Rod Bearing Showcase Thread

[heinzboehmer]

Ok, here we go.

211k miles. 2002 SMG convertible. I’m doing a full engine rebuild and just dropped the block, heads, pistons, and crank off at the machine shop. The piston and cylinder wear are well within spec so intend to re-ring, hone and go. The main bearings looked nearly new save for #7 that has slight wear.

I have decent maintenance history and all
major jobs were done at the dealer and show on the carfax. For non major jobs I also have Midas receipts for oil changes and a drain plug that was stripped and replaced at some point. So, yeah it was treated ok, but never looked after with an open checkbook.

I believe these to be original. Not bad I thought?

Every rod bearing, save for two, does show some sort of copper, however.

https://imgur.com/a/KjjGweU

I'm assuming those were replaced at the dealer at some point because of the 02 model year. Any idea when that was done? They look pretty good regardless.

[tlow98]

Ok, here we go.

211k miles. 2002 SMG convertible. I’m doing a full engine rebuild and just dropped the block, heads, pistons, and crank off at the machine shop. The piston and cylinder wear are well within spec so intend to re-ring, hone and go. The main bearings looked nearly new save for #7 that has slight wear.

I have decent maintenance history and all
major jobs were done at the dealer and show on the carfax. For non major jobs I also have Midas receipts for oil changes and a drain plug that was stripped and replaced at some point. So, yeah it was treated ok, but never looked after with an open checkbook.

I believe these to be original. Not bad I thought?

Every rod bearing, save for two, does show some sort of copper, however.

https://imgur.com/a/KjjGweU

[cobra]

This and vanos are the most over-hyped things on internet fora.

It's overhyped til it happens to you!

[jet_dogg]

Most of these bearings dont look all that bad at all. The S65 and S85 guys are laughing at us.

This and vanos are the most over-hyped things on internet fora.

[sapote]

The PO of my car was an older lady and they owned it for nearly 20 years, she never went above 4000rpm. I’m on original bearings at 160k and still going!

Do you know the condition of the bearings?

[thetypicalm3guy]

Most of these bearings dont look all that bad at all. The S65 and S85 guys are laughing at us.

[SeanE46]

I'd love a synopsis of driving/service habits since the cars inception for each set of these rod bearings. The massive variance in mileage spreads doesn't give us any remotely conclusive information.

Without any data these pics don't really mean much, they're just a collection of engine internals to look at like paintings on a wall.

The PO of my car was an older lady and they owned it for nearly 20 years, she never went above 4000rpm. I’m on original bearings at 160k and still going!

[DoubleSidedTape]

So basically the oil report didn’t tell you anything. Guess it’s worth just calling it an 80k-100k maintenance item like the old internet group think always said.

My post on the first page of this thread includes 6 reports over 30k miles on my previous m3 before I changed the bearings. I bought it at 150k, but the engine was not original to the car, so even though I had a fairly comprehensive service history for that car, I knew nothing about the status of the bearings.

For my current m3, like I said earlier, I bought the car, drove it home, and pretty much immediately took it apart to do all of the big 3 as well as some other work. I took a sample of oil from before the change but I don’t know if I still have it. In any case, I didn’t send it in for analysis.

[sapote]

All four of the middle cylinders had the bearings sticking to the crank, and you can see that they have contracted compared to 1 and 6.

#1 and #6 are King and Queen bearings -- they are lazy and don't work that hard.

[sapote]

So basically the oil report didn’t tell you anything. Guess it’s worth just calling it an 80k-100k maintenance item like the old internet group think always said.

No, OP's oil report was after he changed the bearing.

[repoman89]

Nope, I bought the car last fall and drove it home from California, and took it apart over the winter to overhaul everything. Here are the two reports from right after the bearing change (I also ended up replacing the cams and followers because one of the followers had been worn flat). I have driven about 1500 miles since the last oil change and it seems to drive really well, I'm waiting for about 2000 miles on this oil before I change it again and do another report.

So basically the oil report didn’t tell you anything. Guess it’s worth just calling it an 80k-100k maintenance item like the old internet group think always said.

[jet_dogg]

Sounds like you're the perfect person to spearhead this 👍

Give me a time machine.

[dukeofchen]

I'd love a synopsis of driving/service habits since the cars inception for each set of these rod bearings. The massive variance in mileage spreads doesn't give us any remotely conclusive information.

Without any data these pics don't really mean much, they're just a collection of engine internals to look at like paintings on a wall.

Sounds like you're the perfect person to spearhead this 👍

[DoubleSidedTape]

That was close. Any chance you have a Blackstone report before those were changed? Curious to see the numbers if you have them.

Nope, I bought the car last fall and drove it home from California, and took it apart over the winter to overhaul everything. Here are the two reports from right after the bearing change (I also ended up replacing the cams and followers because one of the followers had been worn flat). I have driven about 1500 miles since the last oil change and it seems to drive really well, I'm waiting for about 2000 miles on this oil before I change it again and do another report.

[jet_dogg]

I'd love a synopsis of driving/service habits since the cars inception for each set of these rod bearings. The massive variance in mileage spreads doesn't give us any remotely conclusive information.

Without any data these pics don't really mean much, they're just a collection of engine internals to look at like paintings on a wall.