Quick questions on rod bearings

Leonardo629 · 09-17-2015, 03:52 AM

yes, the move away from lead is to comply with new EU rules, but the new 702/703 bearings also have greater clearance and eccentricity (for hot oil to escape) compare to the leaded bearings. Of course no one knows if it has to do with bearing material changes, or if the new bearings automatically mean longer engine life.

I'm keeping my M3 for a long time, and I'll continue to advocate lighter oil than 10W60 (I'm a M1 0W40 user), and care to warm up before I push the engine.

Killerfish2012 · 09-17-2015, 06:45 AM

Quote:

Originally Posted by Leonardo629

I'm keeping my M3 for a long time, and I'll continue to advocate lighter oil than 10W60 (I'm a M1 0W40 user), and care to warm up before I push the engine.

As long as the engine was assembled correctly, oil change intervals matter way more than oil weight.

Killerfish2012 · 09-17-2015, 06:54 AM

Quote:

Originally Posted by BMRLVR

Was this reply for me?

If so I'll be pulling the bottom end apart and measuring it all up as a project in my garage. Cost won't be an issue, since the labour will be free. The only thing I'll have to pay for is machine work, if required and parts.

What that reply missed is the huge difference between in frame rod bearing change, and proper engine rebuilds like you are doing. In frame rod bearing changes with aftermarket bolts need honing of the rods, per the bolt manufacturer's instructions, and we have even seen a car with rods snapped in half after in frame work. The proper way to do it is the way you plan on doing it.

Killerfish2012 · 09-17-2015, 06:59 AM

Quote:

Originally Posted by jin

And they are still failing?

You're digging in the wrong area, and you missed the point of my picture. Most of the '08s and '09s mileage between 100K, and 250K are on oem bearings, showing that the issue has less to do with just the bearing manufacturing. There are so many other ignored factors at play here, one of the biggest being engine assembly. Your original question had to do with vehicles with 70K or more miles. These engines are green, i.e clear of assembly issues. If proper maintenance was observed with these engines, they should have practically had lifetime bearings.

pbonsalb · 09-17-2015, 07:59 AM

Bearings have failed on cars that followed BMW's prescribed maintenance. That is the maintenance BMW considered proper. Individuals have their own version of what is proper. Some warm up the car for 15 minutes before driving. Is that proper? Some change the oil every 3k miles with new synthetic. Is that proper? Some change the oil weight from what BMW originally specified. Is that proper? Some think the car must be redlined a lot to thin the oil out. Is that proper? Some think the car must be driven gently and never run at high rpm. Is that proper?

I completely agree that the vast majority of M3, regardless of whatever maintenance was followed, seem to be doing fine on their original rod bearings. However, of those that have failed, no one has been able to draw any correlation to any particular maintenance procedure, driving style, geographical location, or oil used.

You might as well say that you have tracked your car 7 times in the year that you have owned it and your rod bearings are fine. Therefore, anyone who buys a used M3 with 95k miles and then tracks it 7 times in the first year will have no issues with rod bearings.

We really do not know what it takes to have an M3 with great rod bearings at 100k or 200k miles. Not that many of these cars seem to be in that mileage range. And even fewer are one owner cars where the maintenance and driving styles for the life of the car are known.

What I see from all the reports here is that 95% of the bearings removed from cars don't look great. That is just an opinion and I am not a bearing expert, but what I think does not look great generally matches up with what much more knowledgeable people here think does not look great so I am comfortable with my opinion. And I did my rod bearings and some had copper showing around the parting lines and by all accounts there should be no copper showing on 60k mile bearings. After copper comes steel and once you get to the steel you are looking at regrinding the crank and that is pretty much an engine rebuild.

Mr. Liu · 09-17-2015, 10:16 AM

Do we really know when exactly they switched over to the aluminum based bearings? Not vehicle year, since 2011 spanned from 2010 build dates all the way up to end of 2011....

Killerfish2012 · 09-17-2015, 11:04 AM

Quote:

Originally Posted by pbonsalb

Bearings have failed on cars that followed BMW's prescribed maintenance. That is the maintenance BMW considered proper. Individuals have their own version of what is proper. Some warm up the car for 15 minutes before driving. Is that proper? Some change the oil every 3k miles with new synthetic. Is that proper? Some change the oil weight from what BMW originally specified. Is that proper? Some think the car must be redlined a lot to thin the oil out. Is that proper? Some think the car must be driven gently and never run at high rpm. Is that proper?.

It's called planned obsolescence. Look up the term, and do some reading. You know what proper maintenance is. According to you, it's change the rod bearings after your warranty is up, and switch to M1 0W40. I beg to differ on trying to negate the risks of in-frame rod bearing changes, as it is obviously not what even the aftermarket companies who made the bearings recommend.

Quote:

Originally Posted by pbonsalb

I completely agree that the vast majority of M3, regardless of whatever maintenance was followed, seem to be doing fine on their original rod bearings. However, of those that have failed, no one has been able to draw any correlation to any particular maintenance procedure, driving style, geographical location, or oil used.

Again the vast majority of failed engines were simply improperly manufactured. I agree that drawing correlations on individual maintenance procedures is as dumb as drawing conclusions of the cosmetic appearance of the lifetime oem bearings based on pictures from randomly pulled mileages. That's like saying: “four of my upper shells showed higher than normal wear”, when it is impossible to establish a baseline wear pattern, at any particular mileage.

Quote:

Originally Posted by pbonsalb

You might as well say that you have tracked your car 7 times in the year that you have owned it and your rod bearings are fine. Therefore, anyone who buys a used M3 with 95k miles and then tracks it 7 times in the first year will have no issues with rod bearings.

The probability of engine failure on this engine is inversely related to mileage. Who knew?

Quote:

Originally Posted by pbonsalb

We really do not know what it takes to have an M3 with great rod bearings at 100k or 200k miles. Not that many of these cars seem to be in that mileage range. And even fewer are one owner cars where the maintenance and driving styles for the life of the car are known.

My previous owner would say that his indy shop told him to switch to M1 high mileage 10W40 to ensure his car ran fine up to high mileage. Thank goodness he is like the vast majority of owners who don't go online. Can you image the amount of crap from folks on here he'd have gotten? Especially from those- M1 0W40 is a religion people. Fortunately he listens to veteran mechanics, and not laptop car engineers.

Quote:

Originally Posted by pbonsalb

What I see from all the reports here is that 95% of the bearings removed from cars don't look great. That is just an opinion and I am not a bearing expert, but what I think does not look great generally matches up with what much more knowledgeable people here think does not look great so I am comfortable with my opinion. And I did my rod bearings and some had copper showing around the parting lines and by all accounts there should be no copper showing on 60k mile bearings. After copper comes steel and once you get to the steel you are looking at regrinding the crank and that is pretty much an engine rebuild.

Again, this is the crap that the aftermarket part manufactures used to scare up sales, of their product, which should only be used for proper engine rebuilding, not in frame changes. The vast majority of M3's, especially the ultra high mileage '08s/'09s are living proof that the cosmetic appearance of a "properly installed" lifetime engine component, should be ignored.

Leonardo629 · 09-17-2015, 11:25 AM

killerfish is 10W40HM what you are running right now?

squartus · 09-17-2015, 12:04 PM

Can take mine for example, oil changes at 7.5k never tracked oil always at operating temp before going over 3k rpm. Pre supercharged at 30k bearings were worn through to the copper.
Can take care of the car all you want, do what your suppose to do. If you got a engine with bad clearance/torque specs or whatever it is from factory your going to have bearing issues unless its addressed.
Some will make it over 100k fine, some wont even make it to 20k. All I can say is make your own decisions, and take trolls with a grain of salt. Failures and bearing wear are coming from every type of oil change intervul, driving habbit etc.

Been running WPC treated bearings and ARP rod bolts for 16k, just did blackstone report and shes looking great. Runs great, hopefully she holds till 150k when I plan on doing a full rebuild.

Killerfish2012 · 09-17-2015, 12:10 PM

Quote:

Originally Posted by squartus

Can take mine for example, oil changes at 7.5k never tracked oil always at operating temp before going over 3k rpm. Pre supercharged at 30k bearings were worn through to the copper.
Can take care of the car all you want, do what your suppose to do. If you got a engine with bad clearance/torque specs or whatever it is from factory your going to have bearing issues unless its addressed.
Some will make it over 200kMiles fine, Like this fine example here:

some wont even make it to 20k. All I can say is make your own decisions, and take trolls with a grain of salt. Failures and bearing wear are coming from every type of oil change intervul, driving habbit etc.

Been running WPC treated bearings and ARP rod bolts for 16k, just did blackstone report and shes looking great. Runs great, hopefully she holds till 150k when I plan on doing a full rebuild.

Fixed.

Killerfish2012 · 09-17-2015, 12:11 PM

Quote:

Originally Posted by Leonardo629

killerfish is 10W40HM what you are running right now?

I daily drive and track the vehicle in a climate with winters below 0F, so I run Total Racing 10W50 in the summer, and M1 0W40 in the winter.

jin · 09-17-2015, 06:31 PM