640 GC shudder under heavy braking

[CSK423]

Car has nearly ticked 20k miles and has over 10k left on the front brakes (bit more on the back).

3 Tyres have around 3-4mm all round aswell, one only has 5k miles on it.

Under light braking from 70mph there is no shudder but as soon as you apply a bit more pressure the car shudders slightly almost as if you're going over a bumpy surface. The steering wheel ever ever so slightly shakes, again feels as if the road surface is bumpy. No shaking through the brake pedal.

I didn't notice it and must have gradually grown a custom to it, it was the wife as a passenger that commented and drew my attention to it. Now I feel it all the time !....to the point I'm starting to think it's getting worse.

I bent a wheel around 5k miles ago, now repaired and new tyre but felt not shaking during or after that and it's been into BMW for a service where I specifically asked them to check the suspension.

All tyres are wearing correctly so no misalignment issues.

Anyone came across this before ? I'm starting to think a sticky caliper ?

[anonymous-user]

My 5 series does it. Brake from 70+ it's OK and at low speeds it's OK. You feel it between about 60 and 40.

It's apparently very common and often down to the discs having some pad pick up or localised corrosion that causes the vibration. I plan to have the front discs skimmed unless someone on here knows better, which may well be the case.

My car was fine until it was left standing outside for a month back in February, it's normally garaged. I don't know if that's connected but I'm positive that's when it started.

[Theophany]

Pitted discs seems to be the cause on my 645ci. Seems to be pretty common on E6x cars, not sure about F gen cars. I found that a proper slamming of the anchors from decent speed has definitely reduced the amount of shimmy I was getting from the wheel. Not an ideal solution, but seems to have worked (and stopped me from ploughing into the tool that pulled out in front of me).

[anonymous-user]

I understand the F10 is quite prone to it. I've tried the heavy braking thing but it didn't make much difference.

[CSK423]

REALIST123 said:

My 5 series does it. Brake from 70+ it's OK and at low speeds it's OK. You feel it between about 60 and 40.

It's apparently very common and often down to the discs having some pad pick up or localised corrosion that causes the vibration. I plan to have the front discs skimmed unless someone on here knows better, which may well be the case.

My car was fine until it was left standing outside for a month back in February, it's normally garaged. I don't know if that's connected but I'm positive that's when it started.

Interesting as the car sat for nearly 3 weeks on my driveway last month.

[s4avant]

I had this problem on my 2008 520d touring.
A front brake disc had been slightly warped by a sticking brake caliper.
Once the caliper was sorted and the disc replaced, the problem disappeared.

[Depthhoar]

E39s suffer from this problem too. A lot. Can be any one of a multitude of things, sometimes a combination of factors.

Common causes are worn bushes on front suspension arms, partially seized calipers, brake disc runout, pad transfer, failing front wheel bearings etc etc. It's quite a list and the reason why diagnosing is tricky.

Since the car's been unused for a while I'd start by investigating the brake calipers. Easy enough to check with one of those cheap laser thermometer things - the binding caliper will make that particular disc warmer/hotter than the other side.

Good luck!

[anonymous-user]

Depthhoar said:

E39s suffer from this problem too. A lot. Can be any one of a multitude of things, sometimes a combination of factors.

Common causes are worn bushes on front suspension arms, partially seized calipers, brake disc runout, pad transfer, failing front wheel bearings etc etc. It's quite a list and the reason why diagnosing is tricky.

Since the car's been unused for a while I'd start by investigating the brake calipers. Easy enough to check with one of those cheap laser thermometer things - the binding caliper will make that particular disc warmer/hotter than the other side.

Good luck!

My cars just over 2yo, 25k (22 when the problem started) I would hope it's not bushes. I have an IR pyrometer so I'll see if any brakes are getting hotter than others.

I'm fairly convinced it's related to it being stood outside but will investigate any suggestions.

I'd take it to the dealer but expect to be told "new discs and pads, not under warranty". Is that wrong of me?

[Depthhoar]

REALIST123 said:

My cars just over 2yo, 25k (22 when the problem started) I would hope it's not bushes. I have an IR pyrometer so I'll see if any brakes are getting hotter than others.

I'm fairly convinced it's related to it being stood outside but will investigate any suggestions.

I'd take it to the dealer but expect to be told "new discs and pads, not under warranty". Is that wrong of me?

Really shouldn't be happening on such a new car, unless the discs are totally corroded. Bushes after 25k miles of normal driving should function almost as well as new ones. Front control arm bushes on the E39 tend to deteriorate quickly (and noticeably) after about 60-70k miles.

Some say that the 'warped' brake discs diagnosis is overstated. Occasional OE issues with quality control, yes. Cheap and poorly manufactured aftermarket discs, yes. (Not all aftermarket discs are poor though since ATE et al are OE suppliers and supply the aftermarket as well). Discs will show excessive run out ('warping') when they are nearing their wear limit, which in part depends on how hard the car has been driven. Pad transfer due to poor bedding in - and holding the car on the foot brake in heavy congestion immediately after a hot run - can induce the the symptoms of 'warping'. Re-bedding in the pads can often clear this. Having said all that, some say bedding in brakes is old hat!

I too fear the "it's yer discs, mate. They're warped." diagnosis on my M5 since the floating discs are a king's ransom from the dealer and only a little cheaper on the aftermarket. Machining the discs is an option for short term relief but often seems to hasten the demise of the discs and the return of judder.

I eliminated slight judder on my M5 by replacing a failing front wheel bearing!

I posted on another forum about this BMW E39 judder issue. It's speculative but might be worth a read:

http://forum.bmw5.co.uk/topic/111698-will-this-sto...

[arcticfire]

Another common problem, especially with autos is braking hard coming off from high speed to a standstill such as a junction or roundabout and keeping the brakes on. The heat can cause the pads to leave crap on the discs.

[anonymous-user]

Thanks for the replies. Speaking for myself, my car (530D) has a pretty easy life. It's not a car I push on in, more cruise along. I always use the autohold so the car is held on the rear brakes in traffic.

I also use cruise a lot too, which, I guess, is why my rear pads are forecast to need changing about 32K but the fronts about 40K. Looking at the pads, the rear estimate looks about right but the fronts look like they'd go on a lot longer than 40K.

If it were the rear brakes that were causing the problem, it would be a little more understandable in my case but I'm pretty sure it's the front, it's definitely felt through the steering as well as the pedal.

Looking on the web this is a very common issue, often sorted by having the discs skimmed.

[CSK423]

Turns out it’s a warped disc off side front only and the reason it’s warp is due to the heat not being dissipated properly...and why hasn’t it been dissipated ? because the alloy has been refurbed and in doing so the hub of the alloy was painted which meant the heat transfer from the disc to the alloy hub is unable to happen and in turn warps the disc with excessive heat build up.

Google confirms this theory with many BMW owners experiencing the same thing.

The dealer removed the hub paint on the alloy to stop it getting any worse (won’t get better) they wouldn’t skim the disc but suggested new front discs and pads at £700.

I’m going to get the disc skimmed at £95 as front brakes are reading11k miles left, if it was 4/5k I would change them.

[gareth h]

I've had a couple of pairs of discs skimmed, it only solved the problem in the short term, if it was me I'd bite the bullet and fit new discs.

[ashway]

CSK423 said:

Turns out it’s a warped disc off side front only and the reason it’s warp is due to the heat not being dissipated properly...and why hasn’t it been dissipated ? because the alloy has been refurbed and in doing so the hub of the alloy was painted which meant the heat transfer from the disc to the alloy hub is unable to happen and in turn warps the disc with excessive heat build up.

Google confirms this theory with many BMW owners experiencing the same thing.

The dealer removed the hub paint on the alloy to stop it getting any worse (won’t get better) they wouldn’t skim the disc but suggested new front discs and pads at £700.

I’m going to get the disc skimmed at £95 as front brakes are reading11k miles left, if it was 4/5k I would change them.

Ive had loads of alloys referred over the years but never had this problem, which part of the wheel has been painted that shouldn't have. Is it the surface of the wheel that mates to the wheel hub. The hub itself is not part of the wheel so not sure why that would have been painted?

[CSK423]

ashway said:

Ive had loads of alloys referred over the years but never had this problem, which part of the wheel has been painted that shouldn't have. Is it the surface of the wheel that mates to the wheel hub. The hub itself is not part of the wheel so not sure why that would have been painted?

Yes the surface of the wheel that mates with the hub.

[anonymous-user]

Whilst perhaps not being good practice to paint that surface, for mounting accuracy reasons, I struggle to accept that that could cause a disc to warp. Warped discs are very rare, in fact, they more normally suffer from surface issues that cause vibration.

A painted surface might theoretically slow the rate at which the heat passed through to the wheel but why would that cause a disc to warp?

Sounds like a convenient peg to hang it on to me.

I've still got the issue, original wheels still fitted. Just trying to decide whether to risk the dealer's fairy tales or just have the discs skimmed......

[CSK423]

REALIST123 said:

Whilst perhaps not being good practice to paint that surface, for mounting accuracy reasons, I struggle to accept that that could cause a disc to warp. Warped discs are very rare, in fact, they more normally suffer from surface issues that cause vibration.

A painted surface might theoretically slow the rate at which the heat passed through to the wheel but why would that cause a disc to warp?

Sounds like a convenient peg to hang it on to me.

I've still got the issue, original wheels still fitted. Just trying to decide whether to risk the dealer's fairy tales or just have the discs skimmed......

I checked both fronts and the OSF (refurbed wheel) drags on the pad when spun, the NSF (original finish) does not. It's not able to dissipate enough heat which results in the disc warping, this has been after circa 5k miles and generally braking from motorway speeds, it's taken a while and high speed braking to warp it. I have no doubt someone tootling around town probably won't see this level of heat build up and will never suffer the same consequences or it'll take a lot more mileage.

I would challenge your dealer and see what response you get, you don't ask you don't get.

[anonymous-user]

CSK423 said:

REALIST123 said:

Whilst perhaps not being good practice to paint that surface, for mounting accuracy reasons, I struggle to accept that that could cause a disc to warp. Warped discs are very rare, in fact, they more normally suffer from surface issues that cause vibration.

A painted surface might theoretically slow the rate at which the heat passed through to the wheel but why would that cause a disc to warp?

Sounds like a convenient peg to hang it on to me.

I've still got the issue, original wheels still fitted. Just trying to decide whether to risk the dealer's fairy tales or just have the discs skimmed......

I checked both fronts and the OSF (refurbed wheel) drags on the pad when spun, the NSF (original finish) does not. It's not able to dissipate enough heat which results in the disc warping, this has been after circa 5k miles and generally braking from motorway speeds, it's taken a while and high speed braking to warp it. I have no doubt someone tootling around town probably won't see this level of heat build up and will never suffer the same consequences or it'll take a lot more mileage.

I would challenge your dealer and see what response you get, you don't ask you don't get.

Yes, you're right I should do that. I'll get my arse into gear and report back!

[wibblebrain]

I think judder can be caused by buckled wheels.

I say this with some confidence because my car has been running fine for the last 6 months.

I just swapped to some newly eBay purchased 19" wheels with hew tyre and have been getting vibration in the car. I took the wheels and had them balanced again. The fitter commented that one of the wheels was buckled and balanced them as best he could. However I am still getting the vibration at certain speeds and under braking.

I've put the winter wheels/tyres back on the the problem has gone.

So I'm taking the summer wheels to Lepsons to get them straightened.

[Dino D]

CSK423 said:

I checked both fronts and the OSF (refurbed wheel) drags on the pad when spun, the NSF (original finish) does not. It's not able to dissipate enough heat which results in the disc warping, this has been after circa 5k miles and generally braking from motorway speeds, it's taken a while and high speed braking to warp it. I have no doubt someone tootling around town probably won't see this level of heat build up and will never suffer the same consequences or it'll take a lot more mileage.

I would challenge your dealer and see what response you get, you don't ask you don't get.

I'm trying to work out how the wheel/paint can cause the pad to drag on the disc?
Or have I missed something?
It's the dragging that causes the heat regardless of what wheel is on that side if have thought?