[Barefoot-335is]

I recently had to replace my oil pan gasket so I had them do the rod bearings while there.
I have a 2012 335is, I'm the second owner, I have changed the oil religiously and the car was Serviced at BMW until 43k miles when I bought it. Car currently had 89k on it when I had them replaced. Car is stock format.
This is what my Rod Bearings looked like at 89k, hadn't failed yet but were on their way.

[Steve Sas]

Hard to see, but that seems to look ok. Usually you would be seeing different layer of material.

[feuer]

Originally Posted by Steve Sas

Hard to see, but that seems to look ok. Usually you would be seeing different layer of material.

NoThat is when they are completely worn. These show scuffs and burnt marks. As said: on their way out.

[Jeef]

if you left those bearings I'm sure you could have still made it to 150k+ miles.

I had a 180k+mile n54 until I decided to be stupid with it..

[feuer]

Originally Posted by Jeef

if you left those bearings I'm sure you could have still made it to 150k+ miles.

I had a 180k+mile n54 until I decided to be stupid with it..

I have rod bearings from n54 that was never tuned with regular maintenance that I replaced the bearings at 150k and will post them here for reference.

[Barefoot-335is]

I am planning on tuning it later this summer and I didn’t want to take the chance.
I use a Good Indy and he did the rod bearings, pan gasket and full DCT service including pulling the trans to get at the top gasket for replacement for $2k
So I’m happy with it and peace of mind is a good thing

[B6T]

I've started pulling the engine but am held up until I can get someone out to evacuate my AC system so I can pull the condenser and compressor out (needed to be replaced anyhow).

The tear down will indicate more of what went wrong; i.e. was it a single bearing that went, or was it multiple. I would think the former would be indicative of a bearing wear issue, the later indicative of an oil starvation issue. The engine sounds like it's only got a single bearing knocking while running so I think it was just a worn bearing.

Look at it this way - there is sufficient evidence to indicate that N54 rod bearings ARE wearing at an unusually fast rate when compared to other popular engines. Are they wearing to the point of total failure? No, but they are wearing excessively, and in most cases not to the point where you'll see engine failures. So these 'fragile' bearings, coupled with higher power output (low RPM torque exceeding 400ftlbs) it shouldn't be a surprise that this happened.

Originally Posted by ragingpanda

Leaking injectors can thin out the oil (poor lubrication) which can then lead spun bearings as well.

Leaking injectors would also lead to hard start and misfires, correct? My car has neither symptom, as well as a fresh oil change at the time of the incident.

[nissubaru]

I had rod bearing failure. I have the pictures somewhere if anyone wants to see, I might have already posted them I can't recall.

I only had one bearing fail, the rest looked perfectly fine.

Edit: Here's my post from when I replaced the bearings out of an 85k mile N54 from an 09 535i. This is the engine I put back into my car, figured I would replace the bearings as well. Cheap insurance and I had the motor on a stand so why not??

https://www.e90post.com/forums/showp...2&postcount=33

[nissubaru]

Here you go, I couldn't find any record of me having posted my photos from the tear down on here.

First two pics are the bearing that spun and the journal with a nice scratch on it. Second set of pics is one of the bearings next to it, maybe I misspoke on "perfectly fine" but it's considerably less fucked up than the one than spun. All of them were like this besides the one that got destroyed. I think it was #4 cylinder







As for your AC evacuation issue, not gonna lie I ran into that problem too and that shit annoyed me so I made the most ghetto blast chamber out of some water bottles and a 2 liter or something, as long as you can get something to press the nozzle you can get it to drain lol. Then just be careful when you crack the lines open when you go to remove the compressor, have rags all around in case some more fluid leaks.

Not my favorite thing to have done but it worked. I had it evacuated and refilled by a shop after I finished the motor swap though. It was just the fact that the car was up on jack stands already and I was doing the swap in my parents garage 30 minutes away so I couldn't just stop and wait for someone to help.

[Saif2018]

Originally Posted by feuer

Oh, that’s relief! I would hate to know what being you is like.

Well I know it must be nuisance to be party pooper like you who makes up assumptions and then continues to argue with people based on assumptions,

Brain malfunction

lol

[feuer]

Originally Posted by Saif2018

Well I know it must be nuisance to be party pooper like you who makes up assumptions and then continues to argue with people based on assumptions,

Brain malfunction

lol

You have you entire life to be gobby and I was really hoping that you will take today off, but no....so sad.

[feuer]

Originally Posted by nissubaru

I had rod bearing failure. I have the pictures somewhere if anyone wants to see, I might have already posted them I can't recall.

I only had one bearing fail, the rest looked perfectly fine.

Edit: Here's my post from when I replaced the bearings out of an 85k mile N54 from an 09 535i. This is the engine I put back into my car, figured I would replace the bearings as well. Cheap insurance and I had the motor on a stand so why not??

https://www.e90post.com/forums/showp...2&postcount=33

They show uneven wear, scuffs and some burn mark. What is your opinion? Do you think was good that you replaced them on an engine with 85k ?

[B6T]

Originally Posted by nissubaru

Here you go, I couldn't find any record of me having posted my photos from the tear down on here.

First two pics are the bearing that spun and the journal with a nice scratch on it. Second set of pics is one of the bearings next to it, maybe I misspoke on "perfectly fine" but it's considerably less fucked up than the one than spun. All of them were like this besides the one that got destroyed. I think it was #4 cylinder

Interesting to see the single bearing failure. I bet my car is the same scenario.

FWIW... my brother used to be a BMW Dealership Tech before moving onto Porsche. He was the engine guy and has rebuilt all sorts of engines, including N54s. He said I might be able to get away with cleaning the journal up and throwing new bearing set in.

However, I found metal debris in my oil filter housing so I just assumed my engine was too far gone to be able to do this and have started to pull the engine, as I've mentioned.

[nissubaru]

Originally Posted by feuer

They show uneven wear, scuffs and some burn mark. What is your opinion? Do you think was good that you replaced them on an engine with 85k ?

As long as I didn't screw anything up during the install, I think it was absolutely worthwhile. I bought a handful of extra rod bolts and I'll admit I had to toss a couple and redo the torquing. For example, one time I felt the engine stand move when torquing it 90 degrees or whatever. I also was having issues keeping the wrench on the rod bolt for some reason, I think it was the flex head portion of my Snap On techangle that was just floppy. Rounded one or two of the rod bolts during the torquing procedure which I tossed and redid.

Not gonna lie you should know what you are doing or be extremely careful when doing it. You should also use a proper calibrated torque wrench. I think I'm 4 or 5k miles post swap now so I think I'm ok but even still I worry sometimes I made a mistake in the torquing step. Absolutely worth it for the peace of mind otherwise

The one thing I will say that I think I said in the other thread, rod bearings are CHEAP compared to a new engine and all the labor that goes into swapping the engine out and the cost of a replacement motor you would be crazy not to do rod bearings during an oil pan gasket job. Given my concerns above even I would consider pulling the pan again and checking the bearings next time I'm down there (upgraded turbos maybe? I went with low mileage used stock turbos during the swap).

I'd like to see some 150k mile bearings for comparison.

[feuer]

Originally Posted by nissubaru

As long as I didn't screw anything up during the install, I think it was absolutely worthwhile.
I'd like to see some 150k mile bearings for comparison.

2010 n54 absolutely not tuned proper maintenance at 150k

[feuer]

2010 n54 75k not tuned probably maintained

[feuer]

2008 n54 tuned properly maintained 115k

[mweisdorfer]

Originally Posted by nissubaru

As long as I didn't screw anything up during the install, I think it was absolutely worthwhile. I bought a handful of extra rod bolts and I'll admit I had to toss a couple and redo the torquing. For example, one time I felt the engine stand move when torquing it 90 degrees or whatever. I also was having issues keeping the wrench on the rod bolt for some reason, I think it was the flex head portion of my Snap On techangle that was just floppy. Rounded one or two of the rod bolts during the torquing procedure which I tossed and redid.

Not gonna lie you should know what you are doing or be extremely careful when doing it. You should also use a proper calibrated torque wrench. I think I'm 4 or 5k miles post swap now so I think I'm ok but even still I worry sometimes I made a mistake in the torquing step. Absolutely worth it for the peace of mind otherwise

The one thing I will say that I think I said in the other thread, rod bearings are CHEAP compared to a new engine and all the labor that goes into swapping the engine out and the cost of a replacement motor you would be crazy not to do rod bearings during an oil pan gasket job. Given my concerns above even I would consider pulling the pan again and checking the bearings next time I'm down there (upgraded turbos maybe? I went with low mileage used stock turbos during the swap).

I'd like to see some 150k mile bearings for comparison.

Would it have been easier to do with ARP bolts? I know they are pricey, but it's my understanding that they are much easier to install vs OEM bolts..

[nissubaru]

Originally Posted by mweisdorfer

Would it have been easier to do with ARP bolts? I know they are pricey, but it's my understanding that they are much easier to install vs OEM bolts..

I don't believe so. When I looked into it the ARP bolts required a stretch measuring gauge tool that ARP sells and its another $170. I'm sure other companies make a gauge tool that can be used but I don't have one. If you are unfamiliar with the tool or stretching bolts you are literally measuring the bolt and the amount that it stretches/lengthens when torqued to spec. Maybe people don't use this tool but I thought it was necessary

[mweisdorfer]

Originally Posted by nissubaru

I don't believe so. When I looked into it the ARP bolts required a stretch measuring gauge tool that ARP sells and its another $170. I'm sure other companies make a gauge tool that can be used but I don't have one. If you are unfamiliar with the tool or stretching bolts you are literally measuring the bolt and the amount that it stretches/lengthens when torqued to spec. Maybe people don't use this tool but I thought it was necessary

The video I saw the guy said all you do is torque them 3x - 10# , then 20# then a final at 36#.

He had a $500-600 digital, snap on torque wrench that measured angles.

Look at this video at 10:20 in

I think that's why the M3 guys almost exclusively use BE ARP bolts so you don't have to use torque to yield or figure out stretch

[autoart]

That video is interesting. I like how he explains how important it is tho keep the engine clean. Then at 15:47 he uses a piece of wood instead of a mallet, and you can clearly see bits of wood go in the engine.

[feuer]

Originally Posted by autoart

That video is interesting. I like how he explains how important it is tho keep the engine clean. Then at 15:47 he uses a piece of wood instead of a mallet, and you can clearly see bits of wood go in the engine.

Absolutely harmless at that point of assembly