Ride Quality On My 640d Msport

[13 NF]

Hi Folks

Had the GC for about a 6 weeks, its a Msport without VDC or adaptive drive.

I am finding the quality of the ride very poor, the car is unsettled on any poor road surface. If cornering quickly ( But not mad) the car bounces over the road, a real feeling that your going to lose the back end.It has that feeling you get when you drive a van unladed.

The car also appears to bottom out on traffic ramps/speed humps at slow speeds.The back wheels in particular. I have noticed the car wollows over the speed ramps, reminds me of the film UNCLE BUCK and his beat up Caddy.

Another problem is that the vibration through the car, if you put your hand on the head rests when your idling you can feel the vibration.

I have those BMW DVD screens which attach to the head rests and I cannot use them as they make so much noise and vibration.

On a car with so hype, I am really pissed off, no wonder I got a good deal.

I really regret this purchase, it should have had VDC and I HAD CONVINCED MY SELF IT HAD.

Anyone else with simlar issues, the Tech at the dealer appeared to almost know the complaint, I am awaiting a KDS ( The point of that I have no idea)
He is going to test drive it and let me know.

Retro fit adaptive drive!

Help

[Mentos]

I don't think retrofit of adaptive suspension is going to be a viable option. Aside from it probably being financially prohibitive, it may also open up a can of worms come resale/warranty claim.

Assuming you've done the basics, check the tyre pressures, alloys, tyres for damage, dealers checked your suspension, etc. The least pain full avenues to explore now are ditching the run flats, if that doesn't work try a smaller alloy.

Sorry your new car experience has been so bad, hopefully its a suspension issue or something similar which the dealer can resolve.

[m630]

Hello,

Apologies on your experience, it does sound out of ordinary from my experience with the GC, which is as a very sporty, compliant, luxurious ride. In terms of dynamic suspension, were you told the car had it by the dealer or was it an oversite on your part? I have no such vibrations but perhaps that is due to the Diesel engine...good luck...cheers

[13 NF]

I think I know the answer, I was convinced it had VDC, it was my oversight.

The car is lovely, but its just not that great in my spec, whats a real same is for the £1100 extra it could have been great.

The dealer is having a look in the next two weeks

Thanks m630 and Mentos

I will keep you up to date

I cant drive it as it is!

[Jon D]

I currently have the 640i convertible on stock suspension, which I imagine to be softer than your M Sport, but I know what you mean about the rear end tramping when cornering on uneven surfaces. I only notice it very occasionally when I'm cornering on bend with an adverse camber and at quite slow speed, but it can be somewhat unnerving.
I bought my car used (1 year old with just 1200 miles) and the deal was too good to refuse (45% off list). Had I bought new I would definitely have opted for the AD+VDC - I had it on my previous car, an F10 535d M Sport and I found it amazingly effective.
As to your vibration through the head restraints - if it's happening with the car stationary, it can only be engine related and it most definitely should not be noticeable. The engine in my 535d is basically the same unit as fitted to your 640d and it should be very smooth at all RPM settings. I also test drove an F13 640d a while back and I found the engine and ride to be remarkably smooth.
If your vibration is happening when the car's moving and you find that the frequency alters with road speed, it will be transmission or wheel related and, as it's coming through the seat, that would most likely point to transmission or rear wheel balance/bearing.
Hope that helps - good luck at the dealer.

[13 NF]

Thanks very much,glad someone understands my issues, I went to dealer today they are good guys, and I feel they are aware of these issues, but I dont think any thing can be done.

It may be chopped in for something else, but I dont think the figures will add up. I did get a good deal and 0% finance!

I love the car, but its far from the ultimate driving machine

Its a shame

I will keep you upto date

[BillCB]

When I've experienced the sort of "hopping sideways" on corners, as you describe, it's been because I had a very inaccurate tire gauge and the tires were far too hard.

But I assume you have checked pressures carefully.

Bill

[Holland Harry]

Just get rid of the runflat tires and you will not recognise the car again! I did the same on mine and it rides beautiful!

[13 NF]

Yes I have checked the tyre pressures, althought the dealer had to change a wheel, it came with a chunk out of the wheel.The wheel was replace some weeks later.

They want to do a KDS, which is a 4 wheel balance!

Its getting sorted at the end of the month,interesting point on run flats I will inquire.

Thanks for your thoughts.

[Jon D]

Originally Posted by 13 NF

Yes I have checked the tyre pressures, althought the dealer had to change a wheel, it came with a chunk out of the wheel.The wheel was replace some weeks later.

They want to do a KDS, which is a 4 wheel balance!

Its getting sorted at the end of the month,interesting point on run flats I will inquire.

Thanks for your thoughts.

KDS is a full suspension geometry and alignment check and does not include wheel balance; that is a separate check and I suggest that you politely ask your dealer if they'll be including it with the KDS.
BillCD (above) is absolutely correct in stating that tyre pressures play a very important part in affecting road holding and I should have mentioned this earlier. I check mine weekly using a certified dial-type gauge (Race X £10) and, by experimentation, have found that I get the best ride, road holding and most even wear by keeping them at 1psi above minimum, Of course, this should be increased when loading the car with passenger and luggage and for this I have a small 12v 'Ring' portable compressor.

[Jon D]

Originally Posted by Holland Harry

Just get rid of the runflat tires and you will not recognise the car again! I did the same on mine and it rides beautiful!

I've read many positive comments about this and plan on changing to non-RF when mine need replacing.
Please could you tell me what brand of tyre you chose and how much of a pressure adjustment (up or down) you made?
Thanks.

[Jon D]

Originally Posted by 13 NF

...it came with a chunk out of the wheel...

It requires a significant impact to to take a chunk out of the wheel - definitely more than enough to alter the alignment, affect wheel balance and possibly damage the bearing.
Did you ask them how the wheel came to be damaged and, in addition to changing it, what checks they made prior to you accepting the car? Sounds like something might have happened on the dealer's pre-delivery test drive.
I mentioned earlier that a vibration in the head-rest with the car in motion would be caused by either a transmission or rear wheel problem - which wheel was damaged?
Something is definitely not right here and I think the damaged wheel is where your problems originate from.

[13 NF]

Hi Jon D

Some good points, I did realise that the KDS is more than a wheel balance but in my mind its suspension set up.

This morning coming to work I left M6 Nth to join M65, at the start of the slip road to join the M65 the chamber goes one way then another, my car just feels so unsettled and I have little or no faith in retaining any grip if the road was wet. I entered the slip road at a moderate speed. Even on stock suspension this car should handle great.

The wheel that was replaced wasn't done by PDI guy, as I had a conversation with the Service Manager whom I know very well he explained that the car left his site perfect and went over to the showroom (dealership is seperate to service aftercare area about 1/2 mile)

But I got thinking that the vibration on the head rest, just is not right. I don't remember it on my 535d or last generation 635d Coupe, or for that matter my wifes new X5(Which you could forgive a little vibration going on)

So I need to stress the vibration issue, but it's bad when the car is stationary. So engine mounts?(When I say bad we are not talking London Taxi But on a car of that price, no vibration should be the thing.

Thanks for your thougths

[Jon D]

If the vibration is present with the car stationary, it can only be engine related - as you say, possibly the mounts, but it could be flywheel, crank or from various other sources.
As to the handling issue - it sounds far worse than the low-speed rear end tramp I very occasionally experience. Hopefully this will be rectified by the alignment check, but tyre pressures are very important too. Splash out ten quid on a 'Race X' gauge and experiment between the upper and lower limits, but always maintain identical pressures across each axle.

[13 NF]

Thanks will do

I will let you know in a couple of weeks, thanks for your advice.

[HighlandPete]

Originally Posted by 13 NF

Thanks will do

I will let you know in a couple of weeks, thanks for your advice.

Have you made any progress?

On the ride quality issue, what wheel size are you running, not 20" wheels are they? Both sizes run 275 section on the rear, that won't help on roads with strange and varied contours.

How many miles has the engine driven? May be worth trying a premium fuel like BP Ultimate, just to see if combustion changes and runs smoother.

HighlandPete

[Jon D]

Originally Posted by HighlandPete

...On the ride quality issue, what wheel size are you running, not 20" wheels are they? Both sizes run 275 section on the rear, that won't help on roads with strange and varied contours...

Hi Pete,
Interesting comment on the 275 section rears. I have 20s on my 640i and occasionally get an unsettling rear end tramping, similar to the op's, when cornering on an uneven surface with an adverse camber. It's only been apparent on a couple of local roundabouts and at quite a low speed.
The car feels really well planted when cornering at higher speeds through a series of sweeping bends, but the low speed tramping has left me feeling less confident than I did in my F10 on 18" wheels.
I'd have thought that the wider 275 section would give more grip, but it appears to be the reverse.
As always, would appreciate your thoughts on the theory - thanks,
Jon

[Holland Harry]

Originally Posted by Jon D

I've read many positive comments about this and plan on changing to non-RF when mine need replacing.
Please could you tell me what brand of tyre you chose and how much of a pressure adjustment (up or down) you made?
Thanks.

Sorry for the late reaction! At the moment I have Pirelli P Zero on the car! These tyres are amazing. A friend of mine ordered a M6 Gran Coupe, his car will be delivered with Michelin Pilot Super Sport tyres. So I am planning to order them also! Hope this helps you. You won't regret it.

Good luck with making a choice.

[HighlandPete]

The roundabout scenario, where you feel the wheels fighting for grip, as road cambers are all over the place, clearly illustrate that even an average width tyre has issues with following the changes. Widen the profile and lower the aspect ratio and that limitation is just made worse.

From my understanding, camber control is even more critical to wider profiles, particularly shows up when road surfaces are unpredictable. Similar to wider wheels/tyres having more issues with tram-lining, we get similar issues with rear wheel grip and a sort of side hop when the tyre can't 'hug' the road surface across the contact patch.

Run-flats make this all more sensitive in my experience, as the stiffer sidewalls make it more unpredictable on the limits of grip. Not so progressive in the way a tyre breaks away.

I remember trying my first E91 3-series on a staggered wheel setup, shod with run-flat tyres. Took the car out on some interesting road surfaces where the cambers and repairs were more challenging. The rear end was very lively, almost as if it was on ice. Don't get me wrong, on decent surfaces the car was well planted and secure, but the working envelope was far too narrow for the sort of roads I drive. I tried a second E91 on the same diameter rims, but a 'square' tyre setup and the car was much more predictable on the same roads. For me a wider working envelope.

For my F11 I've kept to an 18" square setup, and don't have any issues with rear grip or strange wheel hop.

HighlandPete

[13 NF]

I have the dealership taking the car whilst I am on holiday next week.

Driven today, just got to be something wrong, vibration through whole car seat was squeaking and dash has now got a rattle.

Also noticed that the i drive driver information now says the front brakes has 33k left on them and the rear have 16k on them! the car has done 2k miles?

Hope they find something

Speak in June

[13 NF]

So got the car back today.

The same issues,but now steering wheel is 10 degrees off.

Ride terrible, just as before, steering constantly needs recorrecting on motorway.

Just so disappointed, the car looks great interior is fab, but drive

Hopefully excellent dealer may help, if not its bye bye BMW.

I will up date you.

[13 NF]

So its been a wait, my Dealer has got hold of a GC with VDC for me to try.

Its a BMW UK car so its pretty loaded, its all the stuff I have had before except the LED's which look different.

I drove the car for about two hours today and have the car for a further two days.

My initial experience its that the VDC, makes a improvement to the ride, but it seams to not make any difference at all at the moments when you need it to dampen a pot hole or roads surface.

The comfort plus on the motorway allows a better ride, but again the same road I go down in the other car, this car vibrates just as bad.

I will give it a go over next two days and report back.

But sorry the 6 GC car is looking like its not really sorted at all, the ride on both the cars is not great.

It could be the 20 inch wheels with run flats

Looks good in and out!

But not the greatest drive dynamics.