[fastbul]

Hi all

New member here. I bought a CS a few weeks ago and quickly realised water was leaking in to the passenger footwell. I took the car in to a dealer last week and they tell me the roof is becoming un-stuck (I can’t think of a better way of saying the roof is coming off). It’s now going back to BMW uk for a replacement roof. Has anyone else had this problem.

Thanks
Tony

[ShaknBak]

Ouch, sorry to hear this is your initial experience as a M2CS owner.

I think I only recall seeing one other roof replacement in the forum and I don’t think that one was leaking, just delaminating?

[windnsea00]

Wow, never heard of this granted I never drive my car in the rain. I bet BMW will take care of you.

[///MPhatic]

So sad for a flagship car. But to be honest, BMW have always had issues with their carbon roofs, to the point to where I wouldn't buy one of the cars that have them.

[M3R1]

Originally Posted by ///MPhatic

So sad for a flagship car. But to be honest, BMW have always had issues with their carbon roofs, to the point to where I wouldn't buy one of the cars that have them.

Ironically, the one thing that bothered me about my M3, was that it did not have a carbon roof... I honestly would have kept the car...

[///MPhatic]

Originally Posted by M3R1

Ironically, the one thing that bothered me about my M3, was that it did not have a carbon roof... I honestly would have kept the car...

Just quit. I miss your M3 and it wasn't even mine!

The ladies we part with in order to get what we think we need. I want them all back.

[M3R1]

Originally Posted by ///MPhatic

Just quit. I miss your M3 and it wasn't even mine!

The ladies we part with in order to get what we think we need. I want them all back.

Seriously! I wish I could as well! At least some of them..

[bruiser135msport]

Originally Posted by ///MPhatic

So sad for a flagship car. But to be honest, BMW have always had issues with their carbon roofs, to the point to where I wouldn't buy one of the cars that have them.

That’s a very gross exaggeration of the facts :

With over a 2000+ world-wide production figure for the BMW M2 Cs and only one or two known failures that’s a pretty small figure for a failure rate of the Carbon Fibre Roof .

This one makes 2 : when I did mathematics at school and in my job that’s a pretty (very) small percentage .

In the aerospace industry we would accept that failure rate hands down as a consequence of hi-technology production and possible production flaws .

No one is denying there have been problems but your statement is incorrect !

For the Op : There has been some delaminated roofs but never ever a water leak from the Carbon Fibre roof until now .

Just for your information in one of the harshest climates in the world their has not been one failure rate of Cs Carbon Fibre Roofs here in Australia .

It’s your choice to miss out on one of the most iconic modern bmw’s .

Cheers
Bruce

[///MPhatic]

Originally Posted by bruiser135msport

That’s a very gross exaggeration of the facts : With over a 2000+ world-wide production figure for the BMW M2 Cs and only one or two known failures that’s a pretty small figure for a failure rate of the Carbon Fibre Roof .

Yours is the gross exaggeration, many of these roofs have issues, if not leaks, and have had for years.

Originally Posted by bruiser135msport

In the aerospace industry we would accept that failure rate hands down as a consequence of hi-technology production and possible production flaws .

This isn't the aerospace industry, this is the car industry, and if you can't do it right, don't do it (especially for a part that is AESTHETIC ONLY).

Originally Posted by bruiser135msport

It’s your choice to miss out on one of the most iconic modern bmw’s .

Cheers
Bruce

The CS is no more iconic than the OG. In fact, I'd argue the contrary.

[ThreeStripes]

Originally Posted by ///MPhatic

The CS is no more iconic than the OG. In fact, I'd argue the contrary.

So F dumb.

[Davil]

[QUOTE=bruiser135msport;30609220]
Just for your information in one of the harshest climates in the world their has not been one failure rate of Cs Carbon Fibre Roofs here in Australia .


I’ve been in sustained torrential rain to the level you would never encounter in the UK. No problems at all. Weirdly enough my cup 2s also coped, though forum posters will tell you that’s not possible. File along with seat height and camber, steering feel etc.

I seem to recall reading about the passenger footwell water problem with other M2s though. So maybe it’s not the roof?

[chris719]

Originally Posted by Davil

I seem to recall reading about the passenger footwell water problem with other M2s though. So maybe it’s not the roof?

Yes, this is quite possible. Unfortunately it may be that the roof is also delaminating or detaching and the dealer is troubleshooting it incorrectly because of that.

[Beenz]

OP- welcome and sorry to hear about your leak. My 2c:
1. Only pay close attention to posts from actual CS owners. The rest is mostly noise, and largely misguided.

2. That is a highly unusual issue you have and certainly not any currently known fault in a CS roof. As the car should still be in warranty let BMW sort it out. Although I do share scepticism about it being a roof leak, that would not end up in the footwell. I have experienced previous footwell leaks (not in a BMW, usually Japanese cars) and it is always a HVAC issue, like condensation on ducts or water ingress through the pipes
Good luck, once that is resolved I hope you enjoy 😁

[///MPhatic]

Originally Posted by Beenz

1. Only pay close attention to posts from actual CS owners. The rest is mostly noise, and largely misguided.

Elitism at its best.

I'd test my CS knowledge against yours any day.

[aroundelway]

I'd test my CS knowledge against yours any day.

I would hardy call the CS carbon roof an aesthetic only component as you did above. It's not a cap like you see in so many other cars, it is a structural element.

I've been in the BMW club for years, active at auto-X, plenty of cars in my sample size, I've never heard of any problems with the carbon capped roofs.

Anecdotal of course, but then so is your experience.

[chris719]

Originally Posted by aroundelway

I would hardy call the CS carbon roof an aesthetic only component as you did above. It's not a cap like you see in so many other cars, it is a structural element.

I've been in the BMW club for years, active at auto-X, plenty of cars in my sample size, I've never heard of any problems with the carbon capped roofs.

Anecdotal of course, but then so is your experience.

The only issue with the regular carbon roofs is that they delaminate very often. If you look at older E92 and F8x cars it is extremely common. It's from UV and/or rock chips. I would not plan to own any BMW with a carbon roof long-term without PPF on it. That goes double for the CS roof since it's structural and replacement is even harder.

[///MPhatic]

Originally Posted by aroundelway

I would hardy call the CS carbon roof an aesthetic only component as you did above. It's not a cap like you see in so many other cars, it is a structural element.

I've been in the BMW club for years, active at auto-X, plenty of cars in my sample size, I've never heard of any problems with the carbon capped roofs.

Anecdotal of course, but then so is your experience.

Let me clarify.

I don't care what the reasoning is for it, God could not find the difference in time on a track between a steel and carbon roof, and we all know that steel is stiffer than carbon fiber (just not by weight).

As far as problems with them, I think you need to do more research instead of just talking shop. Ask these guys directly what problems they have had. Look at them closely for yourself. I'm not saying they all leak, far from that, I'm saying they all have issues in time, mostly due to the top layer delaminating. UV kills the resin over time, and any sort of stresses put on the car just exacerbates it. There are NO such problems with steel roofs.

So you tell me, if it's not better, but it's prettier, and a selling point, but has more issues, is it not an aesthetic sales pitch? I think it is, and always has been.

[aroundelway]

Why would the capped roofs leak with delamination? They are just a cap on top of a steel/aluminium roof, it's purely cosmetic.

Reducing weight is a good thing overall, reducing weight at the end of polar moment, in places like roofs is even better.

Having a structural roof made of carbon is an objectively better solution.

I can tell you are not an engineer, and the problem with that is, many people who own CS's are. I bet they are reading this with the same grin I am, and we all certainly don't know that steel is stiffer than CF by the way.

[chris719]

Originally Posted by aroundelway

Why would the capped roofs leak with delamination? They are just a cap on top of a steel/aluminium roof, it's purely cosmetic.

Those non-CS roofs aren't caps over metal. They are carbon fiber, but they are thin. The roof bows are the structural elements and are CFRP also. No one said they leak I think, but they do delaminate often.

I hope you have PPF because your roof will also be prone to delamination if the clear is compromised by UV or rock chips.

[M3R1]

Originally Posted by chris719

Those non-CS roofs aren't caps over metal. They are carbon fiber, but they are thin. The roof bows are the structural elements and are CFRP also. No one said they leak I think, but they do delaminate often.

I hope you have PPF because your roof will also be prone to delamination if the clear is compromised by UV or rock chips.

I do!

We shall see what time does to her, I'm in for the long haul. I will post an update in 10yrs...

[bruiser135msport]

Originally Posted by fastbul

Hi all

New member here. I bought a CS a few weeks ago and quickly realised water was leaking in to the passenger footwell. I took the car in to a dealer last week and they tell me the roof is becoming un-stuck (I can’t think of a better way of saying the roof is coming off). It’s now going back to BMW uk for a replacement roof. Has anyone else had this problem.

Thanks
Tony

Hi
Please let us know the exact results from BMW Uk about repairs and what happened with your Carbon Fibre Roof .

We all wish you the best outcome from all of us on the forum .

Also take with a “grain of salt” any members without any experience with Carbon Fibre Roofs .

BMW so far have replaced all faulty roofs but they do require expert repairs supervised by approved BMW Technicians and BMW AG Germany .

All the best .

Cheers
Bruce

[Reddevils7]

Originally Posted by M3R1

I do!

We shall see what time does to her, I'm in for the long haul. I will post an update in 10yrs...

Same. Mine has had ppf since new. Will keep an eye on it long-term. The E92 with 18k miles I just bought was garage kept it's entire life. The cf roof is in excellent condition and it's 13 years old. I will be getting ppf on it if a couple weeks as well. The original ppf on the front of the car is also holding up great. It does have a slight yellow/orange from uv now but that film is also 13 years old and outdated tech