Age old Q..when to replace your rod bearings?

I just acquired a 2023 E93 with 80k miles and the rod bearings have not been replaced. The previous owner, who has hopefully taken good care of the car with regular oil changes, and proper maintenance, was told to get these done around the 100k mile mark.

I am inclined to go ahead and do this as this is one item that may cause a catastrophic failure without warning.

But I think BMW in late 2011 changed the bearings which should help somewhat but I am still inclined to get them changed.

What have you guys seen, and what have you done with respect to changing the rod bearings.

Any other service you would perform while doing the bearing service?

I was in a similar boat, but with a 2010 at 87k and older bearing design, and did them right away. I just wanted that worry behind me. My throttle actuators were already done. So that is all I did when I got it. Since then, I've taken care of valve covers and vanos covers as well.

I hate that the valve covers were done but not the Vanos covers. You would think that would have been a no brainer. I may look into the oil cap to see if I can tell what kind of shape at least one of them is....I will also inquire with my shop when I have chosen one for the rod bearings to see what they say.

That is odd. That is part of the reason that when I looked for my M3, I didn't care about whether the bearings and other key maintenance items were done. I wanted a well maintained car, but I like knowing that the major items were done under my watch the way I wanted them completed.

I'm on my second E92 M3, one of them I had the rod bearings replaced (~68k miles), and the one I currently have had them done around 90k miles. Both times the bearings were in pretty good condition, but for my own personal peace of mind, I would just get them changed the second I bought one no matter the mileage (assuming they hadn't been changed yet). Even with documented frequent oil changes, there's just no way to be sure that the previous owner took special care to keep the RPM's very low until the oil was up to temp every time they drove it. I'd rather pay the few thousand dollars on the front end for complete peace of mind.

BMW did change the bearings in 2011, so they are supposedly better than previous years, but overall they still have the same issue, or at least are susceptible to it.

right before they fail, duh.

tdott wrote

right before they fail, duh.

You read my mind..lol..but just to be safe I am leaning towards getting them done, along with the engine mounts and DCT services as well.

The car should be arrinving in the next few days...keeping my finders crossed it is as good as I hope it should be.

Stock RBs at 80k miles are due for change.

Redd wrote

Stock RBs at 80k miles are due for change.

I agee..just got the car on Friday and the previous owner has taken great care of the car as far as I can tell, and he informed me that the RB hadn't been done so this is not a surprise. I think I will feel better after this, and the engine mounts are done.

I bought my car at 18k miles and just did the bearings then. It gave me a 'done and forget about it mentality'. I can put 80-100k miles now without worry and just enjoy the car, obviously with proper warm up sequence, etc.

If I was the only owner and knew the car was always properly warmed then I would prob wait till around the 80-100k mile mark. There's a stock single owner 350k mi car on the forums with extensive maintenance history running stock bearings up until recently when the second owner got it

Age old Q..when to replace your rod bearings?

WBMWKID wrote

I just acquired a 2023 E93 with 80k miles and the rod bearings have not been replaced. The previous owner, who has hopefully taken good care of the car with regular oil changes, and proper maintenance, was told to get these done around the 100k mile mark. I am inclined to go ahead and do this as this is one item that may cause a catastrophic failure without warning. But I think BMW in late 2011 changed the bearings which should help somewhat but I am still inclined to get them changed. What have you guys seen, and what have you done with respect to changing the rod bearings. Any other service you would perform while doing the bearing service?

For peace of mind, and also for preventive maintenance, my advice is to replace the rod bearings now. It's possible they will last longer but also possible they will not. Due to tolerance stack up causing variation in rod bearing clearances, among the S65 engines, it becomes a big gamble. Better to be safe than sorry. See the Official Rod Bearing Example thread https://www.m3post.com/forums/showthread.php?t=1253084. The forum community has seen the rod bearings fail from ~30K miles and up. The replacement gold standard is to use B.E. Bearings with B.E. rod bolts (by ARP) if you can find any available in stock. If not they can be per-ordered online at https://www.bebearings.com/Overview.html While doing the bearing service it's advisable to change the engine mounts.

I bought my 2008 with 32K miles this summer. I did mine the first month I had the car. I like not having to worry about it.

Just got the car back - it took quite a while to get the job done - we had a little issue with the chain on the oil pump not being "lashed" correctly. But give it to the shop - I took the car back and told them i would appreciate relashing the chain - they did so without any fuss - and luckily they did have another e93 in the shop to reference - and mine sounded like it had a super charger under the hood and was quite a bit louder than the other one. But all is good now and the old rod bearing were in great shape - which lends to the fact the previous owner said he took good care - which appears that he did.

Where’s the go-to in North Georgia/Upstate SC/ Western NC? The last shop I used for RB service is no more.

spazzyfry123 wrote

Where’s the go-to in North Georgia/Upstate SC/ Western NC? The last shop I used for RB service is no more.

Harrison Motorsports in Alpharetta is a trusted shop. As close to N GA that I know of.