[XutvJet]

Originally Posted by M2driverWV

That's exactly why I went for the LCI. I keep cars long after warranty expires and wrench on everything I own. I knew the N55 would be much cheaper in the long game on ownership with me doing all the work.

I'm in the same boat. I continue to eye ball 2018 M2s though I still love my M235. I'm really not interested in the M2C because like you, I like wrenching on my cars and the S55 is at a different level of complexity and potential expense. Don't get me wrong, the S55 is a gem but it's running costs can be frightening.

[AlpsRider]

Originally Posted by XutvJet

I'm in the same boat. I continue to eye ball 2018 M2s though I still love my M235. I'm really not interested in the M2C because like you, I like wrenching on my cars and the S55 is at a different level of complexity and potential expense. Don't get me wrong, the S55 is a gem but it's running costs can be frightening.

People have been saying that the running costs are so much more for the S55 than the N55. Is that really true or just a projection. Assuming that the 2nd turbo doesn't go out, what real difference in maintenance is there besides the turbo cooling? Apparently it is not that expensive to replace.

[Artemis]

Originally Posted by XutvJet

The N55 in the M2 is the same open deck block as all other N55s. It's plenty strong. The N55 in the M235 and M2 have a stronger forged crank and cylinder oil squiters. All 2014+ N55s use the S55 rod bearings and rods. The M2 N55 has a more race focused oil pan baffle.
Barring some of the earlier pre 2014 N55s with rod bearing issues, the N55 is a pretty dang reliable motor. The motor is generally simple compared to the N54, B58, and S55, easy to work on, and relatively cheap in terms of parts.
The common issues are leaks from the oil filter housing gasket and valve cover gasket and the coolant line from the radiator to expansion tank. Water pump and coil packs will likely need replacement at 70+k mileage.
The N55 in the M2 is a factory pumped up motor and doesn't have the "M" expense. To me, that's perfect for most people. It's plenty powerful and faster and quicker than 99% of the cars on the road.

See chapter 4.1. (Engine N55B30T0) on page 19 and following of the BMW M2 Technical Training 2015 (US version): Attachment 1361382 (72 pages - 2.5 MB).

[Fear-Mongrel]

Originally Posted by XutvJet

The common issues are leaks from the oil filter housing gasket and valve cover gasket and the coolant line from the radiator to expansion tank. Water pump and coil packs will likely need replacement at 70+k mileage.

Which of those issues are as much age-related as mileage related? Asked differently, for those of us who may not be driving as much as expected which of those items will need to be replaced due to age even if the actual mileage on the car is much lower? TIA.

[ZM2]

Originally Posted by XutvJet

The N55 in the M2 is the same open deck block as all other N55s. It's plenty strong. The N55 in the M235 and M2 have a stronger forged crank and cylinder oil squiters. All 2014+ N55s use the S55 rod bearings and rods. The M2 N55 has a more race focused oil pan baffle.

Barring some of the earlier pre 2014 N55s with rod bearing issues, the N55 is a pretty dang reliable motor. The motor is generally simple compared to the N54, B58, and S55, easy to work on, and relatively cheap in terms of parts.

The common issues are leaks from the oil filter housing gasket and valve cover gasket and the coolant line from the radiator to expansion tank. Water pump and coil packs will likely need replacement at 70+k mileage.

The N55 in the M2 is a factory pumped up motor and doesn't have the "M" expense. To me, that's perfect for most people. It's plenty powerful and faster and quicker than 99% of the cars on the road.

These are the reasons why we’re looking getting a used M235i convertible as a fun cruising car (vs M240i), when the M2 beast isn’t required.

[.2pdk]

Originally Posted by KevM2

I was told the same exact thing by my tech! Apparently the seizing here this winter was caused by people driving short distances so there was too much water condensation in the engine oil and it froze solid

So I just spoke to Brent about this and he confirmed this as well.

[ZM2]

Originally Posted by .2pdk

So I just spoke to Brent about this and he confirmed this as well.

If you’re anywhere with extremely cold temps, isn’t this cured by running a 0W oil and changing it once a year?

[.2pdk]

Originally Posted by ZM2

If you’re anywhere with extremely cold temps, isn’t this cured by running a 0W oil and changing it once a year?

Actually he recommended twice to be sure, fall and spring.

Overkill?

Other than that he confirmed the engine is quite good (bullet proof).

[nosbocaj]

Originally Posted by .2pdk

Actually he recommended twice to be sure, fall and spring.

Overkill?

Other than that he confirmed the engine is quite good (bullet proof).

Yeah I just spoke to one of the techs at my local dealership a few days ago when I picked my car up. He said he spends less time on N55 variants than any other engine and the time he does spend on them is usually for minor repairs.

[KevM2]

Originally Posted by ZM2

If you're anywhere with extremely cold temps, isn't this cured by running a 0W oil and changing it once a year?

The 0W oil is great for the cold however, if you're only driving short trips, the amount of water condensation increases because the engine doesn't get a chance to burn off the water. So now you got water mixed in the oil which can freeze and depending on how much water, that can be a huge problem. Not to mention, the amount of fuel mixing with the oil will be higher in winter too so that's another reason to change the oil more frequently in extreme cold.

[.2pdk]

Originally Posted by KevM2

The 0W oil is great for the cold however, if you're only driving short trips, the amount of water condensation increases because the engine doesn't get a chance to burn off the water. So now you got water mixed in the oil which can freeze and depending on how much water, that can be a huge problem. Not to mention, the amount of fuel mixing with the oil will be higher in winter too so that's another reason to change the oil more frequently in extreme cold.

Exactly.

If your leasing to return may not be worth it, holding N55 M2 long term change oil in spring and fall, garage it and when driving it take the long way home.

[Irielion]

M2 lci from 2018. Stage 2 with 450hpmand 655nm. Wagner decat and Eventuri intake. 20.000km.
Hard drive and a lot revving at meetings.

In the beginning some misfires but after changing the sparkling plugs, never any problems again.

[1mm2]

Originally Posted by Irielion

M2 lci from 2018. Stage 2 with 450hpmand 655nm. Wagner decat and Eventuri intake. 20.000km.
Hard drive and a lot revving at meetings.

In the beginning some misfires but after changing the sparkling plugs, never any problems again.

Impressive.

[PilotxERAU]

Originally Posted by PackPride85

If you're buying a German car chances are reliability isn't #1 on your list.

Because Porsche is top 5 in reliability for like 10+ years now.

[F87source]

Originally Posted by .2pdk

Yup, had a 1M up until last year, 35k on it and bulletproof.

It was just that my tech guy at BMW told me this morning he has now seen 3 N55 come in over the last 4 months due to seizing.

Older models, 2011 and 2013 I believe...

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.

[eeyang92]

Originally Posted by AlpsRider

People have been saying that the running costs are so much more for the S55 than the N55. Is that really true or just a projection. Assuming that the 2nd turbo doesn't go out, what real difference in maintenance is there besides the turbo cooling? Apparently it is not that expensive to replace.

Parts (and labor because S).

[MetalMK]

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.

How do you "prime" an oil system? From my understanding, there is still leftover oil on the surface of engine components, you cannot get all the old oil out. And when the new oil is in, there won't be a time where the engine is "running dry".

[F87source]

Originally Posted by MetalMK

How do you "prime" an oil system? From my understanding, there is still leftover oil on the surface of engine components, you cannot get all the old oil out. And when the new oil is in, there won't be a time where the engine is "running dry".

Yeah I asked the same question, but the theory was there would be alot of air bubbles in the flow path of the oil (oil cooler etc) when the OFHG service was done.

There is a whole post about how the priming is done and the method was derived from an official BMW SIB document for the OFHG job, but a quick summary is to unplug the injectors and let the motor crank for 10 seconds 3 times with 20 second breaks in between for the starter to cool.

[akkando]

Originally Posted by eeyang92

Parts (and labor because S).

Maybe. my dealer charges M prices on my n55 m2 because M.

Perhaps an independent shop would be different.

[chris719]

Originally Posted by PilotxERAU

Because Porsche is top 5 in reliability for like 10+ years now.

I don't believe these surveys are necessarily accurate, and I also know from firsthand experience that Porsche has plenty of issues of their own and they will fix them for you (out of warranty goodwill) if you agree to be quiet about it. Porsche is very good at keeping engine failures and things of that nature out of the media now. The 986/996 engine fiasco was pretty well known, but that was a long time ago.

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.

There is no way this is what is happening. There will be a film left, plus the interruption in flow / pressure will be very short. Rod bearing failure is nothing new for BMW but it takes a long time to get to the point where you spin the bearing, seize, and throw a rod. If this were true, we would see tons of regular BMW engines blowing up after every oil change, which just doesn't happen. I fully believe there is a potential rod bearing issue with some of these engines, but not filling the filter housing is not why.

[F87source]

Originally Posted by chris719

I don't believe these surveys are necessarily accurate, and I also know from firsthand experience that Porsche has plenty of issues of their own and they will fix them for you (out of warranty goodwill) if you agree to be quiet about it. Porsche is very good at keeping engine failures and things of that nature out of the media now. The 986/996 engine fiasco was pretty well known, but that was a long time ago.

There is no way this is what is happening. There will be a film left, plus the interruption in flow / pressure will be very short. Rod bearing failure is nothing new for BMW but it takes a long time to get to the point where you spin the bearing, seize, and throw a rod. If this were true, we would see tons of regular BMW engines blowing up after every oil change, which just doesn't happen. I fully believe there is a potential rod bearing issue with some of these engines, but not filling the filter housing is not why.

That was also discussed, everyone has speculated the thin oil film left behind would help save the motor but that hasn't been the case.

Do some research then and you'll see a large number of n55's having locked up engines in particular right after the OFHG replacement. So far it doesn't seem like a coincidence. Also it's not an issue of not filling up the oil filter housing there's also oil coolers and oil cooler lines to consider. And an oil change doesn't empty the oil coolers and all the lines, it only empties the sump which is quickly refilled when you put new oil in, that's the difference.

They believe it could have been caused by a few issues:

1) the OFHG change introduces bubbles into the loop that cannot be purged and these bubbles can interrupt oil flow to the crank.

2) when the gasket fails and is replaced coolant leaks over into the oil side and contaminates the oil tract and ends up degrading the oil. When the car starts it eventually makes it's way to the crank causing it to sieze.

I'm not sure why this is the issue but there have been alot of reports of failure occuring right after these types of services to warranty suspicion. Plus BMW even released an SIB stating to prime the motor after major services to the oil system such as oil cooler swaps, OFHG replacements etc.

[1mm2]

Originally Posted by F87source

I'm not sure why this is the issue but there have been alot of reports of failure occuring right after these types of services to warranty suspicion. Plus BMW even released an SIB stating to prime the motor after major services to the oil system such as oil cooler swaps, OFHG replacements etc.

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?