Strange thumping noise issue with a new C43?

[Solari]

So I picked up a new C43 amg around 3 weeks ago and I love it.

I had a blackvue dashcam and autowatch ghost fitted.

In the last week though I have noticed that when I first move off and when I *turn* the car, typically at slow speeds, the car makes intermittent thumping noise. It's really odd. Say, turning out of my driveway onto the road, I get like 5 thumps until I get back to straight aligned wheels. Each thump kind of shudders the car... and it just sounds really wrong.

However after the initial move off process, the car stops doing it. It then starts again at the start of the next trip. So it doesn't last long, but I get usually 10 thumps or so each time I move off.

Anyone have any idea whats going on and can give me some advice??

 

[DSM10000]

The only advice at 3 weeks old is take it back to the dealer.

 

[Graham79]

Yes take it straight back in and it should be fixed or an explanation given at the very least.

The only advice at 3 weeks old is take it back to the dealer.

 

[sirius9]

Sounds like tyres & wheels related? Crabbing?

Is it usually on full turn?

 

[grober]

Sadly you are not alone in experiencing this phenomenon with certain RHD mercedes 4matic models particularly in colder weather. Mercedes' suggested fix is to fit winter tyres to alleviate the problem which they describe as a "characteristic" of the car rather than a fault.
C43 Full lock low speed judder

 

[zipdip]

Well I do not normally disagree with Grober he is one of the most clued up members on here,but a C43 is a car it has a wheel on each corner and if you buy one new it is a expensive car to buy, so you are supposed to accept that when you are on nearly full lock the front wheel/tyre that is on the outside of the turn is going to jump around making a thumping noise,I very much doubt that the op races off his driveway at a rate of knots,what I see happening is that as a whole people on this forum are accepting less and less from MB,by saying they all do that or it is just that model,you might as well say forget that knock in the engine just turn the music up,ok rant over.

 

[grober]

Sorry I may have given the wrong impression here. I was not endorsing Mercedes' "FIX" merely letting the OP know what to expect by way of response from Mercedes. Experience of GLC owners would indicate the best he might expect is a free set of winter tyres if he complains enough.

 

[Deleted member 6183]

My BMW does this when turning on my drive in the cold as well.

It's no big deal.

 

[Solari]

To be honest if I know it's totally harmless then I don't necessarily have an issue. But I just need clarity that it's not something that I should worry about, e.g. because it is damaging the car or because it's indicating something that is wrong with the car that could cause it to be dangerous to drive. What do you guys reckon? Seems like you guys think it's harmless

 

[grober]

If you are in doubt it will do no harm to alert your MB dealer for their response. The fact that it only occurs under specific conditions/times/manoeuvres would indicate it would be deemed a vehicle response rather than a fault which would more likely to be present all the time. Long term one could speculate that the phenomenon is going to stress the front suspension and drivetrain rather more than one might hope. In the short term- keeping a watch on the wear patterns on those front tyres might be wise.

 

[BTB 500]

There are lots of videos showing this "characteristic". Mostly on the GLC but I assume this is the same as you're experiencing:

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[CaptainChaos]

My BMW does this when turning on my drive in the cold as well.

It's no big deal.

My rear wheel drive C350e will do it on summer tyres too.

 

[23 Romeo Tango]

what I see happening is that as a whole people on this forum are accepting less and less from MB,by saying they all do that or it is just that model,you might as well say forget that knock in the engine just turn the music up,ok rant over.

Below is a reply I sent last night to the same query on AMG PL. I have this issue, along with many other Mercedes, Audi, BMW, Porsche..........................owners. You can fight it if you wish (like I did at first), but it is a whole lot of aggravation and frustration with not much progress in the end.

This is a well know issue with a lot of 4 wheel drive cars, not just Mercedes. From the research I've done there are quite a few theories/reasons this happens. Some people say it only happens on right hand drive 4matic Merc's and not left hand dive, some say it's only a certain manufacturer of tyre, some says that it's the Mercedes 4matic system that is the problem. The top and bottom of it is if you search the internet there are reports of this happening throughout lots of makes and models.

Ackermann steering geometry is the main contributing factor to this happening. Tyre compound is also a huge relative factor along with big tyres and low profiles.

Some owners of the same model car, running the same tyres in the same temperature conditions don't have the same results as others. I picked my E63s up in December last year, it had Michelin Pilot Sport 4S's on and skipped like it was going to rattle to bits. The outside edges of the front tyres were shot in no time at all. These summer tyre compounds are no good in the winter months (below 7°C). Come summer time, the tyres didn't skip, no issues at all while we had the warmer weather.

After lots of discussions with my local dealership they finally awarded me a nice healthy cheque towards some winter tyres. My winter tyre of choice is Michelin Pilot Alpin 4.

All I can advise is don't let this spoil the great car that you have. If this issue annoys you so much, fit winter tyres and move on. At first I was so pi55ed when it started happening, I was annoyed that I hadn't been told about this known issue when I purchased the car, but after looking into it I knew I had two options, (1) accept it and move on or (2) return it and loose an amazing car. Knowing that there was a chance the replacement car (different manufacturer) may also have the same issue there was only one answer.

Good luck and hopefully you get the results you are happy with.

 

[BTB 500]

Supposedly LHD GLCs don't have the issue at all ... don't know about other modern 4Matic models.

 

[ash59fifty-uk]

It’s the AMG badge trying to pry itself from the car

On a serious note, search ‘Driver200’ and join his misery by reading his posts about the same thing