[F87source]

Originally Posted by 1mm2

I take it this is far more rare than the crank hub issue in S55 and BMW steps up to the plate in these instances and makes the owner whole?

I don't know if it's more rare since it seems to happen in a wider range of engines (n54, and n55, haven't heard about s55 yet).

I also haven't heard about BMW stepping in either, most owners iirc were left to deal with this on their own. One owner who had an independent shop do it for them had the shop step up.

Yeah this is a really crappy case, but what i'd say is it would be best to try and fill up oil coolers and lines with oil as best as possible, maybe with a syringe along with the oil filter housing before priming to get your best shot at preventing this issue.

Also do what BMW says and drain the coolant before doing this job as well, and also flush the oil cooler loop to prevent oil and coolant cross contamination.

[F87source]

Also another note is that oil cooler outlet position may have an impact oil failures as the E series oil cooler has sideways mounted inlet and outlets while the F series has top and bottom mounted inlet and outlet. Assuming that oil flow is optimal which means in from the bottom and out through the top, air purging should be best on the F series and still very good on the E series. But if you had large bubbles due to unfilled oil lines the E series could have a harder time purging those bubbles.


But it's likely more failures occured on the E series n55 and n54 because they're older cars and have had more OFHG repairs done on it than the newer F series.

[1mm2]

Originally Posted by F87source

I also haven't heard about BMW stepping in either, most owners iirc were left to deal with this on their own. One owner who had an independent shop do it for them had the shop step up.

Even if a BMW dealer does the work on the OFHG?

[TemjinX2]

Originally Posted by F87source

I believe the issue is caused by changing oil filter housings and not having the oil system primed before starting causing there to be a period of time where the engine is "running dry" of oil. This causes the crank to become seized to the bearings and it can even snap according to posts on a different forum.

I doubt its from oil priming...I diy the OFHG on my n54 which is in the same location as the n55 without priming the oil. Drove my n54 on a stage 1 tune without any issues for 3yrs.

the early E n55s had rod bearing issues, keep in mind the first n55s was BMWs way of trying to make a cheaper n54. I suspect its one of the reasons BMW upgraded the N55 rods and bearings in the later F series N55s.

[F87source]

Originally Posted by 1mm2

Even if a BMW dealer does the work on the OFHG?

It happens on higher mileage and older cars which are out of warranty, so most people do it themselves or have aftermarket shops do it. Another reason why we don't see many dealer failures could be attributed to them having SIB access and knowing to prime the loop, or that they will cover the issue if one does arise. If the dealer covers the issue people will be less likely to complain and that's why you don't hear much about it.

Originally Posted by TemjinX2

I doubt its from oil priming...I diy the OFHG on my n54 which is in the same location as the n55 without priming the oil. Drove my n54 on a stage 1 tune without any issues for 3yrs.

the early E n55s had rod bearing issues, keep in mind the first n55s was BMWs way of trying to make a cheaper n54. I suspect its one of the reasons BMW upgraded the N55 rods and bearings in the later F series N55s.

Maybe that could be the case, but the issue happened on the n54 as well so it may not be bearing attributed.

Imo it's either priming or coolant contamination.

[1mm2]

Originally Posted by F87source

It happens on higher mileage and older cars which are out of warranty, so most people do it themselves or have aftermarket shops do it. Another reason why we don't see many dealer failures could be attributed to them having SIB access and knowing to prime the loop, or that they will cover the issue if one does arise. If the dealer covers the issue people will be less likely to complain and that's why you don't hear much about it.

Got it, thanks.

[TemjinX2]

Originally Posted by F87source

It happens on higher mileage and older cars which are out of warranty, so most people do it themselves or have aftermarket shops do it. Another reason why we don't see many dealer failures could be attributed to them having SIB access and knowing to prime the loop, or that they will cover the issue if one does arise. If the dealer covers the issue people will be less likely to complain and that's why you don't hear much about it.


Maybe that could be the case, but the issue happened on the n54 as well so it may not be bearing attributed.

Imo it's either priming or coolant contamination.

the n54 rod bearings were usually from leaky injectors leaving gasoline in the cylinders and diluting the oil since the gasoline acts as a solvent.

you can kinda get away from it if you daily drive your car but if you didn't drive often the oil becomes diluted enough where you can spun a bearing or if you didn't replace the leaky injectors in time.

other cases of bearing or rod failure in the n54 i've seen are mostly ppl going 650whp+ on a stock block.

one guy threw a rod on a n54, but he was 836whp on a stock block racing mcclarens half mile racing.


I was little hesitant on the n55 m2...on the E-series forums if the N54 is Thor, the n55 is considered the loki of BMW engines. I had more confidence after reading the improvements BMW made with the pistons, rods and rod bearings with the M2 N55.

[F87source]

Originally Posted by TemjinX2

the n54 rod bearings were usually from leaky injectors leaving gasoline in the cylinders and diluting the oil since the gasoline acts as a solvent.

you can kinda get away from it if you daily drive your car but if you didn't drive often the oil becomes diluted enough where you can spun a bearing or if you didn't replace the leaky injectors in time.

other cases of bearing or rod failure in the n54 i've seen are mostly ppl going 650whp+ on a stock block.

one guy threw a rod on a n54, but he was 836whp on a stock block racing mcclarens half mile racing.


I was little hesitant on the n55 m2...on the E-series forums if the N54 is Thor, the n55 is considered the loki of BMW engines. I had more confidence after reading the improvements BMW made with the pistons, rods and rod bearings with the M2 N55.

No I meant the cases of siezing crank shafts.

[TemjinX2]

Originally Posted by F87source

No I meant the cases of siezing crank shafts.

ah ok...got it.

[gandapanda]

Originally Posted by TemjinX2

I was little hesitant on the n55 m2...on the E-series forums if the N54 is Thor, the n55 is considered the loki of BMW engines. I had more confidence after reading the improvements BMW made with the pistons, rods and rod bearings with the M2 N55.

Hang on, are you telling me that the N55 has the dependability of Loki as well?

[TemjinX2]

Originally Posted by gandapanda

Hang on, are you telling me that the N55 has the dependability of Loki as well?

i would say the popularity and strength of loki lol. the e series n55 wasnt that great other then the fact bmw fixed the injector issues and mostly fixed the HPFP issues.

the early n55s are becoming more popular now since they have big single turbo kits for them now and the cars are dirt cheap.

[TMR013]

Good thread. Coming from an N54 135, I can remember that by this time in the life cycle there were plenty of issues, HPFP, vanos, water pump failure, waste gate rattle, valve carbon build up... But I have not seen any of that, at least on the M2 forum. I hope that means they addressed those issues on the N55.
I still wonder if the walnut blast will be needed when it gets a few 10K miles more down the line. The engine I believe still has direct fuel injection. Anybody gotten far enough down the line to look at the valve covers?

[Irielion]

Originally Posted by 1mm2

Impressive.

This is how it sounds!

[Sungillest]

Love my N55b OG M2 !

With MPE, sounds awesome!

[GoneIn4Secs]

What does idle revving do and why is it so bad?

[///M TOWN]

Originally Posted by .2pdk

Nope...N55 he was very specific.

OGM2 has a better version of the standard issue N55

[Sungillest]

Originally Posted by ///M TOWN

OGM2 has a better version of the standard issue N55

Yup! Correct! N55b is totally different. Same layout as N55 but internal materials different stronger/ better in general.

[EDWYER]

Originally Posted by .2pdk

Just curious about the N55 reliability in the M2 so far.

My N55 M2 has 80k and is running strong.