[1mm2]

Before I start please don't flame me as I am unfortunately afflicted with the "paranoia" gene.

A little background first, I'm coming from a 1M and currently drive a 128, bought the wife an M2 (2018 LCI) and love it. As we use these cars as daily drivers I'm contemplating buying either a 2018 LCI or M2C to replace the 128 for myself (no kids, have done the 911s and for my use simply not cost effective).

My research indicates the OG M2 is quite reliable overall.

I would like opinions on the reliability of the S55 with respect to spun crank hub and risks of the oil cooler location.

Both of the above kinda bother me so looking for owner experience with any of these two potential problems.

Thanks in advance and please be gentle.

[MazdaPower]

Originally Posted by 1mm2

with respect to spun crank hub

Statistically unlikely

Originally Posted by 1mm2

risks of the oil cooler location

Elevated.

[DanG]

You would be better asking this question in the M3/M4 forum. They have much more experience with the S55 engine.

[Thescout13]

Originally Posted by MazdaPower

Statistically unlikely

Elevated.

This.

[heavyD^2]

It does appear that there's a slight reliability tradeoff to be paid for the extra power of the S55. Does seem that there's been more than a few failures and it's simply more complex overall with the oil cooler location as well as the liquid to air intercooler. Nothing alarming or widespread but the N55 stock is pretty reliable which is why the M2 has a solid reputation for reliability.

[aerokubectl]

Originally Posted by MazdaPower

Statistically unlikely


Elevated.

This

[1mm2]

Originally Posted by heavyD^2

It does appear that there's a slight reliability tradeoff to be paid for the extra power of the S55. Does seem that there's been more than a few failures and it's simply more complex overall with the oil cooler location as well as the liquid to air intercooler. Nothing alarming or widespread but the N55 stock is pretty reliable which is why the M2 has a solid reputation for reliability.

Originally Posted by spetsnazos

This

Thanks to all for your responses.

I will test drive an M2C again (more extensively) and then hop back into my wife's to decide if the extra performance (for my needs) is worth the extra coin and potential reliability risks (even though they sound low).

[N8shon]

In the same boat here-trying to make the right decision for my next daily M car.

[waldrops]

If you don't plan on voiding your warranty via DP/Tune, I don't see why it matters. Warranty covers it all

[Thescout13]

Originally Posted by waldrops

If you don't plan on voiding your warranty via DP/Tune, I don't see why it matters. Warranty covers it all

Until it doesn't, because you know, it expires...?

[M1Curious]

Originally Posted by 1mm2

Before I start please don't flame me as I am unfortunately afflicted with the "paranoia" gene.

A little background first, I'm coming from a 1M and currently drive a 128, bought the wife an M2 (2018 LCI) and love it. As we use these cars as daily drivers I'm contemplating buying either a 2018 LCI or M2C to replace the 128 for myself (no kids, have done the 911s and for my use simply not cost effective).

My research indicates the OG M2 is quite reliable overall.

I would like opinions on the reliability of the S55 with respect to spun crank hub and risks of the oil cooler location.

Both of the above kinda bother me so looking for owner experience with any of these two potential problems.

Thanks in advance and please be gentle.

Originally Posted by 1mm2

Before I start please don't flame me as I am unfortunately afflicted with the "paranoia" gene.

A little background first, I'm coming from a 1M and currently drive a 128, bought the wife an M2 (2018 LCI) and love it. As we use these cars as daily drivers I'm contemplating buying either a 2018 LCI or M2C to replace the 128 for myself (no kids, have done the 911s and for my use simply not cost effective).

My research indicates the OG M2 is quite reliable overall.

I would like opinions on the reliability of the S55 with respect to spun crank hub and risks of the oil cooler location.

Both of the above kinda bother me so looking for owner experience with any of these two potential problems.

Thanks in advance and please be gentle.

oil cooler problem has an aftermarket solution. there is a metal replacement cage instead of the oem plastic. get that to ease your mind, or try not to hit large rocks .

spun crank hub has an aftermarket solution as well. but like others have pointed out, its unlikely to happen on a stock setup, and if it does it will most likely happen during your warranty period and warranty covers it. you are still statistically unlikely to experience this though. of all the problems being reported for the M2C I've experienced none of them @ 8k miles of driving it.

Hope that helps!

[1mm2]

Originally Posted by waldrops

If you don't plan on voiding your warranty via DP/Tune, I don't see why it matters. Warranty covers it all

Originally Posted by Thescout13

Until it doesn't, because you know, it expires...?

I understand warranty covers most but I don't believe it covers oil cooler puncture. That's when insurance battles it out with BMW if engine needs rebuild/replacement.

Then of course there's the "after warranty" issue if you plan on keeping long term.

[1mm2]

Originally Posted by M1Curious

oil cooler problem has an aftermarket solution. there is a metal replacement cage instead of the oem plastic. get that to ease your mind, or try not to hit large rocks .

spun crank hub has an aftermarket solution as well. but like others have pointed out, its unlikely to happen on a stock setup, and if it does it will most likely happen during your warranty period and warranty covers it. you are still statistically unlikely to experience this though. of all the problems being reported for the M2C I've experienced none of them @ 8k miles of driving it.

Hope that helps!

Thanks.

The IND after market cage is better than stock but will not stop small rocks at speed puncturing the cooler which is beyond delicate.

I wonder how many have gotten the aftermarket cage...

[M1Curious]

Originally Posted by 1mm2

Thanks.

The IND after market cage is better than stock but will not stop small rocks at speed puncturing the cooler which is beyond delicate.

I wonder how many have gotten the aftermarket cage...

Originally Posted by 1mm2

Thanks.

The IND after market cage is better than stock but will not stop small rocks at speed puncturing the cooler which is beyond delicate.

I wonder how many have gotten the aftermarket cage...

good question. I'm more worried about the bigger rocks tbh. Ive driven over some shabby rocky county roads at speed and have never had issues. only person ive seen personally affected by the low oil cooler hit a rock about the size of a softball and it lodged between the road and his oil cooler. for what its worth.

[Thescout13]

Originally Posted by 1mm2

I understand warranty covers most but I don't believe it covers oil cooler puncture. That's when insurance battles it out with BMW if engine needs rebuild/replacement.

Then of course there's the "after warranty" issue if you plan on keeping long term.

Oil cooler puncture is really rare and easy and cheap to prevent.

[TemjinX2]

some s55 owners had near scares with hydro lock with leakying intercoolers. the fix is to get a csf intercooler. leaky air to air system...you just loose boost.



n55 is similar to that old GM joke where BMW made the n55 engine for so long that its reliable.

the n55 is bit more reliable with the air to air system versus the air to water system of the s55. air to water systems are more efficient but more things can go wrong and air to air systems recover from heat soak more quickly.

also keep in mind the n55 was mass produced so maintence parts will probably be cheaper and more plentiful

i was in a similar sitiuation as you...i decided to get a lightly used OG M2 with only 5k miles for 43k because i was ok with the lower power and i thought it was a simplier more reliable system at a cheaper price.

i was ok with the power of just FBO....if you want 1000whp i would go with the s55...its a better platform to start off with for that goal.

[chris719]

Originally Posted by TemjinX2

some s55 owners had near scares with hydro lock with leakying intercoolers. the fix is to get a csf intercooler. leaky air to air system...you just loose boost.



n55 is similar to that old GM joke where BMW made the n55 engine for so long that its reliable.

the n55 is bit more reliable with the air to air system versus the air to water system of the s55. air to water systems are more efficient but more things can go wrong and air to air systems recover from heat soak more quickly.

also keep in mind the n55 was mass produced so maintence parts will probably be cheaper and more plentiful

i was in a similar sitiuation as you...i decided to get a lightly used OG M2 with only 5k miles for 43k because i was ok with the lower power and i thought it was a simplier more reliable system at a cheaper price.

i was ok with the power of just FBO....if you want 1000whp i would go with the s55...its a better platform to start off with for that goal.

Yes, I think it is safe to say that N55 is much more reliable than S55. There are not that many reports of N55 failures when you think about the fact that it's been in basically every vehicle BMW makes. S55 is only in 3 lower volume models and there seem to be more reports of issues. Obviously, S55 is still a better performer.

[akkando]

Originally Posted by TemjinX2

some s55 owners had near scares with hydro lock with leakying intercoolers. the fix is to get a csf intercooler. leaky air to air system...you just loose boost.



n55 is similar to that old GM joke where BMW made the n55 engine for so long that its reliable.

the n55 is bit more reliable with the air to air system versus the air to water system of the s55. air to water systems are more efficient but more things can go wrong and air to air systems recover from heat soak more quickly.

also keep in mind the n55 was mass produced so maintence parts will probably be cheaper and more plentiful

i was in a similar sitiuation as you...i decided to get a lightly used OG M2 with only 5k miles for 43k because i was ok with the lower power and i thought it was a simplier more reliable system at a cheaper price.

i was ok with the power of just FBO....if you want 1000whp i would go with the s55...its a better platform to start off with for that goal.

The weak point of the n55 m2 is really the cooling. That's really the one thing that makes the s55 really stand out as an upgrade to me is you can beat on the s55 and it just stays cool, at least at stock tune. Upgrade that one thing and it might not seen so far away from the m2c in terms of experience.

There are other nice upgrades with the m2c, but I feel the cooling is the big one as I feel the n55 m2 on a spirited drive to just feel the power disappear rather quickly as the car heats up.


As far as reliability I think the s55 is good when it comes to S designated M engines. The n55 in the m2 even better, but obviously it's less advanced in a number of ways.

[TemjinX2]

Originally Posted by akkando

The weak point of the n55 m2 is really the cooling. That's really the one thing that makes the s55 really stand out as an upgrade to me is you can beat on the s55 and it just stays cool, at least at stock tune. Upgrade that one thing and it might not seen so far away from the m2c in terms of experience.

There are other nice upgrades with the m2c, but I feel the cooling is the big one as I feel the n55 m2 on a spirited drive to just feel the power disappear rather quickly as the car heats up.


As far as reliability I think the s55 is good when it comes to S designated M engines. The n55 in the m2 even better, but obviously it's less advanced in a number of ways.

s55 has better cooling since its a air to water system. for general driving...air to water systems are more efficient then air to air. Its when you start doing back to back pulls or really long track seccessions is when you start to see the weaknesses in air to water systems.

you can buy bigger heat exchangers or add more pumps but it starts getting expensive really fast compared to just buying a bigger FMIC in a air to air system. its one of the reasons why most of the 2000whp-3000whp cars you see in half mile racing are air to air systems, also the quicker heat soak recovery.

my canyon runs are at 11k ft elev...i've boiled coolant in air to water systems just from canyon runs due to high heat and low air density.

[1mm2]

Originally Posted by akkando

There are other nice upgrades with the m2c, but I feel the cooling is the big one as I feel the n55 m2 on a spirited drive to just feel the power disappear rather quickly as the car heats up.

Really? I've taken my wife's out repeatedly for extensive "spirited" drives and never felt power quickly disappear...

[akkando]

Originally Posted by 1mm2

Really? I've taken my wife's out repeatedly for extensive "spirited" drives and never felt power quickly disappear...

Yea that's my experience.

[1mm2]

Originally Posted by akkando

Yea that's my experience.

I'll have to try harder next time...