[Ozzie335i]

Not disagreeing with this possibility, but how could this explain the high number of failures shortly after OHFG gasket changes?

[Pladi]

Originally Posted by Ozzie335i

Not disagreeing with this possibility, but how could this explain the high number of failures shortly after OHFG gasket changes?

You cant unless you know exactly what causes then to fail in the first place. But blindly replacing rod bearings you have to agree is not a fix of any sorts..

Not saying i would not like them to be replaced but i am more interested in a root cause.

[solo118]

Is it safe to say the higher mileage N55's are "safe"?

I saw the list of failed cars, and they were all what I would call low mileage.

[Ozzie335i]

Originally Posted by Pladi

You cant unless you know exactly what causes then to fail in the first place. But blindly replacing rod bearings you have to agree is not a fix of any sorts..

Exactly why I referred it as a bandaid. With the King bearings I feel that I've got that last bit of clearance so a tad more oil is in there to buy me some time should the hydraulic valve have a temporary hiccup. Or whatever is the cause. I got a new oil pan gasket in the process. I just buttoned up the bottom underneath with one of those cool new skid plates. Of course the new Eibach sway bar was first installed, tying the B12 kit together.

[bbnks2]

Originally Posted by Pladi

Even before i decided to say anything about this valve and we have discussed this possibility before in this forum many times before, i struggle to understand how a 'Normally Open' valve that is in default poaitiin pressed open by a spring can fail. It my be possible that it gets stuck when it has already been actuated. Hard to say.

I guess it would be beneficial to remove and bench test this valve on motors that have seized.

You might not even have to apply and signal since if the theory is correct when you pull them they should be stuck engaged.

Yeah I can't see how this valve plays any kind of role. People having been coming up with these crackpot theories about EVERYTHING with BMW's. Since TIS gives you a part number run date they think that they can just relate failures to any part number change they can find without putting any thought into it or proving it. Just like 2011 BMW's have bad rods, right?

Rod bearing failures are seen in all N5x. N54's and newer N55's as well. How exactly would the issue relate to the electronic valve? The valve BYPASSES oil pressure. If it fails you would just get more pressure not low pressure. Makes 0 sense to blame this valve. The only place I can see it playing any kind of role is being slow to close back up when rpm's drop rapidly causing oil pressure to drop a bit more than it's supposed to. However, there is nothing to substantiate that. Nothing in N55 oil pressure logs look any different than N54 when decelerating and N54's don't have the valve. It's just another baseless theory.

[Ozzie335i]

bbnks2, Pladi was just putting that theory out there. Until BMW comes clean all we have are theories. Likely these rides will all be in junkyards before we have a response. As I had an accident a year ago I still only have 3 or 4 K miles on my new King bearings. Fatty has a lot more. For my money I have a fresh rod bearing set and a new oil pan gasket. All is good for my little 183 cubic inch hot rod.

[frchdragon]

After removing the valve cover, I wasn't impressed by the color of the top end, meaning long oil changes by previous owner.
Comes to mind the rod bearings, I looked on the web and can't seem to find an F30 instruction to change the rod bearing of the N55 engine.

Anyone has a link? Thanks.

[feuer]

Originally Posted by frchdragon

After removing the valve cover, I wasn't impressed by the color of the top end, meaning long oil changes by previous owner.
Comes to mind the rod bearings, I looked on the web and can't seem to find an F30 instruction to change the rod bearing of the N55 engine.

Anyone has a link? Thanks.

Why do you need F30 chassis specific instructions? It’s N55 engine. Follow the instructions for the engine. It’s irrelevant what chassis is mounted in.

[frchdragon]

Originally Posted by feuer

Why do you need F30 chassis specific instructions? It’s N55 engine. Follow the instructions for the engine. It’s irrelevant what chassis is mounted in.

Agreed, but always easier when chassis specific in case subrame of other accessories are different. Such as valve cover gasket replacement, not the same on the X5 and the F30 even though similar engine.

No matter what, i am not a noob and I can figure out what is in the way. But I am have yet to find a walk-through on changing the crankshaft bearing.
Time to get a Bentley manual like in the old days.

[BazIRL]

Had N55 bearings changed bang on 72K miles , routine service intervals at BMW , stock car and there was no premature wear on any of them , failures has to be oil starvation from clogged ports or pick up , way too easy introduce gasket debris into these engines

[DLucian]

Hi everybody,

Was looking over this post and tried to gather as much information as I could. I hope I am not asking what has been discussed, I did read a lot through this thread although not 100% since it is really long. I am looking to do my rod bearings and I still have no idea what would be best way to do this:
- King bearings standard size?
- KOLBENSCHMIDT - one size? - something that I didn't hear about as much but they seem to be an OE Manufacturer for these.
- OE BMW bearings with color matching?

I am really prioritizing a good job here and I am looking for the best way to do this. Car is a standard E91 N55 with BMW power kit and I am not planning on getting any more power since I don't feel these engines are that strong on tunning.

Can anyone shed a little light over what seems to be the best choice, given all this discussion here? Thanks!

[whyzee125]

The issue is absolutely not contamination from changing the OFHG. This happens all the time on N55 but not on N54 or S55 which use the same OFHG. Yes I'm aware that any engine can spin a bearing and plenty of N54's have gone due to a spun bearing but the N55 phenomena is that it's always right after an OFHG job.

There's still no definitive answer as to what causes this, but it's not contamination during the OFHG.

[whyzee125]

Originally Posted by DLucian

Hi everybody,

Was looking over this post and tried to gather as much information as I could. I hope I am not asking what has been discussed, I did read a lot through this thread although not 100% since it is really long. I am looking to do my rod bearings and I still have no idea what would be best way to do this:
- King bearings standard size?
- KOLBENSCHMIDT - one size? - something that I didn't hear about as much but they seem to be an OE Manufacturer for these.
- OE BMW bearings with color matching?

I am really prioritizing a good job here and I am looking for the best way to do this. Car is a standard E91 N55 with BMW power kit and I am not planning on getting any more power since I don't feel these engines are that strong on tunning.

Can anyone shed a little light over what seems to be the best choice, given all this discussion here? Thanks!

Kolbenschmidt makes good bearings and was OE on a lot of older engines like M50's, etc. In this case, I'd probably go either for King or OEM as they're more commonly used so they have more of a track record, though probably any of them will be fine.

I went for King's in my N54 simply because it's what the shop who did it recommended. I believe King splits the difference and makes them all the same size rather than the color coded way like factory. In my head this seems slightly inferior but there are a lot of people running the King bearings, myself included, with no problems at all.

Another school of thought is that running high performance engines slightly looser is the way to go, and if replacing only the rod bearings and not the mains (which is what pretty much anyone would do), looser may be a better match to the already worn in main's. It get a bit complicated and there are few definite answers but the short version is new bearings are better than old ones so go with whatever you like. Either will be just fine.

[DLucian]

Thanks for the reply. I am simply obsessing with doing the best job and I feel that many people and shops go with Kings because of cost and simplicity. Since I am doing this myself and want to rent a workshop with a proper lift, this is also one of my main problems. I can't know the color codes before reading them on the crankshaft and no shop will allow me to buy all the rod bearings and return the unused ones.

L.E. Also, King seems to have 2 types. What they call standard (CR222SV) and racing line (CR222GPC) although I can't seem to find the racing line ones anywhere in stock. Any ideas about these?

[lforter]

Originally Posted by DLucian

Thanks for the reply. I am simply obsessing with doing the best job and I feel that many people and shops go with Kings because of cost and simplicity. Since I am doing this myself and want to rent a workshop with a proper lift, this is also one of my main problems. I can't know the color codes before reading them on the crankshaft and no shop will allow me to buy all the rod bearings and return the unused ones.

L.E. Also, King seems to have 2 types. What they call standard (CR222SV) and racing line (CR222GPC) although I can't seem to find the racing line ones anywhere in stock. Any ideas about these?

I have heard of King having some issues when assembling each pack by sometimes adding a bearing with an incorrect clearance, also vehicular DIY used them and it spun it (although many variables on this equation to know for sure).

I will say that the problem is probably not the bearing itself but rather an oil starvation issue caused by a malfunction in a piece somewhere in the oil system, so doing them won't help much since they are probably going to be in good shape (report if you end up doing them). In my case I went with calico coated king rod bearing since they provide more protection in case of oil starvation.

The racing rod bearing you are describing is probably similar in the sense that it is coated. Should investigate more in the quality of it. Another option is ACL.

[DLucian]

I will be doing them since I plan to keep the car for 4+ years. Will probably go with King and plastigauge everything to make sure my clearances are ok. This should help me avoid potential issues regarding a bad clearance.

Will report back after doing the job but It might take a while since I have to rent a place with a lift to do this.

[335togo]

Originally Posted by hassmaschine

You should preventatively replace the engine too. You know, just in case.

I second that

[DLucian]

Greetings everyone. As intended above, I did a rod bearing job on my E91 335i N55 from 2010 and wanted to share their state for others trying to figure out if this is worth it or not.

I also found a weird plastic thing inside the oil pan. What do you think it could be? It doesn't look broken off if inspected closely, just looks like a very small cap:



So, some info on the car and it's maintenance: E91 335i with N55, first registration at 06.2010, currently at 188.000 km. Full service history at BMW with their more lengthy service interval. The exact oil changes were as such:
1: 06.2012 - 24.500 km
2: 05.2014 - 44.150 km
3: 06.2015 - 69.500 km
4: 05.2016 - 95.800 km
5: 07.2017 - 124.800 km
6: 05.2018 - 140.000 km
7: 05.2019 - 164.000 km
8: 10.2021 - 176.000 km (first oil change done by myself when I bought it)
9: 07.2022 - 188.000 km - rod bearings service

Here is how they look:


What is your take on the state of the bearings given the age and maintenance of the vehicle?

Just to add, I opted for the King bearings. My crankshaft had rrrrrr labeled on it, so full red OE bearings. Tested all clearances with plastigauge and they were just a little over 0.038 and clearly under 0.050. I would have estimated around 0.040 - 0.042. The repair manual stated that they must be under 0.045 for my car. I was surprised just how consistent they were, across all 6 cylinders.

Drove the car around 700 km's since and it drives perfect, so I didn't kill the engine by doing something wrong. Need to check if my new oil pan gasket leaks like the old one.

EDIT: The pictures are not showing, I don't know why. I created an album here: https://ibb.co/album/3y1nP9

[Ozzie335i]

Yeah, they were due for swapping. Do change the oil from now on in shorter intervals. For souped up rides people here are changing the oil every 5 k miles.

[lforter]

Originally Posted by DLucian

Greetings everyone. As intended above, I did a rod bearing job on my E91 335i N55 from 2010 and wanted to share their state for others trying to figure out if this is worth it or not.

I also found a weird plastic thing inside the oil pan. What do you think it could be? It doesn't look broken off if inspected closely, just looks like a very small cap:



So, some info on the car and it's maintenance: E91 335i with N55, first registration at 06.2010, currently at 188.000 km. Full service history at BMW with their more lengthy service interval. The exact oil changes were as such:
1: 06.2012 - 24.500 km
2: 05.2014 - 44.150 km
3: 06.2015 - 69.500 km
4: 05.2016 - 95.800 km
5: 07.2017 - 124.800 km
6: 05.2018 - 140.000 km
7: 05.2019 - 164.000 km
8: 10.2021 - 176.000 km (first oil change done by myself when I bought it)
9: 07.2022 - 188.000 km - rod bearings service

Here is how they look:


What is your take on the state of the bearings given the age and maintenance of the vehicle?

Just to add, I opted for the King bearings. My crankshaft had rrrrrr labeled on it, so full red OE bearings. Tested all clearances with plastigauge and they were just a little over 0.038 and clearly under 0.050. I would have estimated around 0.040 - 0.042. The repair manual stated that they must be under 0.045 for my car. I was surprised just how consistent they were, across all 6 cylinders.

Drove the car around 700 km's since and it drives perfect, so I didn't kill the engine by doing something wrong. Need to check if my new oil pan gasket leaks like the old one.

EDIT: The pictures are not showing, I don't know why. I created an album here: https://ibb.co/album/3y1nP9

The plastic thingy you found is from the VGC, pertaining to the PCV system, I suspect the VCG was done before and the whole plastic stuff broke off...

More info on this thread

https://www.e90post.com/forums/showt...1197637&page=2

[joeyxbender]

Hopefully one of you can help that has had rod bearing failure in past…Others have advised me that my 2013 F30 335j (PWG) has failing rod bearings. It has started making a "metallic rattling" or "metallic vibrating" noise when accelerating lightly from a stop.

Here is a video of me accelerating from a stop where you can clearly hear the vibrating/rattling noise at 2k-3k RPMS:

https://youtube.com/shorts/MeKYDv978a8?feature


PLEASE ADVISE IF YOU CAN HELP.

[fastboatster]

I’m also looking to do the rod bearings on the new to me e90 335i (build date 06/2011) with 109 kmiles. I see that king bearings are backordered everywhere. I don’t really want to use expensive OEMs especially that I don’t yet know which sizes I need to order. Really considering Kolbenschmidt bearings but concerned they might only be good as a replacement for “yellow/red” shell combo. looking to see what other (preferably not to expensive) options are available. Has anyone used ACL race bearings? VAC is also making rod bearings but these are around 500 a set, and I don’t think I need these since I’m not building this engine.