[2013F10]

I'm getting ready to replace my oil pan gasket (F10 535ix, N55) at 110k miles and am debating whether or not to replace the rod bearings. It's easy to say "while you're in there" but it's delicate work that takes extra time and money.

I've owned this car since 45k miles as a daily driver. The engine is stock, I rarely drive it hard and have changed the oil/filter every 5k miles with full synthetic BMW or Liqui-Moly oil. Is there a wear issue with F10 N55 rod bearings like in older generations?

[AlpineweissF10]

Wondering the same. My production date is March-2012. Currently at 137k miles and need to change the oil pan gasket. I am tuned on bm3 stage 1 and my oil change frequency is 5k miles.

This would be the opportune time to change them. Wouldnt want to repeat the job. It's already daunting as is.

[95blkmax]

Originally Posted by 2013F10

I'm getting ready to replace my oil pan gasket (F10 535ix, N55) at 110k miles and am debating whether or not to replace the rod bearings. It's easy to say "while you're in there" but it's delicate work that takes extra time and money.

I've owned this car since 45k miles as a daily driver. The engine is stock, I rarely drive it hard and have changed the oil/filter every 5k miles with full synthetic BMW or Liqui-Moly oil. Is there a wear issue with F10 N55 rod bearings like in older generations?

from what I've seen, it's all on driver habit and maintenance history. That first oil change is CRITICAL, and BMW screwed everyone with their BS 10k mile oil change interval. Not saying this is the only cause as there are more, but every N55 that I've seen at work come through that was seized or had nasty rod knock ALL happened to have gone over that 10k mile first scheduled oil change. 13k-18k for the first oil change is not uncommon to see on these samples.

This really sucks because as most of these are no longer owned by the first owner, and the damage doesn't become evident until years later... the ones that have to deal with the consequences are us.

Other factors are idiots that like to rev out a cold engine, or go WOT leaving their neighborhoods with the engine still cold, or using "El Cheap-o" oils from these "quick oil change" businesses like Take5 and Jiffy Lube. Obviously these factors would not be fixed by having a newer model N55 with the updated oil pump. This problem just gets worse when you are modded.

So to answer your question, the rod bearings needing to be replaced or not- totally unknown. It doesn't happen to all N55s, but if it happens to you, you'll kick yourself in the butt for not taking care of them while you had the oil pan out for the gasket! lol

I have all the parts for mine in the garage and will take care of this once the weather cools down in a couple months. I'm at about 129k. I've been changing my oil about every 2500-3000 miles (more by time than by mileage due to my short commute). But I bought the car at 109k. I have the BMW history on it up to about 60k, then a blank until 109k. So because I don't have history for a span of 50k miles, I'm doing them. Especially with as modded as I am, and being a 2011.

Hope this helps ya make your decision!

[2013F10]

Originally Posted by CoffeeBean

I assume you have a 2013. It’s really just the 2011 models that sometimes have issues. The bearings and oil pump were revised halfway through 2011 for the 2012 model.

Yep, 2013. Thanks for the clarification.

[Surly73]

I've seen a million theories, but no true conclusions with any evidence about causes of the failures or true indicators of expected life. I have an early 2011 N55 X-Drive so I'm paying attention. It also seems like there might not even be a problem - for all the N55s out there in all of the various platforms in which it was used, we're only going to hear from the people with problems.

There's high load while WOT at low temps, using oil that's too thick and doesn't lubricate bearing #6 when cold, using oil that's too thin and not providing thick enough film on all the bearings, bad luck, tighter tolerance design in newer engines, the change to lead-free environmental materials, oil journals in early blocks being too small, intervals too long, FIRST interval too long, tunes, undiagnosed super-knock blasting through the film layer, short trips, cold climates, hot climate, GTL Group III+ oils being "too dry", starvation on hard left turns, and of course recent OFHG job without priming - I feel like I've seen it all and none ring true as conclusive.

With all the extra complication of an X-Drive oil pan - I personally would be thinking about doing the rod bearings on my "long term keeper". The extra labour and complication on the X-Drive makes the "while you're in there" list longer. Failure mileage seems all over the place.

A shop that does work like this told me that they generally ditch the factory recommendations and go with a replacement bearing solution which has larger clearances "like they used to" and thereafter run 5W40 LL-01 "like they used to" worry free for hundreds of thousands more Ks.

I believe someone in one of these forums had looked at all the part numbers and revisions and concluded that the bearings were NOT redesigned, but there were several revisions to the block, potentially lending credence to the risk of oil journals being insufficient or marginal given quality control tolerances.

[2013F10]

Originally Posted by Surly73

I've seen a million theories, but no true conclusions with any evidence about causes of the failures or true indicators of expected life. I have an early 2011 N55 X-Drive so I'm paying attention. It also seems like there might not even be a problem - for all the N55s out there in all of the various platforms in which it was used, we're only going to hear from the people with problems.

There's high load while WOT at low temps, using oil that's too thick and doesn't lubricate bearing #6 when cold, using oil that's too thin and not providing thick enough film on all the bearings, bad luck, tighter tolerance design in newer engines, the change to lead-free environmental materials, oil journals in early blocks being too small, intervals too long, FIRST interval too long, tunes, undiagnosed super-knock blasting through the film layer, short trips, cold climates, hot climate, GTL Group III+ oils being "too dry", starvation on hard left turns, and of course recent OFHG job without priming - I feel like I've seen it all and none ring true as conclusive.

With all the extra complication of an X-Drive oil pan - I personally would be thinking about doing the rod bearings on my "long term keeper". The extra labour and complication on the X-Drive makes the "while you're in there" list longer. Failure mileage seems all over the place.

A shop that does work like this told me that they generally ditch the factory recommendations and go with a replacement bearing solution which has larger clearances "like they used to" and thereafter run 5W40 LL-01 "like they used to" worry free for hundreds of thousands more Ks.

I believe someone in one of these forums had looked at all the part numbers and revisions and concluded that the bearings were NOT redesigned, but there were several revisions to the block, potentially lending credence to the risk of oil journals being insufficient or marginal given quality control tolerances.

Great input, thanks for the reply. I've decided to go ahead and replace the rod bearings while doing the oil pan gasket because, as you said, the time and effort it takes to access them on an x-drive N55 makes this a very expensive stand-alone job.

[AlpineweissF10]

Originally Posted by 2013F10

Great input, thanks for the reply. I've decided to go ahead and replace the rod bearings while doing the oil pan gasket because, as you said, the time and effort it takes to access them on an x-drive N55 makes this a very expensive stand-alone job.

How bad were your rod bearings when you replaced them? I have the oil pan off the car and I'm really contemplating if I should go ahead and replace them. It's a lot of wrenching just to get to the oil pan BUT I'm exhausted and want to get the car back together without taking out more parts.

[TuunedF10]

Originally Posted by 2013F10

Great input, thanks for the reply. I've decided to go ahead and replace the rod bearings while doing the oil pan gasket because, as you said, the time and effort it takes to access them on an x-drive N55 makes this a very expensive stand-alone job.

How bad were your rod bearings when you replaced them? I have the oil pan off the car and I'm really contemplating if I should go ahead and replace them. It's a lot of wrenching just to get to the oil pan BUT I'm exhausted and want to get the car back together without taking out more parts.

These were mine at 170k