technical N55 rod bearings

Moto_GP

Active member
Firstly, has anyone here experienced a rod bearing failure on the e9X platform?
And secondly, what is the rough cost getting these replaced preventatively?
 

Moto_GP

Active member
I've found an e90 335i with about 100k km that I'm quite fond of. Car is quite clean with a decent service record but doesn't look like bearings have ever been done.

How much of a job would this be?
 

osiris

///Member
If its an N54 E90 335i then rod bearings failures are pretty rare especially at that mileage.
 

Vinnige Fanie

Well-known member
N54/55 Rod bearing failure are popping up more and more now. From what I could find BMW's lifetime on them is 160k km so from a few people I know with cars in that mileage area have been experiencing failures.

I cut open my oil filter and saw some copper flakes and decided to change mine and also add a baffled sump as I do the odd trackday.

With that low mileage it should be fine but it all depends on how often oil was changed and if the car was beat on especially with oil that's not on temp yet.

Price wise I'm a bit full of crap with my cars, So I ordered all new bolts, Gaskets from bmw and got 2 sets of oils so I can flush out assembly lube and left over shavings from the bearings change. But without the baffle it cost me about 12-14k and I did all the labor myself with some mates.

Acl bearings were R3800
Bolts and gaskets R 4277
Oil and filters R 2300
I needed a smaller torque wrench and a few other tools which was about 2000

Pricing I got from a few shops varied from about 10k-20k but then I'm not sure what bearings will be fitted and if they reuse any bolts.
 

osiris

///Member
N54/55 Rod bearing failure are popping up more and more now. From what I could find BMW's lifetime on them is 160k km so from a few people I know with cars in that mileage area have been experiencing failures.

I cut open my oil filter and saw some copper flakes and decided to change mine and also add a baffled sump as I do the odd trackday.

With that low mileage it should be fine but it all depends on how often oil was changed and if the car was beat on especially with oil that's not on temp yet.

Price wise I'm a bit full of crap with my cars, So I ordered all new bolts, Gaskets from bmw and got 2 sets of oils so I can flush out assembly lube and left over shavings from the bearings change. But without the baffle it cost me about 12-14k and I did all the labor myself with some mates.

Acl bearings were R3800
Bolts and gaskets R 4277
Oil and filters R 2300
I needed a smaller torque wrench and a few other tools which was about 2000

Pricing I got from a few shops varied from about 10k-20k but then I'm not sure what bearings will be fitted and if they reuse any bolts.

I think it comes down to how you treat the engine. Like you say allot of people don't let their cars warm up properly, Don't change oil often enough and in my opinion mod for performance before doing proper maintenance, they also push boost through the roof and don't really log or even understand logs to know what the engine is doing so they think the car is running great cause its pushing great numbers on the dyno but in reality the poor motor is pulling massive amounts of timing and slowly but surely getting damaged. It doesn't matter how strong you think an engine is, if it isn't properly maintained or looked after then wear and tear is going to happen much sooner.
 

//M SPORT

Member
On my N55 I'm on 153k odd and this scares me. I treat the car well - don't drive her her much but have the occasional pull... but she is tuned with JB4 and MHD BEF. Power wise she is strong, and she is well maintained - but oil intervals has been slightly over 10k mileage

My concern with changing bearings is the size accuracy of new rod bearings - these can only but put in after measurement else I fear new standard size ones are worse than old worn bearings. Many engine builders don't even bother using plastic gauge and we will never know.

Any recommendations as to who is best with this stuff?

Another thing with N55s is they are notorious for oil starvation after OFHG change - For tis reason, I give my car to a mechanic, showing him the car is perfect before any work is done.
 

osiris

///Member
would be interesting to know what BMW charge as the S motor bearing prices have dropped
I had a interesting little mishap earlier this year where I thought my bearings were toast because I have a carpeted under carriage cover on the Z4, not just plastic like the E9x so when I drained my oil I kept bumping that cover that had lots of bits of sand and dirt in it. when I poured the oil out of the pan I saw all this shiny stuff and thought it was bearing material, I had 7 heart attacks, Once I self revived myself with my car battery I changed oil like honestly it must have been 9 times in the space of a month, to keep checking for stuff and not finding anything! Got quotes from BMW and all over to get bearings done, on the 2nd last oil change within a few days I noticed what was going on when I was crawling under the car and bumped the under tray again and saw a bunch of shit fall into the empty oil pan, so I hit the tray a few times and saw all the tiny stones and bits of sand drop into the oil pan 🤣 and realized why none of this stuff was magnetic and why fokall stuff was in my oil filter.

Anyways The crux of my story is that BMW's quote to do the bearings was an absolute laugh 🤣 I think it was over 100k maybe even more. They refused to do the bearings without changing the crank too which obviously didn't help the quote.

@Peter@AEW would be the guy I was going to use if I did indeed have a bearing issue though. His work on the forum speaks for itself.
 

individj

Well-known member
aaahhh that must of been a relief but also terrible...someone here had their S54 done at SMG Canal Walk for about R16 000 i think.
 
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