Last year my 2019 e-class estate starting getting vibration issues when braking so we had the discs and pads replaced at the local garage (Brembo)
This worked ok but squealed like a pig so were replaced under warranty.
The new set were fine but about a month in vibration started trough the wheel under braking.
The same garage said they checked the brakes and they were not warped etc and it was the left front steering arm that had play in it.
This was replaced. The judering is still there when braking, but the car in general feels less planted , smooth and there is an almost constant high frequency vibration in the car, which does get worse when braking
The invoice says that 4 wheel alignment and wheel balancing was done, so I can’t understand why it’s doing this.
They are having another look on Friday , but they feel it’s a brake issue. I’m not convinced
Could it be a shock on its way out, how do you check that?
The car has done 50k miles. Local roads are shocking, but a lot of the mileage is motorway stuff
Ideas ? Ta
Hello!
Does the high frequency vibration get worse on rougher roads? Is it like you can feel the road surface through the steering wheel? For me this was caused by the big front suspension bushings (you have several arms and multiple bushings, not just one arm) which were just old and tired, although not failed. When researching parts I found many cheap aftermarket parts and these are a bit of a minefield when it comes to rubber parts. There are loads around that will work, but aren't as good as the original MB parts.
If they've only replaced one arm, that seems like a bit of a red flag to me as I would expect both to be replaced similar to how you should replace both shocks. That big fat bushing up front does a lot of work, and the MB fluid filled part is a fairly complex piece of rubber engineering. I doubt the cheapo ones are the same or have the same deformation and twisting characteristics. Even and old vs new MB original one would have different characteristics.
I don't think brakes can really warp despite what traditional garage wisdom says. I would guess it's more likely to be corrosion between the disc and the hub - this always happens, and when removing or replacing discs you need to clean it all off with a wire brush otherwise the disc isn't aligned and it vibrates. It's possible some garages don't do this when changing discs.
Flat spot on the alloy ? Or tyre slightly out of round ?
Increase in load under braking increasing the problem that exists all the time as a high frquency vibration becomes more pronounced. Or they havent fitted the discs properly , or they havent fitted the pads properly or the wheel bearing is on its way out and the load increase makes it worse.
Whats the milage on the chassis?
Local back street garage or MB indy specialist?
Adding to Molgrips post above - what quality/brand of parts did they use? Aftermarket ranges from OEM but in a non MB cardboard box (Lemforder) through to absolute garbage that wouldn't get off the garage ramps before failing. I'd also expect to change both sides of suspension components - if one has failed the other won't be far off.
Regarding 'warping' discs. Have you done any fully loaded car+high speed stops to stationary? .........and then sat with your foot on the brakes? This causes brake pad material to weld to the disc in one spot which then feels like 'warped discs'
What callipers does it have up front? I had really bad occasional vibration on our last caravelle and it turned out to be one of its 4 front pistons was corroded and seizing. As a result just part of the pad continually dragged on the inboard side of the disc. It didn’t warp the disc but made it hot in places and grab the pad resulting in vibration. Rebuilt the calliper with new pistons, service kit and a blast /powder coat and all was well.
agree with molgrips and RNP in that “warping” like you might find on a motorbike or mountain bike is only a thing on unvented discs from 1980s cortina’s and cavs. What I think you get instead on big heavy ventilated discs is surface contamination from cooking them, stopping the car with the pad in one place and not letting them cool off with a run down. A seized piston will do exactly this
I'd take it to a different garage and get better advice. You're current one is playing parts darts which only ever gets more expensive, (for you) as the game progresses.
Look, you've already got about 4 different causes from this thread alone none of which would be a cheap solution.
Aftermarket ranges from OEM but in a non MB cardboard box (Lemforder)
I would caveat that a bit. Whilst Lemforder make some OEM Merc parts, that doesn't mean the aftermarket ones are the same as what you get from MB. I changed engine mounts on my car 2 years ago but they still feel a little bit slack, with engine judder at certain times. The same shape mounts are used by probably 7 or 8 engines on multiple vehicles, and whilst MB may have specced them differently for each variation of engine and car, with different rubber grades or fluid viscosity etc, I bet Lemforder aren't making that many variations for the aftermarket. They probably think 'well the 220 CDI version is nearly the same as the 250 CDI version, no-one'll notice and it'll save us some money' whereas MB may not have.
I'll probably get some from MB later this year and swap them again, I'll let you know if it makes a difference 🙂
Check for any tyre damage, bulges etc. Mud inside the wheels.
Swap wheels front to back to see if anything changes.
Could also be a knackered shock letting the wheel shimmy up and down.
a fairly complex piece of rubber engineering
The best bit about this sentence is that it reminds me that someone, somewhere, has rubber engineer in their job title.
Losing air from that tyre - if so, check the alloy for any 'splits'.
Wheel bearings? My C Class is like this and getting worse but I know the wheel bearings need doing (although they're old skool on a Merc and you can actually tighten them).
I know everyone is only intending to be helpful with these suggestions and previous experience but we've had...
- Wheel bearings
- Engine mounts
- Suspension bushes
- Shock absorbers
- Damaged alloys
- Seized brake calipers
- Warped disks
Kind of goes to prove my point about taking it to a proper garage who knows how to diagnose stuff!
Please don't think I'm intending to cause offence, bit it's always the way with these kinds of questions. Impossible to answer accurately.
Thanks for the responses the forum wouldnt let me reply yesterday 🤣 🤣
Does the high frequency vibration get worse on rougher roads?
Yes. Yesterday was the first time I properly drove the car since having it 'repaired'. At motorway speeds there was a constant shaking ie cups vibrating in the cup holders, headrest visibly moving, although the steering wasnt necessarily vibrating as much just a very small amount. That shakes more when you brake. The steering feels more vague, not planted and the car feels like it moves around a little. Previously this Merc was solid as a rock, not a single vibration. The braking vibration is still there, but post steering arm replacement now the car feels anything but relaxing, planted and calm.
The car had already been back in to have the steering wheel re centred after alignment, and this was still off. Weirdly when I moved my driving position ie so the steering wheel wasnt far from the dashboard the steering wheel became aligned correctly ?!?
The car has auto pilot ie it can drive itself. When I first engaged this it had a right wobbly and couldnt keep the car in a straight line. It got better as time went on, but in the past it would be able to navigate bends on dual carriageways by itself, but now it wanders and has to correct itself, which tends to be more violent and at the last minute.
When they said there was play in the steering arm I asked should both sides be replaced and they said its not necessary. They are taking it back in on Friday. They want me to drive it before and get heat in the drive train/brakes and they will put it straight on a rolling road?? They say that should tell them what is happening independently with each wheel??
All tyres are premium brand and quite new. Some of the alloys have started to corrode but not too badly. 50k miles total on the car 6 years old.
I am going to look elsewhere. I was a little concerned that they said the steering wheel alignment was out because they hadnt realised the steering wheel moves when switching the ignition on/off. Plus when i was waiting for this to be done, 2 customers came in. 1 saying the spring they had replaced was making a loud knocking noise (to which they replied maybe its not seated properly) 2 A person came in saying the brakes they had fitted were burning.
I am going to look for an proper independent Merc place. However in the deepest darkest Shropshire/Welsh Boarders, there appears to be nothing coming up so far when searching 🙁
Despite the tyres being new, check for damage - especially inside edges.
Hmmmmm, was the car new to you, or new new straight from the factory?
Also, this:-
The car had already been back in to have the steering wheel re centred after alignment, and this was still off. Weirdly when I moved my driving position ie so the steering wheel wasnt far from the dashboard the steering wheel became aligned correctly ?!?
Rings a couple of different alarm bells, have they put something back together wrong and used the "wrong bit" to adjust. i.e. uneven length links somewhere, or the steering shaft sitting xx degrees off when going straight ahead? (so the whole rack is off centre).
Or the shaft could be twisted/bent (if it wasn't a new car when you got it), the steering wheel alignment changing as you adjust the wheel isn't really normal.
Also, if it's a second hand car, and you've needed what appears to be a fair bit of alignment work done, has it been crashed? Have seen issues like this when the subframe is slightly out of position, or one of the suspension mounting points is twisted.
Probably too far to go but my place in Cardiff (Cassley Automotive) is pretty good.
You can check for play by rocking a wheel backwards and forwards, like checking for headset play on a bike. Put your hand on top of the front wheel then push and pull forwards and backwards, then do it again in and out. You need a fair bit of force and you need to get some resonance going. This can also reveal slack front wheel bearings (if 2WD) but that isn't necessarily a problem as there can be a tiny bit of play in spec.
If you do the rocking forward and back at the rear you will get a clunk from the parking brake (on my model, not sure yours) or the driveshaft lash (normal) which makes it hard to detect suspension play but you might get something. It sounds slightly different.
The vibration in car does sound like the front bushings, but strange that it should have suddenly come on after a brake change.
I know everyone is only intending to be helpful with these suggestions and previous experience but we've had...
- Wheel bearings
- Engine mounts
- Suspension bushes
- Shock absorbers
- Damaged alloys
- Seized brake calipers
- Warped disks
Kind of goes to prove my point about taking it to a proper garage who knows how to diagnose stuff!
Has the fluffer valve been checked? Is the fallopian tube blocked?
In seriousness - with all the talk of autodriving and misaligned wheel I'd be taking it to a decent MB specialist. It sounds like your garage doesn't have the expertise.
Have you tried swapping the front wheel to the rears to de bunk the theory of buckled rims . ?
I wonder if the auto steering system is doing something it shouldn't be and that's making the vibration.
Where were the brembo pads and disks bought ?
Fairly wide spread on the socials just now that they are having quality issues on supply of pads in particular being off square and only contacting portions of the disk.
Mostly through autodoc but I guess that's because no one actually uses ecp any more.
Just been back in this morning
I went out with one lad. He said can definitely feel it, but feels like the rear not front
When you really brake hard ie to point of ABS there is no vibration at all in the pedal. Technician queried rear shock absorber.
But then when we got back to the garage he checked al tyres and said they were ‘stepping’. There is no way to switch front and rear tyres as they are different sizes.
Molgrips - the vibration hasn’t come after brake change. It was there before, probably about a year ago. I took it in saying te vibration symptoms under braking so they swapped the brakes. The issue didn’t return straight away but it came back not long after
Now at a loss where to take it
To be clear the vibration is there all the time. Worse when braking then disappears with hard braking.
The one time I've seen this it disappeared when I retightened the wheels. Something is loose and slopping around in the suspension, not the brakes. When you brake hard the loading from the deceleration holds everything tight.
If this is ties to the steering arm(s) is very possible, and I'd be scared of using the car. Got another garage who can look at and check this pronto?
You could try taking it to an MOT station that has a wobble ramp (not sure if that's the official name). It properly works all the suspension whilst the tester is underneath inspecting, a surprising amount of flex on my campervan last month but all good thankfully! I also had a work van that went for three tracking attempts where they couldn't get it to drive straight or centre the wheel, a few weeks later I discovered I could move the front wheels and it was the top mounts on the shocks were all knackered and moving about!
Yes what wbo says sounds reasonable. Something in there is loose or slack which is resonating - a bushing or a bolt. Or even a damaged subframe as there have been rust problems, but I'd expect that on an earlier model.
But then when we got back to the garage he checked al tyres and said they were ‘stepping’
Yeah that happens when the suspension is out of whack. It was a broken spring on my Passat that did it, but you might have air springs. They've done the alignment, as you say, but if something's slack then the alignment will be different when driving than when static on the alignment ramp.
You might have to take it to Merc - they are expensive but they are good and they know what they are on about - at least mine does.
