Rod bearings

[AdamM3]

Plastiguage is doable on car, I dont believe you will be able to get a gauge/mic on the rod itself in the block like that though. Seems like most people just slap them in.

[Robert's_BMW]

Plastiguage is doable on car, I dont believe you will be able to get a gauge/mic on the rod itself in the block like that though. Seems like most people just slap them in.

I meant throw a micrometer on the ACL bearings to verify uniformity and plastigauge for the clearance. But reading through most rod bearing posts, it seems people just throw them in.

[01LSBM3]

I was trying to source BE Bearings but could not find them any where. It seems that bearings are becoming scarce right now. I reached to several places if anyone is looking. VAC has their coated bearings, Lang racing had a couple of sets of ACL, and Turner has the WPC/stock bearings. All three vendors were very helpful and responsive to helping me. So hopefully this will prevent someone from hours of searching if you are looking to do a DIY.

[bimmer]

Just a PSA for those of you following SYT Shadow's DIY. For the most part, it is good, but I would not follow his instructions to use RTV on both sides of the oil pan gasket. I just did my oil pan gasket recently (skipped rod bearings because of low mileage and clean Blackstone reports), and had to redo it because the new gasket still leaked. I talked to a couple BMW techs and they attributed this to putting RTV on both sides. The second time around, I used OEM Drei Bond 1209 and only put a small dab where the timing cover and rear crankshaft cover mate with the block.

Also, make sure your FCABs are fully seated before you attempt to thread the bolts in when reattaching your subframe. Do not use the bolts to guide the FCABs into place. Multiple cases of people cross threading the frame of the car by doing this (including myself).

+1 on this. Had the same issue with using RTV on the oil pan gasket after following the DIY. Indy saw the RTV/slight leaking during an alignment and tipped me off to using Hondabond as its cheaper than the BMW OEM Drei Bond and works the same. As mentioned above only use it at the mating points. You do not want to have to change the oil pan gasket after just doing it as part of the rod bearings job. It sucks and you will curse yourself for using RTV the whole time, believe me.

[JamesSJ1]

Just did my rod bearing job at 92k miles. Car had 30k miles in 9 years (oil changes approx one a year) when I bought it, and I've done changes with TWS every ~7500 miles since, plus LiquiMoly MOS2. I've attached my latest Blackstone with the history, along with pictures of the rod bearings. You can see from my oil analysis history that my car has always run relatively high lead and copper numbers. I don't think this is from the 7500mi intervals, but the consistency until the most recent one has made me comfortable with the numbers. The recent spike is likely related to the 2 months that the car sat in a shop in Oct-Nov (another story), often getting at least 2 cold starts/day to move cars around and never letting the engine warm up. It got just a few hundred miles after that before I did that oil change. Interesting that the fuel % spiked since I brought the engine up to temperature driving around before doing the oil change, but oh well. I decided with work-from-home downtime to go ahead and do the rod bearings (and other things) for peace of mind.

The bottom bearings appear good, with just a slight hint of copper starting to show.

The top bearings 1 & 2 show the most wear to copper. Check out the striking copper sheen on the edge of bearing 1.

What do you think? Full-size picture attachments are included as well for the curious that want to see some close-ups.

[Arith2]

The bottom bearings appear excellent I think, with just a slight hint of copper starting to show.

The top bearings 1 & 2 show the most wear to copper. Check out the striking copper sheen on the edge of bearing 1.

What do you think? Full-size picture attachments are included as well for the curious that want to see some close-ups.

]

That looks like some decent wear. The bottom doesn't look excellent and the top looks close to the end of its life. It's good you changed them. What's weird is most bearings seem to opposite of yours where the bottom is worn and the top looks better. I'm not sure what that's about

[JamesSJ1]

That looks like some decent wear. The bottom doesn't look excellent and the top looks close to the end of its life. It's good you changed them. What's weird is most bearings seem to opposite of yours where the bottom is worn and the top looks better. I'm not sure what that's about

I just looked at a couple other pictures. I put mine on the board flipped compared to those. Most people put the top bearings on the "top" of their picture, whereas mine are the bottoms. Does that explain it?

[Slideways]

That looks like some decent wear. The bottom doesn't look excellent and the top looks close to the end of its life. It's good you changed them. What's weird is most bearings seem to opposite of yours where the bottom is worn and the top looks better. I'm not sure what that's about

You really need to reread your post before posting. The first half of what you said does not match the second half. If the top is "close to the end of its life," then how does the "top look better" as you stated in the second half of your post?

[skristedja]

Here are mine. Done at 124k miles. I thought they were the original bearings, but kaiv noticed some evidence of a previous bearing job when he was in there. They had not been done in my ownership since 2011 at 50k miles and I do not recall or have the previous owner's records on hand to see when the original work was done.

[skristedja]

You really need to reread your post before posting. The first half of what you said does not match the second half. If the top is "close to the end of its life," then how does the "top look better" as you stated in the second half of your post?

Lol, you really need to reread his post before replying to it.

[Slideways]

Lol, you really need to reread his post before replying to it.

He said the bottom looks worse and the top looks better which is not true. Most have the tops worn, not the bottoms.

[JamesSJ1]

He said the bottom looks worse and the top looks better which is not true. Most have the tops worn, not the bottoms.

Hi said the bottoms are "not excellent" which is what I originally said (edited to just say I think they look "good"). He went on to say the tops look end of life, which is a lot worse than "not excellent." Just interpretation. Either way...plenty of copper showing, and I hope this adds to the community knowledge with another another data point comparing Blackstone results and a real look at the condition of the bearings.

[D-O]

I am planning to replace my bearings, along with all the other usual suspects, when she hits 90k (in the next month or so). What about the front crank seal? Anyone replacing that while they are there?

Jesse

[heinzboehmer]

I am planning to replace my bearings, along with all the other usual suspects, when she hits 90k (in the next month or so). What about the front crank seal? Anyone replacing that while they are there?

Jesse

You won't be removing what's needed to access the seal when doing the bearings. Plus, it's pretty easy to get to with the engine all buttoned up, so no need to do it at the same time. Just need to remove belts, crank pulley and harmonic balancer (although I personally removed the whole front end for better access).

[clawhamm3r]

Is anyone doing ARP bolts with a stretch gauge? Seems like a tight fit, curious what gauges are recommended if going the ARP route.
Just curious if that's why everyone just goes OE (besides being OE).