[LoganN55]

Hello everybody, I recently acquired a 2011 f10 535. The car has 191k miles and i don't believe the rod bearings have been changed. I plan to replace them in the next couple thousand miles. The car in nearly perfect and has been meticulously maintained by the previous owner and not drove hard. Should I be scared to death like I am currently? Are the failures as common as people say? And before you say there are lots of forum posts on this, i am asking about the mileage aspect of this. I'm just scared that I have a inevitable failure about to happen

[StradaRedlands]

Get an engine oil analysis from Blackstone... they'll tell you if there is high brass or whatever in the sample. If everything comes back good, you can be relieved! Or if they're high, jump into action!

[LoganN55]

Originally Posted by StradaRedlands

Get an engine oil analysis from Blackstone... they'll tell you if there is high brass or whatever in the sample. If everything comes back good, you can be relieved! Or if they're high, jump into action!

Thank you very much for the response, this is helpful. I'll go ahead and make this my game plan!

[StradaRedlands]

Originally Posted by LoganN55

Thank you very much for the response, this is helpful. I'll go ahead and make this my game plan!

Their analysis is VERY detailed, so they'll let you know if anything looks bad based on the results. Plus good to get that done on any new to you car just to establish a base line. Hopefully no issues!!!

[Surly73]

Just a note of caution, N55 rod bearings are G-444 and G-488 lead free materials. I do believe I have read that there is still copper in their construction, so if Blackstone can detect the copper appropriate in their process you may still get indications of bearing wear. Blackstone's commentary may or may not be based on specific knowledge of the materials used in our engines. (they might be looking for lead, for instance, which is more traditional)

[ctcarbonari]

Originally Posted by Surly73

Just a note of caution, N55 rod bearings are G-444 and G-488 lead free materials. I do believe I have read that there is still copper in their construction, so if Blackstone can detect the copper appropriate in their process you may still get indications of bearing wear. Blackstone's commentary may or may not be based on specific knowledge of the materials used in our engines. (they might be looking for lead, for instance, which is more traditional)

That's an excellent point @ commentary/analysis specific to material composition of our N55 engine. They use "Universal Averages" and now I wonder if those averages for elements in parts per million are specific to each engine type for the typical wear that they receive.

FWIW, Here's a sample of their report (sorry the last column to right got chopped off on the scan) but it gives you an idea of what you'll receive.

Don't forget they'll do OA on transmission oil & differentials too!

+1 to Blackstone Laboratories. The best $35 ($40 now?) I spend on my Bimmer!

[LoganN55]

Well folks, unfortunately a day before the oil analysis came in the mail, another n55 needs rod bearings. I did a 50-110 pull after letting the car warm up perfectly, on a straight road. Got home, and the car idled great but started knocking lightly over 3k rpms. Glad it didn't spin a bearing, but they still have to be done. When completely cold, the motor doesn't knock at all but to be safe I trailed it to the shop I'm currently working on it in. Drained the oil and saw some brass colored metal shavings. Bearing material of course. Haven't got any farther yet. I will post my bearing condition tomorrow or the day after when I get them removed and inspected. Now the real question is why did it do this? I know that I was beating on it, and it's a high milage motor, but it has never been raced, tracked and it has been very well maintained. I waited till it was completely warmed up and on a flat road with no turns. Why would the oil pressure drop in a situation like that? It is best case scenario.

[Shrimpy]

Sorry for your possible misfortune Logan. I too also recently acquired a 2011 535i, but milage is lower (120,000). Please keep us posted with what you find.

Can you let us know the build date of your car? It will be listed on the VIN plate on the drivers side door frame. I ask this due to finding this post while reading through the forum:

https://f10.5post.com/forums/showthr...35i+temp+gauge

I have absolutely no idea if the build dates listed in Post #16 have any merit, but my car has a 06/10 build date. So far (barely a month of ownership, but around 2,200+ miles) I am hearing nothing at cold start idle or warmed up revs while driving. Good luck with getting it back on the road quickly and at NOT a huge cost!!!

[LoganN55]

Well here is the news, and to say the least, it isn't great... these are by far the worst bearings I have seen. Cylinder number 6 spun, cooked the rod and marred up the crank. It was the only one that failed(seems like a very common thing on these). I am a week into ownership of this car. But I do have a plan, because I have nothing more to lose other than time and a few hundred bucks in the name of science. I am going to polish the crank, clean up the rod, throw the new bearing in(plasti gauge it of course), locktite the back of the bearing(not to hold it in place, but rather to take up imperfections from where the bearing spun).

Some will find this as a interesting approach, as most would throw a crank in it or have it turned. But why not have a little fun and test to see if it holds another 100k? If it does, great, and if it doesn't, oh well, it's a high mileage motor and it could use a rebuild anyway. If the repair does fail, then I will document it here and possibly with a new post since this will probably be lost in time. If I don't post about it, assume the best. Wish me luck, and if anyone has any tips, let me know!

[ezaircon4jc]

Were regular oil changes done?

[LoganN55]

Originally Posted by ezaircon4jc

Were regular oil changes done?

It was owned by a man before me that had it changed at a dealer every 6k. I think that's a little high but some think it's just right. It had 1k on the last change when this happened. Not sure what oil was used since I have only had the car for a week but I believe that he used Castrol 5-30 full synthetic.

[Shrimpy]

Any updates Logan? Those bearings and journals are absolute toast. I applaud your idea for moving forward (Polish and re-bearing) so am interested in the outcome.

The overall engine condition doesn't look horrible for a high milage vehicle (discoloration and carbon/varnish build up) but to my eyes it appears that more than a few oil change intervals were well beyond 6K. If paperwork suggests otherwise, then I stand corrected.

Bought one of my kids a 2003 Chevy Tracker as a first car. It had a 2.5L V6 Suzuki engine with 76K when I bought it, and around 225K when I sold it. Oil changes were woefully inconsistent and probably 75+% were non synthetic oil changes. Looking into the oil fill hole, the internals were about the same color (brownish varnish color).

Good luck with your fix and hope it turns out well for you!!

[LoganN55]

Originally Posted by Shrimpy

Any updates Logan? Those bearings and journals are absolute toast. I applaud your idea for moving forward (Polish and re-bearing) so am interested in the outcome.

The overall engine condition doesn't look horrible for a high milage vehicle (discoloration and carbon/varnish build up) but to my eyes it appears that more than a few oil change intervals were well beyond 6K. If paperwork suggests otherwise, then I stand corrected.

Bought one of my kids a 2003 Chevy Tracker as a first car. It had a 2.5L V6 Suzuki engine with 76K when I bought it, and around 225K when I sold it. Oil changes were woefully inconsistent and probably 75+% were non synthetic oil changes. Looking into the oil fill hole, the internals were about the same color (brownish varnish color).

Good luck with your fix and hope it turns out well for you!!

Yes actually! I've been meaning post but I have been very busy. I ordered some king bearings, polished the crank, and I plastigauged it out and it was well within spec. So I put everything back together, very carefully and following the procedure almost exactly, and bonus, I did it at my trade school so I had both of my master technician teachers check my work every time I did something I haven't done before (most people don't put rod bearings in a motor in the car). Once it was back together, I primed it around 5 times within 20 mins, and then started it. It sounded great at first, but then a ticking popped up after about 20mins of idle. It freaked me out. Closely listing to it, I can assume it's a lifter, especially since it happens at half speed of the motor and is very light compared to knock. It also sounds identical to the lifter noise I had on my old n52 car occasionally. I decided to drive it and it sounds absolutely great. And no tick left to hear(it does sometimes at cold idle for a few seconds). I am currently at 500 miles since the bearings have been replaced and I have been tenderly driving the car. A little scared to get on it hard, but l would rather drive it like a grandma than not be able to at all. But overall, we are looking great.

[StradaRedlands]

This is great, LoganN55!!!!

[ps2cho]

Ain’t no way that engine had OCIs of 6k with that varnish…that’s why they spun.

[LoganN55]

Originally Posted by ps2cho

Ain’t no way that engine had OCIs of 6k with that varnish…that’s why they spun.

Well now they are 2k intervals. 1.3k miles down on the change of bearings

[LoganN55]

Well, with the new year approaching, I have a new post to share. And it involves another set of spun rod bearings. Oil pressure and level were good. Normal driving circumstances, oil temp was right below 250 before I started going above 2k rpms. Lovely. Time to drop 3k into this motor to fix it. Does anyone have any tips on what to do to increase the reliability(that isn't the s55 oil pan. Nobody can afford that)