Hi
I have a 53 plate BMW M Sport Convertible with the 18" BMW alloys, recently I had some tyres changed and ever since I have had a handling issue. Over 60MPH and usually on long sweeping motorway bends I can suddenly find myself in the adjoining lane!!!!!! This doesn't mean that in a straight line everything is ok, even here I can end up in the next lane with no warning what so ever!
The obvious answer to this problem would be the tyres because this problem happened in conjunction with them being changed however, this problem occurs randomly, some times I can go round bends (the same bend) with no problems and other times i'm jumping all over the show. I am an experienced driver and have had many cars with low profile tyres and would know straight away if it was purely down to new tyres.
The garage that changed the tyres examined them and confirmed they were balanced correctly but agreed there was a handling problem. Took it to the BMW dealership and they are stating there is nothing wrong with the car!!
Has anyone else had any issues with their E46 handling?
Many Thanks
AOCAL
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Not on an E46, but on an E36, which isn't that different. When the rear suspension trailing arm bushes failed my car the handling deteriorated and it would, apparently randomly, sometimes exhibit severe oversteer on bends. Also seemed less than stable on the straights. Sounds similar to the problems you're having. Despite the garage check I'd look for something like that.
JS
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This problem is on it's way to being solved........I think!
The rear (new) tyres are Dunlop and the front tyres are Michelin Pilots. It would appear that Dunlops website is feeding incorrect information on two counts:
1. They state that the Sport 9000 MFS is OE (Original Equipment) approved by BMW, it now transpires that they aren't because they don't carry a star symbol so they've misled me on their website.
2. Putting point 1 aside for the moment, they also neglect to tell their customers that they should not mix tyre brands and tread formations on this particular vehicle as it totally screws up the Dynamic Stability Control!
So, to fix this problem I need to go and buy a further two more Dunlop tyres at £200 each and throw away my relatively new Michelin Pilots which cost me £200 each about 3 months ago.
Dunlop forwarded me a document where a customer had a 330Ci and had exactly the same problem! So they know about this issue and have done nothing on their website to prevent it happening again and again
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Capture their web site before they change it and try a claim against them they may pay. Worth a try. !! Regards Peter
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Given the DSC can cope with the extreme of tyre wear (ie. the rears wear out long before the fronts) and operate safely I'd be surprised if tyre make and tread pattern would upset it this much. It can monitor only relative wheel speeds. Maybe it's that the two tyre makes have significantly different rolling radii, but I'd be surprised. Does the car's instruction book make any such comment about 'mixing' tyres.
JS
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Hi John S
The cars instruction book states the usual rubbish "Speak to your local friendly BMW garage who would be happy to assist........blah blah"
Maybe because the tyres are so large the issue is emphasised to an extreme. Based on what you say and assuming the tyres did have different rolling radii perhaps over time when the Dunlops wear down and don't have so much grip the problem would become less apparent? (Just thinking out loud)
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Approval star on the sidewall? That's a new one. There is probably a list of BMW 'approved' tyres but I don't believe BMW have their approved tyres marked on the sidewall. I'm sure many other manufacturers have 'approved' tyres - in fact one of my Astra handboks specifies Pirelli or Michelin for the car.
I can't see that the problem will get better on its own, and I find it odd that a stability programme does exactly the opposite of what it's meant to do. If it was my car, I'd get it checked out somewhere else, perhaps swap fronts to rears, try to borrow a pair of wheels from another car to substitute for the new pair of tyres - or your spare (if it's full size) plus another and see if the problem changes or goes away.
JS
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John S
It's always been the case that BMW approved tyres have the star on the sidewall. I'm not sure if this is BMW specific, maybe it just means the tyre is of a certain grade?? Perhaps other vehicle manufacturers state that tyres must have this star also.
Can't swap front to rear as they're different size wheels on the M Sport!!
I've just found an old user manual from a 318SE I used to own and it actually states in there that mixing tread patterns will screw up the Dynamic Stability Control, along with the ABS.
Try the link below to BMW's own Website, it explains at the bottom all of their approved tyres have the star on the sidewall
www.bmw.co.uk/bmwuk/owner/servicing_programmes/ser...3
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Aocal
Well, you live and learn! Owned 2 BMWs and never saw that before. Mind you, I tended to use tyres that were common factory fitments, so I'm sure I was ok. On an E36 with MTech suspension and ASC+T (but not full DCS) I had no problems swapping makes of tyre and ran with Original Bridgestone Turanza (noisy beasts) rear and new Pirelli front without any problems.
JS
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Aocal
I'm surprised that your tyre place doesn't know this one.
When you jack a M-Sport E46 the shorter rear springs can lift off their mounting button inside the rear arm and then sit at a crazy angle.
Just get it on a lift and it's easy to see; release the shock, lever them back in place and it's sorted.
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"So, to fix this problem I need to go and buy a further two more Dunlop tyres at £200 each and throw away my relatively new Michelin Pilots which cost me £200 each about 3 months ago."
The Pilots are by far the best tyres for a 3 Series. Personally I would sling the Dunlops and replace them with Pilots, why did you mix brands in the first place ?
i would try and knock Dunlop over for some compo on this.
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Hi Pugugly
I have always fitted Michelin Pilots and found them to produce quite a lot of road noise, not a ridiculous amount but thought I would try another brand to see if they made a difference. Wish I hadn't bothered now!!
The Dunlops were also slightly cheaper so I thought that if they did prove to be as good and quieter than the Michelin Pilots then I would also save a few quid! I thought it would be risk free as Dunlop clearly stated these tyre were Original Equipment for the M Sport! Liars!!!!!
I have submitted a claim to Dunlop, strangely enough they have stopped reply to my E-Mails now!! I have offered them the opportunity to purchase their Dunlops back from me, i.e give me a refund or provide me with 2 new tyres for the front.
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Hi Screwloose
The car has been returned to the tyre place that fitted the tyres originally, then I took it to a different garage to check it over where the owner actually had an identical vehicle and was aware of the issue with the rear springs and he checked what you said but all was well.
The car has also been to my local BMW Main dealer and all been checked over. They concluded it must be the tyres as they didn't have the approval star on the side wall.
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My Boss asked me to do an errand for him using his 330Ci - when I got back he said what do you think - I didn't go fast it didn't feel right - that was nearly new and he never kept it long after that - all his other BMW's have been fine and the 640 is fantastic.
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Are BMW saying that their suspension only works with particular tyres???
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Yes, pretty much!
The quote from the manual of my old 318SE says......
"The correct wheel and tyre combination has an effect on various systems which could otherwise malfunction, for example ABS, DSC and DBC"
And indeed they appear to be correct based on my experience.
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Certain makes of tyre are recommended by BMW for each tyre size. They are marked with a clearly visible BMW >> designation star '*' on the sidewall of the tyre.
that quote appears only on their "run-flat" tyres page, and not on the other tyre pages.
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It is the case that you must have a star on all tyres. Main dealer & Dunlop confirmed this.
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I believe the 'BMW Approved' tyres are selected to have exactly the same rolling radius. This is important because the DSC system uses wheel speed sensors on each of the four wheels to very precisely calculate wheel speed. Any sustained discrepancy in rolling radius therefore causes a data plausibility error in the DSC ECU and causes it to shut down. I would expect the warning light to come on (the same thing can happen in MB's fitted with a similar system), it may also cause the cruise control to not work properly.
If you don't have the warning light on then I would suspect that your problem is different, and more fundamental. Is the DSC cutting in when you do the sudden land changes etc?
Incidentally, the increasing application of DSC, ESP etc type systems is one reason why I always recommend tyres are rotated. I have suggested it before and be 'shot down' - but with these systems you need the same rolling radius on all tyres and its best to renew them all at once with four of the same type. Rotation every six thousand miles is a good idea IMHO.
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Rotation every six thousand miles is a good idea IMHO.
so how do you do this on a bmw e46 type of car where:
the front and rears are different diameters and
the tyres have a directional tread pattern?
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so how do you do this on a bmw e46 type of car where: the front and rears are different diameters and the tyres have a directional tread pattern?
Well obviously on the E46 (or any other car with differently sized front and read tyres) you can't !! It is not difficult to work that one out surely...?
But there are lots of other cars, with same size front and rears, fitted with these systems (and also AWD) where you can (in fact relatively few cars have different front and rear tyre sizes). Where directional patterns are fitted then you can't do a traditional 'rotation' but you can swap front and rears on the same side.
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Aprilia
No warning lights, I guess the DSC thinks it's doing a good job, obviously it is blissfully unaware the car has odd tyres on it and is reacting to the anomolies caused by the tyres rather than the road, hence the randomness of it.
As stated by someone else, the tyres are different sizes:
Front 225/40R18
Rear 255/35R18
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Which would be programmed into the chip controlling the stability programme;these chips are designed to accept a certain % of difference anyway otherwise it would be going up the wall after the first few thousands of milesand there will be some adaptive strategy built-in.
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CONCLUSION:
Dunlop accepted their website was incorrect and with very few quibbles paid for me to have two new front tyres fitted. So.....10/10 for customer service from Dunlop.
I can now confirm that my car's handling has returned to near perfect so it can be concluded that the BMW M Sport and probably all BMW's MUST have 4 tyres with the same tread pattern or the cars electronics/sensors get extremely upset.
Incidentally, with 4 Dunlop MFS Sports all round the car is much quieter and the cornering is superb. If you put the Stig in the car for a lap with the Dunlops, then the Michelin Pilots I reckon the Dunlops would easily win!!!
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After Dunlop have now sorted my car out it's time to reflect on the pathetic main dealer I took my car to and told me I needed a KDS wheel alignment for £300, fools! Dunlop sniffed it straight away through an E-mail!!!!
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