[iqraceworks]

Originally Posted by lordbmw

I had a spun bearing.

No clue why.
Happened a month ago.
I was not the original owner of the car so no clue what he/she did.
May be they drove it like they stole it stone cold.

How many N54's have you heard of that have spun a bearing? It's pretty darn rare. I'd say that it's probably very strongly related to how well they have been taken care of. Some people think 15K between oil changes is fine........

If I'm going to go to the trouble of replace rod bearings.....I'd might as well pull the motor and replace the crank bearings too. And then do the main seals...etc, etc....

[Cabdriver]

Originally Posted by iqraceworks

How many N54's have you heard of that have spun a bearing? It's pretty darn rare. I'd say that it's probably very strongly related to how well they have been taken care of. Some people think 15K between oil changes is fine........

If I'm going to go to the trouble of replace rod bearings.....I'd might as well pull the motor and replace the crank bearings too. And then do the main seals...etc, etc....

Yeah i agree, if the rod bearings are bad it didnt stop there.

[Jeef]

Originally Posted by feuer

is a moving part, so yes, wear item, just like a tire

Sorry I should have been more clear. People are making it sound like a maintenance item.

there are a lot of moving parts... lol

[nissubaru]

Originally Posted by iqraceworks

How many N54's have you heard of that have spun a bearing? It's pretty darn rare. I'd say that it's probably very strongly related to how well they have been taken care of. Some people think 15K between oil changes is fine........

If I'm going to go to the trouble of replace rod bearings.....I'd might as well pull the motor and replace the crank bearings too. And then do the main seals...etc, etc....

I also have an N54 that spun a bearing...just because you haven't heard of it doesn't mean it doesn't happen. There was a guy on here not long ago who picked up a 335is with like 65k miles on it and it developed rod knock within a couple weeks/days of his purchase.

Your logic of pulling the entire engine to also replace the main bearings is also flawed. The rod bearings are literally right there after you've removed everything to get down to the oil pan. There are only a couple more things in the way, the sprocket holding the chain to the oil pump, the pickup tube, and the windage tray.

Excuse the photo below, it's the best I could find on the internet but the windage tray bolts are shown. Same with the pickup tube bolts, remove them and pull the tube out of the oil pump. There's an o-ring that should be replaced as well.



Here's the oil pump bolt, reinstalling was slightly "tricky" as you have to wedge something in between the sprocket and pump to tighten it without turning the gear.




For the $150 or so that it costs to replace the bearings I would do it again in a heartbeat. Replacing my motor sucked balls, finding a decent engine that I was comfortable paying $3000 for and then installing was a nightmare. I spent countless hours on the phone calling junkyards all over the country, literally anywhere in the country that had an N54 with less than like 85k miles I called them. 99.9% of places couldn't or wouldn't do a compression or a leakdown test, the majority of the places provide no warranty on the motor and then even if you think you found a good motor out of a low mileage car..who knows if it's even from the same car. I was this close to buying a low mileage engine with like 45k miles on the clock for a decent price nearby, but then I bought the CarFax for the vehicle and found out the car had like 85k miles on it instead. Called the junkyard back up and called them out on it and they acted like they had no clue.

So now you've spent ~$3000 on a motor and you still have to get it swapped in, if you have to swap over turbos then it's what another $200 or so for the install kit. Not to mention any other items you want to replace while you're in there such as rear main seal, vcg, ofhg etc...oh, and since I probably got metal flakes in the oil cooler I had to replace the cooler and lines too, another $150.

It's your choice, but I would err on the side of caution. Heck even if you just pulled the bearings to check them I would be happy. It's a few hours now that could save you days/weeks in the future.

[feuer]

Originally Posted by nissubaru

I also have an N54 that spun a bearing...just because you haven't heard of it doesn't mean it doesn't happen. There was a guy on here not long ago who picked up a 335is with like 65k miles on it and it developed rod knock within a couple weeks/days of his purchase.

I assume issue was existing at time of purchase and probably noticed by new customer right after the first oil change when what over was put in the engine to mask the knock got flushed.

[nissubaru]

Originally Posted by feuer

I assume issue was existing at time of purchase and probably noticed by new customer right after the first oil change when what over was put in the engine to mask the knock got flushed.

Idk if you recall the thread or not but pretty much that. Oil was changed and then the issue popped up within the next 500 miles

https://www.e90post.com/forums/showthread.php?t=1653591

[feuer]

Originally Posted by nissubaru

Idk if you recall the thread or not but pretty much that. Oil was changed and then the issue popped up within the next 500 miles

https://www.e90post.com/forums/showthread.php?t=1653591

I don't know about the OFHG Those are being replaced in thousands ever day through out the world with out issue.

[iqraceworks]

I'm just saying that if your rod bearings are shot.....or severely worn, there is a good chance that the crank bearings are worn also. Why would you do one and not the other?

I guess when it's all said and done....do what you want.

[nissubaru]

Originally Posted by iqraceworks

I'm just saying that if your rod bearings are shot.....or severely worn, there is a good chance that the crank bearings are worn also. Why would you do one and not the other?

I guess when it's all said and done....do what you want.

Right cause all of the M3 guys disassemble their motors and replace the main bearings as well. Nope the majority of them just do the rod bearings because those are typically what fails.

You're arguing that failed rod bearings = failed crank bearings which is rarely the case. And then you're arguing that if you're going to spend the extra 4 hours replacing the rod bearings that you should pull the motor and essentially rebuild it because that's what it will take to remove and replace the main bearings.

Did you just get your N54 for $5k or something?

[IllSic_Design]

Originally Posted by nissubaru

Did you just get your N54 for $5k or something?

Pretty sure he did not too long ago lol, nothing against you Iq.


And yeah as said, an oil analysis doesn't always work for these cars to tell how the bearings are doing. As we have been shown by Feuer(and others on this forum), you can have good oil analysis' and then bam a bearing starts making noise.

[TheMidnightNarwhal]

Originally Posted by feuer

I don't know about the OFHG Those are being replaced in thousands ever day through out the world with out issue.

Ehh idk man, it's still weird for it to happen shortly after that job, even from BMW techs I read stories about it.

[Ozzie335i]

Originally Posted by iqraceworks

I'm just saying that if your rod bearings are shot.....or severely worn, there is a good chance that the crank bearings are worn also. Why would you do one and not the other?

I guess when it's all said and done....do what you want.

When those of us, myself included, have provided photos of the bearings that we replaced the upper rod bearings pretty much always showed more wear than the lower. With that info surely you can deduce why, and why the mains don't have similar wear. The mains typically are affected when a spun rod bearing had partially disintegrated.

As far as few N54 rod bearing issues goes, most were attributed to leaky injectors. Could it be that there aren't many now since the newer, better functioning injectors have aleviated that problem a few years back. BTW, in the DFW area I have noticed less and less e92 335s with either engine.

[IllSic_Design]

Originally Posted by TheMidnightNarwhal

Ehh idk man, it's still weird for it to happen shortly after that job, even from BMW techs I read stories about it.

I have done 6+ N54 OFHG and never had/heard of any issue from any of them.

[TheMidnightNarwhal]

Originally Posted by IllSic_Design

I have done 6+ N54 OFHG and never had/heard of any issue from any of them.

I haven't heard anything on instant failure after on N54 it's just N55.

[IllSic_Design]

Originally Posted by TheMidnightNarwhal

I haven't heard anything on instant failure after on N54 it's just N55.

oh yeah, I though that's what was being discussed since the thread is about N54's. Nevermind......

[iqraceworks]

Originally Posted by nissubaru

Right cause all of the M3 guys disassemble their motors and replace the main bearings as well. Nope the majority of them just do the rod bearings because those are typically what fails.

You're arguing that failed rod bearings = failed crank bearings which is rarely the case. And then you're arguing that if you're going to spend the extra 4 hours replacing the rod bearings that you should pull the motor and essentially rebuild it because that's what it will take to remove and replace the main bearings.

Did you just get your N54 for $5k or something?

Nope.....$3,500 😜. And I'm not going to touch the rod bearings.

[miksebik]

Well, I did the rod bearing change as i preventative measure on my N54 when it had 100k miles. And I am glad I did it. The bearings were slightly scored, the crank too. I posted some info about it on the other forum with N54 in its name. I am not sure if I can post a link here.
Sure, somebody might have treated it badly before me.. But at least now I know, this part is OK. I did all the bushings on subframes with it too.

[miksebik]

Just trying if it goes through...

https://www.n54tech.com/forums/showthread.php?t=51562

[AngelFarelli]

Need to do my oil pan and oil pan gasket as well and am wondering if I should replace my rod bearings and bolts on my 140k mile n55 ?

[feuer]

Originally Posted by AngelFarelli

Need to do my oil pan and oil pan gasket as well and am wondering if I should replace my rod bearings and bolts on my 140k mile n55 ?

If you are enough mechanically inclined and have the tools do it.

[Knerr]

Originally Posted by mweisdorfer

Idk.

Rod bearings is an e90 M3 issue not an n54 issue.

Maybe if you are going over 600HP, then put some better, after mkt rod bearings on for preventative maintenance so you can sleep better at night.

However, the motor will be out of balance in terms of new parts on the bottom & not at the top. It's almost as if you you should do a valve job up top. IDK if this makes sense. Just thinking out loud.

Idk. You rarely here about rod bearings going bad on an N54. It's about as rare as the head gasket going bad on an N54.

Either I am the most unlucky N54 owner of all time, or these things are severely underreported.

I have had BOTH a spun rod bearing and a blown head gasket on two seperapte N54 cars, and no, they were not clapped out $5000 cars.

Attached is my beloved head gasket blower, currently under the knife for a full rebuild and new turbos.

[mweisdorfer]

Originally Posted by Knerr

Either I am the most unlucky N54 owner of all time, or these things are severely underreported.

I have had BOTH a spun rod bearing and a blown head gasket on two seperapte N54 cars, and no, they were not clapped out $5000 cars.

Attached is my beloved head gasket blower, currently under the knife for a full rebuild and new turbos.

Are you tracking it? How much HP?