M40i brakes - design flaw uncovered

[enuff_zed]

Are you just channelling Sebastian Vettel and spending too much time in the gravel ?

On a serious note though, having read all the suggestions to 'fettle it yourself'; I would assume you have a warranty with this car? Knowing that most dealers are like teflon-coated slalom skiers when it comes to avoiding claims, I would think they'd jump at the chance to void your warranty, even if it was for something completely unconnected. "Well sir, as you've done that, how do we know what else you may have tinkered with?"

 

[millview22]

There does not seem to a problem with the non M sport brakes...

 

[Jim S]

Do it NOW Jim!!!

It will catch his attention first thing tomorrow morning.

Follow it up with a phone call if you haven't heard anything back by lunchtime!

I will write up a detailed complaint and send it to Graeme Grieve so that he has it first thing Monday morning and follow it up with a phone call later in the day.

Thanks for your advice. Let's wait and see what happens next.

 

[Jim S]

There doesnt seem to be many owners on here reporting the same thing.
Maybe this isnt a common problem at all and you are just unlucky with the roads you are driving on being littered with stones.
Is it happening around the same areas?

That is part of the problem, there are very few on the roads in the UK. In fact since the new Z4 G29 was launched in March of this year I have never seen another one apart from the red sDrive 20i demonstrator that I test drove, and I only saw it once on the road being driven by another driver on a test drive.

 

[Jim S]

There does not seem to a problem with the non M sport brakes...

Yes, I think the problem is only with the M Sport brakes, which has a different brake shield design.

 

[Jim S]

Maybe this isnt a common problem at all and you are just unlucky with the roads you are driving on being littered with stones.
Is it happening around the same areas?

No, mostly it happens on main roads at different locations even when it appears that there are very few stones on the road. eg yesterday I stopped at the new traffic lights on the main A78 road in Seamill heading towards Largs. When I moved off a stone got stuck in the front nearside brake. I was in a line of traffic and couldn't stop but it managed to free itself after about half a mile of screaming noise.
My theory is that the stone gets onto the inside of the wheel rim and sits there until it drops into the large opening, like an open mouth, at the top of the shield when driving slow and finds its way to the bottom and gets trapped in the small gap between the shield and disc rotor. This gap is only a few mm and the shield is bent inwards towards the brake disc and hard against the track rod end so can't be bent outwards to open up the gap. The shields are very rigid as well and it would be difficult to bend them. :thumbsdown:

 

[Nictrix]

The other thing is that although the same braking setup may be in other models is it only an issue with the Z because you can hear it clearer with the roof down? Or do you hear it with the roof up also?
Im not saying its not a problem, just that owners of other cars with this setup may not hear it and the stones fall out on their own once they are worn down a bit.

 

[Jim S]

The other thing is that although the same braking setup may be in other models is it only an issue with the Z because you can hear it clearer with the roof down? Or do you hear it with the roof up also?
Im not saying its not a problem, just that owners of other cars with this setup may not hear it and the stones fall out on their own once they are worn down a bit.

Oh, you would hear it a hundred metres away, it is that loud. :thumbsdown:

 

[dr_john]

I will write up a detailed complaint and send it to Graeme Grieve so that he has it first thing Monday morning and follow it up with a phone call later in the day.

Thanks for your advice. Let's wait and see what happens next.

Also read up on the Consumer Rights Act (2015), lots of guidance on Google. In my case I found it invaluable in emails and telephone conversations to quote my rights.

 

[Jim S]

I will write up a detailed complaint and send it to Graeme Grieve so that he has it first thing Monday morning and follow it up with a phone call later in the day.

Thanks for your advice. Let's wait and see what happens next.

Also read up on the Consumer Rights Act (2015), lots of guidance on Google. In my case I found it invaluable in emails and telephone conversations to quote my rights.

Thanks dr_john, will read up on Consumer Rights. Detailed email finalised and ready to go but the Yahoo server seems to be down at the moment. Will keep trying to get it away.

 

[dr_john]

For what it's worth, I had a 4 series coupe with Msport brakes a couple of years ago and never had any problems. Probably a totally different shield design however.

I'm glad I don't have Msport brakes on my G29!

 

[TitanTim]

I'd pen a letter to your dealer and BMW head office so its on record to remind them of your concerns and the amount of times you have visited the dealer with this issue, that it looks to be down to poor design etc and state if it happens again you are not prepared to go fishing for stones trapped in the braking system each time it happens. That any resulting damage is down to them to rectify at their cost. Its crazy you having to worry over it and you are reluctant to go any distance in the car. Sounds like its not fit for purpose. Annoys me BMW are reluctant to take any action if they have had few complaints, you are not a valued customer, just a number to them :thumbsdown:

Tim.

 

[Jim S]

I'd pen a letter to your dealer and BMW head office so its on record to remind them of your concerns and the amount of times you have visited the dealer with this issue, that it looks to be down to poor design etc and state if it happens again you are not prepared to go fishing for stones trapped in the braking system each time it happens. That any resulting damage is down to them to rectify at their cost. Its crazy you having to worry over it and you are reluctant to go any distance in the car. Sounds like its not fit for purpose. Annoys me BMW are reluctant to take any action if they have had few complaints, you are not a valued customer, just a number to them :thumbsdown:

Tim.

Yes Tim, I fully agree with you. I have previously written to my dealer and recorded each occurrence in emails to their Service Manager, whom I must say has been very helpful. However, his hands seem to be tied as it is BMW that need to take action to resolve the problem. Yesterday, I also sent a very strong email to Graeme Grieve, BMW UK Managing Director asking him to get involved in an attempt at having the problem properly resolved. I made it quite clear that I was not at all happy with the response received from BMW Technical and that someone of authority needs to take a closer look at the issue and come up with a proper workable solution. In the email I attached the photo that I took of the front brake assembly to highlight what seems to be causing the problem. I now await his response but if it is not positive I will need to look at taking a more legal approach :thumbsdown:

 

[dr_john]

Good to see that you have contacted the UK MD Jim.

Keep us informed of any developments

 

[tec243]

hello, I'm in the Seattle area and went to test drive the m40i and was told there is a recall on them. They'll allow test drives stating they are safe to drive but won't let you buy one at this time. Didn't get a clear understanding of the issue but sounded like a computer mgmt problem. Also sounded like they may still be working to resolve the problem. Anyone else hear about this ?? ...dean

 

[ronk]

Has anyone heard if they are having stone trapping problems in the Toyota equivalent? Albeit a tin top!

 

[Jim S]

hello, I'm in the Seattle area and went to test drive the m40i and was told there is a recall on them. They'll allow test drives stating they are safe to drive but won't let you buy one at this time. Didn't get a clear understanding of the issue but sounded like a computer mgmt problem. Also sounded like they may still be working to resolve the problem. Anyone else hear about this ?? ...dean

Hi Dean, I don’t think that this relates to the brakes so I would suggest that you open a new thread for this one as I’m sure other owners would love to hear about this.

 

[Jim S]

Has anyone heard if they are having stone trapping problems in the Toyota equivalent? Albeit a tin top!

Not sure about this but I have a feeling that Toyota may have used different brake components.

 

[dr_john]

hello, I'm in the Seattle area and went to test drive the m40i and was told there is a recall on them. They'll allow test drives stating they are safe to drive but won't let you buy one at this time. Didn't get a clear understanding of the issue but sounded like a computer mgmt problem. Also sounded like they may still be working to resolve the problem. Anyone else hear about this ?? ...dean

I'm rather suspicious of the Idrive software, strange things keep happening like:-

1) Auto folding mirrors sometimes working, sometimes not
2) Navigation voice assistant suddenly not working
3) Lane guidance lane 'correction' function active when supposedly switched off

Little issues like these which are irritating, but makes me wonder if there are some more serious issues lurking beneath :thumbsdown:

 

[enuff_zed]

hello, I'm in the Seattle area and went to test drive the m40i and was told there is a recall on them. They'll allow test drives stating they are safe to drive but won't let you buy one at this time. Didn't get a clear understanding of the issue but sounded like a computer mgmt problem. Also sounded like they may still be working to resolve the problem. Anyone else hear about this ?? ...dean

I'm rather suspicious of the Idrive software, strange things keep happening like:-

1) Auto folding mirrors sometimes working, sometimes not
2) Navigation voice assistant suddenly not working
3) Lane guidance lane 'correction' function active when supposedly switched off

Little issues like these which are irritating, but makes me wonder if there are some more serious issues lurking beneath :thumbsdown:

As you're in the Seattle area, it's probably only an issue with the 'Max 8' version :wink: