[scotthilly]

Hi everyone,

I just had my rod bearings replaced with Kings bearings in my 2011 335i. I needed the OPG done and figured the bearings may as well be done - sure enough, it was only about $500 more. I feel it was worth it. Here’s some info about the car.

-94,000 miles
-OEM / Stock, besides MPPK on since 50k
-Lifetime 5-8k OCI

Attached are photos. While it didn’t need to be done, I’m happy I did. I would recommend doing it if you’re doing your OPG. I’m not sure which bearing is which cylinder as they were given to me in a bag.

Half of them are in great shape and half are just ok. Again, not sure why that would be - or perhaps they’re in totally different shape. I’m sure you all with let me know.

Anyways, hope this helps and happy to answer any questions anyone has!

[wheela]

Thanks for the data point! With the kings, did you go with oem bearing gaps (not sure if that's even an option with kings?) or did you target a larger gap?

I know next to nothing about rod bearings, but if half looked better than the other half, it seems plausible to me that the difference could be due to bottom vs. top half of bearing shell?

[fastboatster]

top bearing shells wear out quicker than bottom shells. this is because they get the most of the load during combustion stroke. your bearings look slightly worse than mine (did them at 104 kmiles)

[bmw335ie90]

Originally Posted by scotthilly

Hi everyone,

I just had my rod bearings replaced with Kings bearings in my 2011 335i. I needed the OPG done and figured the bearings may as well be done - sure enough, it was only about $500 more. I feel it was worth it. Here’s some info about the car.

-94,000 miles
-OEM / Stock, besides MPPK on since 50k
-Lifetime 5-8k OCI

Attached are photos. While it didn’t need to be done, I’m happy I did. I would recommend doing it if you’re doing your OPG. I’m not sure which bearing is which cylinder as they were given to me in a bag.

Half of them are in great shape and half are just ok. Again, not sure why that would be - or perhaps they’re in totally different shape. I’m sure you all with let me know.

Anyways, hope this helps and happy to answer any questions anyone has!

Appreciate the pics! To me this just further reinforces there is no reason to change rod bearings preventatively on well maintaned PWG N55s unless you happen to be dropping the pan for another reason.

My oil pan gasket needs to be replaced soon and I’ll probably do the rod bearings too, 105k miles now.

[oVeRdOsE.]

more and more people hitting those mileage, and more people (including bmw tech) told me I ''should'' do it...


107k miles, on a zf8, wife driven, so the car almost never see high rpm.
Liquimoly + snakeoil every 5-6k miles or so.

the engine makes a little noise a starup, but assuming this is the tensioner getting his tension.

I think Ill push it to 130-140k

[wheela]

Originally Posted by bmw335ie90

Appreciate the pics! To me this just further reinforces there is no reason to change rod bearings preventatively on well maintaned PWG N55s unless you happen to be dropping the pan for another reason.

My oil pan gasket needs to be replaced soon and I’ll probably do the rod bearings too, 105k miles now.

If you do, I hope you'll follow up with pics of the bearings! I bet they'll be okay, but still nice to see.

[wheela]

Originally Posted by oVeRdOsE.

more and more people hitting those mileage, and more people (including bmw tech) told me I ''should'' do it...


107k miles, on a zf8, wife driven, so the car almost never see high rpm.
Liquimoly + snakeoil every 5-6k miles or so.

the engine makes a little noise a starup, but assuming this is the tensioner getting his tension.

I think Ill push it to 130-140k

I bet your bearings will still be working fine until then.

I think (at least for me) the thing is if you already have the pan off, it's very small additional investment to renew the bearings while your're in there, and so very appealing. I'm x-drive, so when my oil pan eventually needs a new gasket, I'll strongly consider doing the rod bearings "while I'm in there" since that's a lot of labor getting that deep on x-drive. Only thing I hesitate about is my current bearings obviously work well, and it seems like a bit of a gamble that something could go wrong when the new bearings go in. Not sure how likely that is, but I'd hate to cause myself a problem by proactively changing bearings that could potentially gone another 100k or more. Any thoughts on that from people more experienced with n55 rod bearings?

[oVeRdOsE.]

100% if you do oil pan gasket on a x-drive you do rod bearings.

I'm on a point where I have a quite ''rare'' F25 , loaded (with m pack, access, cic, sport pack, leather) and also optional interior and exterior color.

The car is super clean, no rust.

But I'm on 170k km, and I put no money ;

- brake need to be done 4 corners
- shocks 4 corners, I have 1 leaking
- tires need to be changed
- N55 is stock, including gaskets, acc belt, pump, sparkplug, etc.

The only maintenance is oils (everywhere, including transmission) and filters.


Classic : do I put 6k$ cad in maintenance the upcoming years, or sell it while there's no check engine...


I might do the maintenance, since there's not much more interesting on the market for the price.

[whyzee125]

I did my N54 bearings at 93k miles and they looked almost identical. It had 15k oil changes until 60k and its second owner. Tuned at 21psi on full e85 ever since.

Same conclusion by the shop that did it and me: it wasn't about to blow up but I'm still glad I did it.