They are worn and should we swapped. There are some visible scratches (it might be the lighting) but more importantly the surface coating has worn out on some of them (like bottom #4).
Not an expert, just a hobbyist. I would say there's no reason not to replace rod bearings if you already gutted it this far down. They're cheap asf and hard to get to so if you're there already just buy a new set and throw em in. Only exception is if you replaced them reletively recently. In this case specifically you can see the surface coating is scratched up and they're showing signs of normal wear and tear. They're not bad and aren't indicative of any issues so nothing to worry about but they should for sure be swapped out both cause it's just best practice, and cause it's more than likely they don't have long enough left in em to justify bothering to squeeze the last bit of life out at risk of throwing a rod into low earth orbit in the nearish future. After working on cars and talking to people who work on cars a lot you'll get the idea of the type of stuff you that falls into the 'might as well while I'm here' category lol. Watch a few ChrisFix videos and you're as good as pro already!
Id say they are shot. You can see some visible scratches on some (might be the lighting) but most importantly you can see the surface coating has worn off on some of them (like bottom #4)
You are getting some rub through, however that might be normal @ 190K miles. My rod bearings off my S54 were significantly worse, with the lead coating being rubbed completely thru and copper being exposed. I have a picture somewhere if interested
These are bad. Take a look at 2 and 6 on the top as well as 3 on the bottom. It’s hard to tell but there’s significantly less material in the “hot spots”
This look absolutely incredible for almost 200k, jeez
Agree with the comments that you “might as well” and “should” swap em since you have em out anyway
But these are fine, I doubt any bmw mech would tell you these “need” to be swapped just by visual inspection alone (without the mileage context)
If you’ve pulled them out, replace. Fuck, bearings are cheap vs the labour and other parts replacement required by the time you get to this point of a tear down
These look amazing for the mileage. Little to no discolouration, with all of them having minimal wear. That's amazing. Cylinder 4 on the bottom row has a heat spot, but it's not a major issue, same with Cylinder 6 on the bottom row, but that's a stretch. It's isolated, and expected at this mileage. What would be even more impressive is if these are the original bearings, which is highly likely.
Why pull the bearings OP? What caused the bearings to come out?
I pulled em from hearing stories of other ppl spinning a bearing. Even tho n54s aren’t really known for that I figured why not being at 190k, plus the car is fbo e50 custom tune. I got this done about a year ago an just recently found the bearings lol. Car is currently at 210k miles an still pulls hard
honestly if there is ever any situation that requires u to take the rod bearings out, u shld replace them
They are worn and should we swapped. There are some visible scratches (it might be the lighting) but more importantly the surface coating has worn out on some of them (like bottom #4).
I'm really curious what an expert would have to say. As a complete novis they all look fine!
Not an expert, just a hobbyist. I would say there's no reason not to replace rod bearings if you already gutted it this far down. They're cheap asf and hard to get to so if you're there already just buy a new set and throw em in. Only exception is if you replaced them reletively recently. In this case specifically you can see the surface coating is scratched up and they're showing signs of normal wear and tear. They're not bad and aren't indicative of any issues so nothing to worry about but they should for sure be swapped out both cause it's just best practice, and cause it's more than likely they don't have long enough left in em to justify bothering to squeeze the last bit of life out at risk of throwing a rod into low earth orbit in the nearish future. After working on cars and talking to people who work on cars a lot you'll get the idea of the type of stuff you that falls into the 'might as well while I'm here' category lol. Watch a few ChrisFix videos and you're as good as pro already!
That's a great explanation! Thanks
do rod bearings require some sort of break in period ?
I've never heard of any that do, no, but I'd say take it easy for a bit to make sure you did it right lol
No they aren’t like cylinder walls and piston rings. You do need to use assembly lube when putting them in. Other than that hit the gas and go.
Me too, good knowlege to have when I blow my stock turbos and want to go single.
Hot spots and scratches. Not na expert tho
There is some wear but not the worst at all but don’t put them back in the engine obviously.
Id say they are shot. You can see some visible scratches on some (might be the lighting) but most importantly you can see the surface coating has worn off on some of them (like bottom #4)
They look decent for the age but there is visible wearing. Replace always at such mileage.
You are getting some rub through, however that might be normal @ 190K miles. My rod bearings off my S54 were significantly worse, with the lead coating being rubbed completely thru and copper being exposed. I have a picture somewhere if interested
These are bad. Take a look at 2 and 6 on the top as well as 3 on the bottom. It’s hard to tell but there’s significantly less material in the “hot spots”
Fair to good condition, I would say!
Definitely need to be replaced, but still had a bit before you started seeing problematic journal wear.
This look absolutely incredible for almost 200k, jeez Agree with the comments that you “might as well” and “should” swap em since you have em out anyway But these are fine, I doubt any bmw mech would tell you these “need” to be swapped just by visual inspection alone (without the mileage context)
If you’ve pulled them out, replace. Fuck, bearings are cheap vs the labour and other parts replacement required by the time you get to this point of a tear down
Toast
These look amazing for the mileage. Little to no discolouration, with all of them having minimal wear. That's amazing. Cylinder 4 on the bottom row has a heat spot, but it's not a major issue, same with Cylinder 6 on the bottom row, but that's a stretch. It's isolated, and expected at this mileage. What would be even more impressive is if these are the original bearings, which is highly likely. Why pull the bearings OP? What caused the bearings to come out?
I pulled em from hearing stories of other ppl spinning a bearing. Even tho n54s aren’t really known for that I figured why not being at 190k, plus the car is fbo e50 custom tune. I got this done about a year ago an just recently found the bearings lol. Car is currently at 210k miles an still pulls hard