about a year ago. And pretty much came to the conclusion that the 30 weight is better for tight tolerance engines for obvious reasons. A good 30 weight oil with the good additive package will surpass 40 weight in shear protection. Not to mention it flows better and provides good cooling. Now do i think someone who is using 40 weight will have issues ? No i cannot say that. All i believe is that 30 weight is better suited for this engine. It just makes sense. No scientific experiments to back up...

I was sold with BMW 5W-30 weight after watching this test. The same guy tests many 40 weight oils including 5W-40 form liqui moly. The BMW test surpasses most tests he has done over 100..

That is a simple test but very meaningful test.

[Pladi]

Originally Posted by Ozzie335i

bbinks took it exactly where I was going with this discussion. I agree that oil starvation over time may, for Pladi... MAY, be resulting in premature bearing wear. Lets be real, most likely it is. And isn't that what typically causes this condition? Several reasons were given. Among them thicker original "recomended" oil, which was hinted at may not flow as well in engines with uber tight clearances. Glad I am running 5 - 30.

Another reason is fuel in the oil, thus on a momentary basis keeping oil from lubricating the moving components ala leaky N54 fuel injectors. I initially ran a Dinan stage 3 tune, which I was told was too rich. In this condition how much fuel actually ends up in the oil versus out the exhaust? And if any ends up in the oil, how much is too much? On the excel sheet I noticed different power levels. The 500 + hp guys no doubt worked their way up. Early on could they have had a rich condition that led to slight wear that over time progressively got worse until... bang. The guys at the lower power levels just may have been in a rich condition longer period of time before they could tweak the AFR properly. Not saying this is it, but as it isn't just engines built way up, is this Pladiable?

I brought up cold ambient temperatures since we all know when it is real cold the viscosity thickens. I have lived in the south for 40 years now, but when up north I recall oil heaters. If very cold starts can not possibly cause engine damage, why did the device exist in the first place? My bringing up proactively changing them out is not for the hell of it. It is because they don't go from perfect working condition to the point where they spin overnight. Agreed that a result of an oil test would indicate if such a measure may be necessary. Sorry, but if there is copper in my oil I won't be waiting around until someone finds out the root cause of why it got there before taking action. This seem to be occurring on 2011s so far. I'd consider 9 of the same year engines only, as a trend. Provided the clearances are the same with later N55s I'd have to believe that this may be as simple as an issue with the material used in the sintering process. Something that BMW absolutely would never ever admit to. Changing out said bearings that in an oil test indicates appear to be failing with newer ones may minimize the risk / exposure. I have no idea how to reference this, but are the part numbers for rod bearings for a 2011 and a 2012 the same? If different, why?

My personal theory is that "KNOCK" is destroying these bearings. These engines have corrections on stock maps of up to 3 degrees per cylinder. Do that over and over and over you are bound to cause mechanical stress. This is with recommended 91 octane gas. Ad to that tunes and more boost.. more knock. If you notice almost all engines that saw issues had some sort of tune running. So i personally think that you have to do absolutely everything to keep the corrections down, is the way to go to protect this engine.

[bbnks2]

Originally Posted by SnapCoupe

Where are you seeing/hearing this in regards to 30 weight being used in the S65? We have never put anything other than the recommended BMW branded 10W-60 in the S54, S65, S85, and some S62s. We also still use 5W-30 in everything else up to halfway through 2017 model year cars. The 2017 and a half+ model year cars use 0W-20 and 0W-30.

Per BMW any ll-01 is good for the s65
https://www.m3post.com/forums/attach...4&d=1381119577

I could be wrong, but I personally believe you're better off with a ll-01 30wt than a ll-01 40wt. Both will have a high hths rating of 3.5cP but the 30wt will flow better. Bearing clearances are what they are... .00135" is a very tight tolerance and BMW seems to be using it on all their motors. Why do they use 0-20 in new motors and 10-60 in older motors when they both have the same tolerances? I'm asking... If you Google you will find that 20-30wt is what is recommended for these specs. Maybe BMW knows a bit more about oiling their motors than I do though lol I would definitely like to hear the logic!

[9krpmrx8]

Science.

[SnapCoupe]

Originally Posted by bbnks2

Per BMW any ll-01 is good for the s65
https://www.m3post.com/forums/attach...4&d=1381119577

I could be wrong, but I personally believe you're better off with a ll-01 30wt than a ll-01 40wt. Both will have a high hths rating of 3.5cP but the 30wt will flow better. Bearing clearances are what they are... .00135" is a very tight tolerance and BMW seems to be using it on all their motors. Why do they use 0-20 in new motors and 10-60 in older motors when they both have the same tolerances? I'm asking... If you Google you will find that 20-30wt is what is recommended for these specs. Maybe BMW knows a bit more about oiling their motors than I do though lol I would definitely like to hear the logic!

They only use the 0W-20 and 0W-30 in motors that would've used 5W-30. I have been told that the reason behind this change was for temperature and climate variables. BMW only used 10W-60 in the high revving NA cars, which were replaced by the turbo motors that first started off using 5W-30. From the BMW techs I have worked with over the years, it seems the general consensus was that the 10W-60 just works better at higher revs (S54, S65, S85).

My Z4M coupe had 10W-60 oil changes every 12k miles up to 80k miles before I took ownership of it, then I shortened the interval to 8k between changes. At 105k I adjusted the valves and had to pop the motor open. It looked brand spanking new inside.

[katatonia]

My build date is 10/10 so this is pretty anxiety inducing lol

[xxMike61]

https://ig.me/btOfMP7QcdHi4u

Found an F30 N55 that developed knock after an OFHG change hmm

[CoffeeBean]

Those of you who have had failures, can you give exactly what oil you were using? What is everyone's thoughts on the Castrol Edge 0w-40 European formula? Wondering if 40 is too thick for the clearances.

[lwgrenier]

Originally Posted by CoffeeBean

Those of you who have had failures, can you give exactly what oil you were using? What is everyone's thoughts on the Castrol Edge 0w-40 European formula? Wondering if 40 is too thick for the clearances.

I'm currently running it with no issues. I will switch to 30 wt next oil change though. Was going to send an analysis to blackstone when my kit arrives.

[Pladi]

Originally Posted by CoffeeBean

Those of you who have had failures, can you give exactly what oil you were using? What is everyone's thoughts on the Castrol Edge 0w-40 European formula? Wondering if 40 is too thick for the clearances.

We will wonder till the end of time. So no one here has an answer for that but some knowledge from some of us that have assembled short blocks raises questions. I re built a mazdapseed 3 engine bottom up. The bearing clearances for that motor were 0.0025 and we used 40 weight. Factory 30 weight recommended. BMW has tighter clearance and now new BMW engines recommend 0w-20. Everything points to not using 0w-40. Also there is nothing 0w-40 can do that 0w-30 or 5w-30 wont be able to do.. There is no reason in my opinion to use 40 weight oil..Its not "BETTER" this is maybe true with older cars and oil.. where modifiers were not as advanced. Todays 5w-30 specs for VI and HTS and other specs are just as good as 40 weight..

[CoffeeBean]

Originally Posted by Pladi

We will wonder till the end of time. So no one here has an answer for that but some knowledge from some of us that have assembled short blocks raises questions. I re built a mazdapseed 3 engine bottom up. The bearing clearances for that motor were 0.0025 and we used 40 weight. Factory 30 weight recommended. BMW has tighter clearance and now new BMW engines recommend 0w-20. Everything points to not using 0w-40. Also there is nothing 0w-40 can do that 0w-30 or 5w-30 wont be able to do.. There is no reason in my opinion to use 40 weight oil..Its not "BETTER" this is maybe true with older cars and oil.. where modifiers were not as advanced. Todays 5w-30 specs for VI and HTS and other specs are just as good as 40 weight..

Yeah I think 40 is probably overkill unless you're tracking it all the time, but then I wonder about the bearing clearances. A bit of a catch 22. Reason I used it in my old N54 was obviously the Euro formula/LL-01 but it was always available at Wal-Mart and cheap. Castrol does make a 0w-30 Euro that's LL-01, but you'd have to order it.

FCP Euro has Liqui-Moly 5w30 with Mann filter for $62, so I may be going that route.

[Pladi]

Originally Posted by CoffeeBean

Yeah I think 40 is probably overkill unless you're tracking it all the time, but then I wonder about the bearing clearances. A bit of a catch 22. Reason I used it in my old N54 was obviously the Euro formula/LL-01 but it was always available at Wal-Mart and cheap. Castrol does make a 0w-30 Euro that's LL-01, but you'd have to order it.

FCP Euro has Liqui-Moly 5w30 with Mann filter for $62, so I may be going that route.

Yeah makes sense. Essentially 5W-30 seems to be the middle ground. I would not put 0W-20 it just doesn't have the performance for spirited driving. And 5w-40 seems a bit extreme for normal day to day. Also 5W-30 is so common and many options out there. Liqui Moly Special Tec 5w-30 probably very good oil..

[fatty335]

Originally Posted by Pladi

Yeah makes sense. Essentially 5W-30 seems to be the middle ground. I would not put 0W-20 it just doesn't have the performance for spirited driving. And 5w-40 seems a bit extreme for normal day to day. Also 5W-30 is so common and many options out there. Liqui Moly Special Tec 5w-30 probably very good oil..

Very, very little difference between these oil grades when at operating temp. I would be extremely surprised if Xw30 vs. Xw40 is in any way causal to these failures. Old oil, low oil, fuel or meth or coolant diluted oil, or some form of oil starvation are much more likely culprits.

[rich_mane]

I'm in no way an expert in this topic but I was researching oils quite a bit before making a decision on what to use. And from what I was reading, the Castrol European formula 0w30 is on the heavy side of a 30 weight, and the 0w40 is on the light side of a 40 weight. They have a minimal viscosity difference at operating temperature. I used the 0w40 Castrol on my last oil change.

I had always run BMW 5w30 up until that point. Maybe I'll just switch back on the next change. Been doing less long drives and more short trips and the thinner oil might be better for me I think.