Bad S55 week: spun hub, intercooler leak

[SCS55]

Originally Posted by scoale

Good question and I really don't know. Bought used from dealership last week so I'm wondering if it got hooned on a test drive or prior owner. Car was very clean, 22k miles, lease return, and not tuned...but who the heck really knows.

I'll see how things go between now and warranty expiration. At that time, I'll probably opt for extended warranty or upgrade hub and intercooler.

A note on previous owners care, manuals and SCH's...
2016 manual here, several times this year while driving in Efficient and Sport I'll switch to Sport Plus and forget about no rev matching, let the clutch out really fast while down shifting and I get one hell of a deceleration. Enough to feel like I've run into a wall ( me being stupid, lazy and not paying attention).
I'm sure that doesn't help the crank hub at all combined with a money shift. I'm guessing a bunch of those events, unknown previous owners driving history, can all add up to a failure. Possibly the case with your car at only 22K?
I'm going to get mine done if I keep the car.

I hope everything gets sorted out for you

[scoale]

Originally Posted by SCS55

A note on previous owners care, manuals and SCH's...
2016 manual here, several times this year while driving in Efficient and Sport I'll switch to Sport Plus and forget about no rev matching, let the clutch out really fast while down shifting and I get one hell of a deceleration. Enough to feel like I've run into a wall ( me being stupid, lazy and not paying attention).
I'm sure that doesn't help the crank hub at all combined with a money shift. I'm guessing a bunch of those events, unknown previous owners driving history, can all add up to a failure. Possibly the case with your car at only 22K?
I'm going to get mine done if I keep the car.

I hope everything gets sorted out for you

I think you are spot on. In fact, I do not ever drive in Sport Plus because I am afraid I will downshift without rev matching simply because of muscle memory/habit of having rev match in comfort and sport. Someone on the site has posted about this previously (TopJimmy?) , which is what alerted me. I totally agree that this can be a contributor. Honestly, my car looks like previous owner took very good care of it....but that doesn't mean they always flawlessly shifted gears.

I'm definitely going to upgrade crankhub and intercooler when warranty expires.

[aBMWfan]

Originally Posted by scoale

Good question and I really don't know. Bought used from dealership last week so I'm wondering if it got hooned on a test drive or prior owner. Car was very clean, 22k miles, lease return, and not tuned...but who the heck really knows.

I'll see how things go between now and warranty expiration. At that time, I'll probably opt for extended warranty or upgrade hub and intercooler.

I would just do it now if you plan to keep it. Coolant leaking if it happens later, and crankhub slipping later and just replacing that could still leave damage to motor after that. Depends if you keep it long term or only for a short time

[Beemerm3]

That sucks man. Only had it one week! Last time I bought a Mercedes the Steering wheel airbag broke. After a week or two.

[jpy1980]

Originally Posted by scoale

I think you are spot on. In fact, I do not ever drive in Sport Plus because I am afraid I will downshift without rev matching simply because of muscle memory/habit of having rev match in comfort and sport. Someone on the site has posted about this previously (TopJimmy?) , which is what alerted me. I totally agree that this can be a contributor. Honestly, my car looks like previous owner took very good care of it....but that doesn't mean they always flawlessly shifted gears.

I'm definitely going to upgrade crankhub and intercooler when warranty expires.

Better yet, keep driving in S+ and practice heel toeing. I only drive in S+ and it’s really rewarding. You’ll appreciate the car much more!

[scoale]

Originally Posted by jpy1980

Better yet, keep driving in S+ and practice heel toeing. I only drive in S+ and it’s really rewarding. You’ll appreciate the car much more!

I hear you. Been driving manuals many years. I know I am in minority but I actually like the rev match. Better go find my flame suit

[jpy1980]

Originally Posted by scoale

I hear you. Been driving manuals many years. I know I am in minority but I actually like the rev match. Better go find my flame suit

Haha no hate man! It’s an awesome system and truth be told, when I’m on track, pssst, I use it as well. One less thing to worry about when focusing on high speed driving.

But for normal driving, try it out as this car makes it very rewarding when done right more than any other car I had (except my s2000 )

Hope you get your baby back soon and enjoy her!

[Humdizzle]

Originally Posted by SCS55

A note on previous owners care, manuals and SCH's...
2016 manual here, several times this year while driving in Efficient and Sport I'll switch to Sport Plus and forget about no rev matching, let the clutch out really fast while down shifting and I get one hell of a deceleration. Enough to feel like I've run into a wall ( me being stupid, lazy and not paying attention).
I'm sure that doesn't help the crank hub at all combined with a money shift. I'm guessing a bunch of those events, unknown previous owners driving history, can all add up to a failure. Possibly the case with your car at only 22K?
I'm going to get mine done if I keep the car.

I hope everything gets sorted out for you

you can change rev match with a BM3 tune

i turned off rev match in sport because thats what i usually drive in around town. throttle is less touchy than sport plus so you dont buck around in 1st gear over a rough patch of road. plus it forces me to heel toe at all times. even if i switch to my sport+ and forget i'm safe.

turned on rev-match in sport+ because that's maximum attack mode for a back road when i dont want to make a mistake and upset the car's balance.

[TRYM3]

Originally Posted by Beemerm3

Alot of manual m3 are spinning crank hubs.. wonder why.

havent heard a lot of manuals are spinning them, not saying its not possible bc clearly they do but still by far less than dct

[MisterF80M3]

Originally Posted by TRYM3

havent heard a lot of manuals are spinning them, not saying its not possible bc clearly they do but still by far less than dct

I thought that theory has been debunked already. BMW made significantly less manual S55 vs DCT S55.

More people with DCT = more people with DCT spinning their hub

[IB M]

Originally Posted by louielouie

I see others have posted asking for official metrics on this, and while I don't have that, I wanted to add that when I bought my new to me F82 last year and had it coded, the coder mentioned he was seeing way more SCHs in the MY18s than all the prior MYs.

Unproven theory - if MY18 has more SCH issues then it's related to the steel driveshaft being heavier than the MY17 CFRP shaft and creating more rotational torque resistance to engine output during extreme acceleration or deceleration resulting in failure.

[VroomBahpop]

Sorry to hear about your bad fortune and hope all is well in conclusion.

I think Gintani said it best

"If the S55 engine has a weak point, it is the crank hub. BMW have been using this design for years and it has served us well. However, the S55 is a different animal. It revs higher, runs more boost and puts down more power than a tuned N54. Since the crank hub isn'y keyed, it can tend to slip under extreme load, at high revs, or pretty much whenever else it feels like it."

Were playing at the hubs max capabilities, we shouldn't have to baby the hub, 4k is payable just for peace of mind though hopefully will drop in cost soon. Definitely my next step, have a JB4 meth and 10 gallons of juice just sitting around.

Curious what the numbers would be if people actually tried to spin the hub....

[Kilabyte]

Originally Posted by CanAutM3

The intercoolant leaking into the cylinders could have fouled your sparkplugs. The better practice after suffering an intercooler leak is to replace the engine oil and the sparkplugs.

Agreed, that's what I did.

[spuntyb]

Originally Posted by IB M

Unproven theory - if MY18 has more SCH issues then it's related to the steel driveshaft being heavier than the MY17 CFRP shaft and creating more rotational torque resistance to engine output during extreme acceleration or deceleration resulting in failure.

Tough to say this with confidence since the steel driveshafts didn't really start hitting production cars until mid-late in 2018. Plenty of 2018s had the CFRP driveshaft.