Is there a bottom line on S54 rod bearings?

I figured I'd make a thread, rather than jack the good S54 valve shim thread already ongoing.

I noticed in the discussion about valve shim adjustments that replacing rod bearings on the S54 came up. Having owned an E46 M3, I had heard about the recall issue, but to date, I had not heard anything about pre-emptive rod bearing replacement in later S54s.

Why and when is this necessary? Looking for some comments.

I think there was a bad supply of rod bearings that got into the first year or so of S54 engines. BMW also changed the recommended oil from 5w30 to the 10w60. I have not heard of any other rod bearing issues on S54 engines since then--despite the fact that these engines see a lot of track time.

Was the recommendation from 5w30 to 10w60 directly related to more rod bearing clearance? Were they spinning bearings prior to this?

Originally Posted by Drivewfo

Was the recommendation from 5w30 to 10w60 directly related to more rod bearing clearance? Were they spinning bearings prior to this?

Oil was changed 6/2001.
The fix on the E46 M3 was from 05/23/2003.

It was brought up in the other thread because Pal mentioned high lead readings (oil analysis) after track days.

To date, I've only swapped out the bearing inserts on S-54s in the Z3/M cars, but maybe I can talk Pal into some preventitive maintenance...

I'll probably coat this stack of bearings tomorrow (two__2__sets already spoken for):



Last batch was mostly Healey bearings:

Originally Posted by Randy Forbes

It was brought up in the other thread because Pal mentioned high lead readings (oil analysis) after track days.

To date, I've only swapped out the bearing inserts on S-54s in the Z3/M cars, but maybe I can talk Pal into some preventitive maintenance...

I'll probably coat this stack of bearings tomorrow (two__2__sets already spoken for):

Last time I saw a nice full set of rod bearings was when we changed them on an old '65 Ford Galaxie 390.

I wondered about pal's car, where the concern was coming from - I kind of deduced that it was from an oil analysis. Is increased lead specific to rod bearing wear?

So, this brings up a few more questions - I thought it was always best to change rod bearings and the crank at the same time - doing just the bearings, do you have to worry about differing wear surfaces between new bearings and the crank journals? What's the "break in" period like (duration, limits) when doing a bearing swap?

And finally, what's the coating above? How thick and how applied? Very nice work there.