Rod Bearing Replacement w/Pics (2010 e92, 62k Miles)

[Doc Oc]

Originally Posted by JonM

My theory (and supported by Blackstone results) is: the wear happens right at the beginning.

I am the one and only owner of my car. 2008 E90M3. BMW/Castrol 10W60 every 5000 miles, DIY by me every time. When I bought the car I was already tuned up to oil analysis and bearing failures, as I had S54s in my fleet at the time. I think I was one of the first to Blackstone-test an S65. See attached. The first Blackstone report on the car was bad. The second was not good.

Now, when I test it at 60,000 miles, it looks OK.

I think the high copper and iron on the first test is just the engine breaking in and not related to your bearings. Looks like your throwing more lead now than at lower miles which indicates that bearing wear is slightly increasing.

[macdude357]

Originally Posted by JonM

My theory (and supported by Blackstone results) is: the wear happens right at the beginning.

This brings up even more questions.

Why do we see cases where bearings fail even after clean reports? If the wear only happened early on, what caused the bearings to fail unless they are worn to the point of imminent failure and just take a while to finally go?

Why would the bearings stop wearing assuming you have changed your oil regularly? Does the initial wear provide enough clearance that the wear stops at some point?

[nydog]

I'm surprised no one has any comments around the 11k - 14k oil change intervals, if I'm interpreting that statement correct. I would think that contributes to what we're seeing.

[delirium330]

Originally Posted by nydog

I'm surprised no one has any comments around the 11k - 14k oil change intervals, if I'm interpreting that statement correct. I would think that contributes to what we're seeing.

While I don't disagree that those intervals could contribute to increased bearing wear, the vast majority of M3s on the road are going to have identical intervals for at least their first 40-50k miles or however long the new car service package lasts.