See if you can eliminate the noise being the reverse camera flap.

See

https://www.aclassclub.co.uk/posts/210388/

 

Thanks. I wondered if it was the camera/flap closing as I pulled away so your post has given me something to look into.

 

Else it might be rear diff related.

There has been a spate of forum members reporting noise, behaviour and oil quality issues in the rear diff.

See posts #227 & #228 in this thread:

https://www.aclassclub.co.uk/posts/219858/

(Read all 200+ posts if you’re interested in the intricacies of the different fluids used in the rear diff )

 

Thanks @veeeight - I did also wonder if it was diff related but hoped not as the noise it so subtle.

That's got me wondering if it's a good idea to get it looked at.

Do you know the standard practices at Mercedes for looking into issues under the manufacturer warranty?

Owning other marques in the past I'd simply book it in and ask them to look at it but I'm curious if Mercedes has mandatory diagnostic fees that you have to pay even under warranty. (I would call them and ask but I'm multitasking in a work call as I type this)

 

It varies as to how friendly or accommodating your dealer is.

if you bought the car from them, the more likely they will attend to it without the investigation fee.

Used AMG’s purchased from a M-B dealer come with 2 years warranty.

 

Thanks. I did step out for 10 minutes and made two calls to two different local service centres - what a palaver!

I used to own BMWs and you'd call the service centre, ask to be put through to the service team and they'd get it booked in and looked at under warranty.

Mercedes, on the other hand, won't put me through to the service teams but instead, take 5 minutes writing an email to their colleagues sitting 10 feet away and insist they'll have to call me back (when I'll probably be back in my meeting).

This was after speaking to central booking who said, quote "Investigation fee? erm maybe, dunno, not sure, might be.. Who knows?"

I might just drive to my closest service centre tomorrow and speak to them in person.

 

Press the SOS button. That might speed it up.

When I had an underbody noise. I took it in to my local MB. A mechanic took it away there and then and came back with the cause.

 

Welcome to the Mercedes A-Class ownership experience

On the other hand, S-Class owners are treated like royalty

 

You have to laugh.

I filled in the complaints form on the dealership website at 8:55 AM and at 9 AM I got a phone call from a service technician apologising for not calling me back earlier in the week!

It's booked for Friday morning, and I'll just work from the dealership business centre while they look it over. He said no payment was required as it's "well within warranty".

 

I had the issue too , exactly like what you mentioned. Basically after changing the diff oil it went away.

 

I've been to Mercedes this morning so I thought I'd provide an update.

I got there first thing this morning and as they were quiet said I could take the car straight out for a drive with a service technician in the passenger seat. The noise is intermittent and only seems to occur under certain circumstances which meant it was ideal that I could drive it and try and replicate it as opposed to simply sending a technician out alone hoping they'd hear something.

We took the car out and did a series of pull-aways from a standstill and a crawl. Sods law I couldn't replicate the sound at first but after a few minutes, it happened a couple of times.

The service technician assured me it wasn't rear-diff related (and explained why) and said it was simply the exhaust/AMG Real Performance Sound "booming" under certain conditions (load, acceleration etc).

They offered to take the car into the workshop and check it over it I was still concerned but he was very friendly, non-pushy and was happy for me to take as long as I wanted to replicate the noise so I felt reassured it was nothing serious.

As I said previously, it's a very subtle noise, but once I'd heard it, I was always listening out for it. My wife can't hear it at all which demonstrates how subtle it is.

If it gets louder, worse or more frequent I'll take it back but for now, I'm not concerned.

 

The service technician assured me it wasn't rear-diff related (and explained why) and said it was simply the exhaust/AMG Real Performance Sound "booming" under certain conditions (load, acceleration etc).

I have my doubts with this explaination


I think if it were my car, I would disconnect the DSP Amp in the boot to see if the “performance exhaust” related sound that the technician suggested goes away. Maybe also the exhaust flap.

(But obviously I haven’t heard this noise of yours for myself so I’m just shooting in the dark!)


See post #25 onwards in this thread

https://www.aclassclub.co.uk/threads/fake-exhaust-noise-in-cabin.18821/

 

I had similar issue. For me it always made such sound when starting from standstill with wheels slightly turned left or right (ex. when entering roundabout) and with medium amount of acceleration. Just the sound, nothing more. During service I mentioned the issue. They've changed rear diff oil and it eliminated the issue for now. I had ~30kkm, 2022 model.

 

It's booked back in again for Thursday. I've also taken some screenshots of others comments and printed them out to take with me.

 

Good luck. Keep us updated.

 

I will. I've had to rebook for Friday 6th September so I won't provide an update until then.

 

Update time!

So I was back the my local MB service centre this morning as arranged. I dealt with two service employees so I'll refer to them as SE1 and SE2.

I arrived at 8.30 AM and spoke with SE1. He was VERY dismissive from the outset even though I was there two weeks prior and a service technician had been out in the car with me and heard the noise for himself. I informed SE1 that the noise was now more prominent, more frequent and that I'd done some research (thanks to you guys) and that there was a common theme of people reporting the same symptoms which went away after the rear-diff oil was changed.

I then informed him I'd be waiting and working out of their business centre which seemed to offend him for some bizarre reason and he was fairly insistent I go home and leave the car with them. I stood my ground and got my laptop out to work.

SE1 went away and came back an hour later asking more probing questions -

SE1 - "Does it only do it on full lock?"

Me - "No, it does it pulling away in a straight line or if the wheel is turned slightly."

SE1 - "I ask as you really shouldn't accelerate hard under full lock!" (He then proceeds to talk AT ME for about a minute about tyre skip and reversing on full lock which has nothing to do with the issue)

Me - "What are you talking about? You're the only one who mentioned "full lock" "

SE1 - "And this noise.. How do you describe it"

Me - "As I explained to you an hour ago when I arrived and as your service technician heard for himself. You could always speak with him?"

I then reiterated the research I'd done on here as well as the screenshots of other people having the same issue but he refused to look at them or engage with me instead telling me not to believe what I read on the internet.

At that point, he walked off and said he'd get the car looked at.

Three hours pass as I'm working but I occasionally check the MB app and I can see the car was taken on a test drive, then moved into the workshop for a couple of hours before another test drive.

At this point, I asked for an update from a different guy who walked past, SE2, who was much more pleasant and helpful.

To quote him -

SE2 - "We've taken advice from MB and flushed the rear-diff and changed the oil"

Me - "Oh great so there was an issue then? Did someone hear the noise on the test drive?"

SE2 - "I'm not sure about that but it's a "recognised issue" and MB has guidance on how we should fix it which is why we flushed the diff and changed the oil"

Me - "Ok that's great but any idea why your colleague insisted there was no issue?"

SE2 - "Erm......................"

Me - "Nevermind"

So there we have it. I was there almost 5 hours and had to stand my ground but it ultimately transpires that it's apparently a "recognised issue" with a MB-approved fix in place for it. Before I left I asked for some paperwork, or 'evidence' of what work was carried out to which they assured me they'd email me a copy. I'll chase this up next week if I don't have it by then.

I've only driven about 30 miles back home but there were plenty of opportunities to test and replicate the noise but so far - it's gone!

 

I would inform the MB UK ceo. Just cut and paste this largely and send it.

 

Couldn’t make it up, could you!

Well done on standing your ground. This really is not good customer service, Nevermind great customer service.

Definitely does not meet expectations.

If you do get a service report, please do share it on here as to the work done. 👍

 

If you do get a service report, please do share it on here as to the work done. 👍

I anticipated you asking me which is why I requested it from them

I'll keep pestering them until I get something.

 

By way of a quick update - I've done some more driving since, probably 100 miles over the weekend, and the noise hasn't returned so I think you can add me to the expanding list of people who have had this symptom(s) and it's gone away after having the diff oil changed.

Still no paperwork but I'll chase that mid-week.

 

Other A-Class models with 4 matic haven’t reported being so sensitive about diff oil change. I wonder why our model is. But it’s certainly worth remembering for the future.

 

Their system must have all the inventory details for ordering purposes. I wonder why they don't carry it across to the invoice.

 

Quite. Without the itemised bill, how would you know if they have replaced the non-reusable drain plugs (2j and the non-reusable fill plugs (2)?

Or if they have used the correct rear diff clutch pack oil in both sides….

It suggests obfuscation to me, especially when they list every last washer on a service invoice!


Don’t think it’s worth the hassle of pursuing it with them though, if the car still has warranty just keep an ear out for the noise again, or any other strange rear diff behaviour.

 

Morning xxxxxxx,

Thank you for your courtesy call yesterday and the subsequent copy of the sales invoice.

However, on viewing the invoice it is somewhat ambiguous and lacks the usual detail(s) I would expect. From past experience if this had been a service or paid repair, I would expect to see every last item listed on the invoice (to the last washer and ounce of screenwash - for example). However, the copy you sent me yesterday doesn't contain any specifics at all.

So that I can be satisfied that the "recognised concern" was correctly triaged and addressed do you have any documentation evidencing what work was actually carried out. For example, I'm aware that when changing the rear-diff oil (rear diff clutch pack oil) MercedesBenz mandates a specific oil grade and the replacement of non-reusable drain screws and fill screws.I have no 'evidence' this was carried out.

I appreciate the work was carried out under warranty, and as a result, I didn't have to pay anything, but I would still expect the paperwork to be of the same standards and level of detail as that of a paid service or paid repair.

As a result, could you please provide an itemised service report or sales invoice confirming the work carried out and an itemised list of the parts used please? This is extremely important for my records.

Many Thanks,

James

 

Very polite email. You'll probably get: "thank you for your feedback" 😂

 

Well done. 👍

Let’s see what excuse they come back with! 😂

 

Hello James, unfortunately as this is a warranty repair we are not aloud to give you the warranty invoice so that’s why I gave you what we had done which was the rear differential oil change.

The spelling error is on their side. I just copy/pasted it verbatim.

 

That's BS, they ought to have sent you the list of items and the work that was carried out in detail. When my rear pump failed in August 2021, they replaced it under warranty and here's what the invoice says, I'm gonna translate it for you (I'm only posting the code and description columns):

00541011 ........................ Quick check
00070641 ....................... Checked engine components based on fault code
00474100 ....................... Fuel tank removed and reinstalled
00475162 ....................... In-tank fuel pump replaced (after inspection)
A2474707800 ................ Fuel pump (genuine Daimler part)
A0259971845 ................ Fuel pump o-ring (genuine Daimler part)
EXL-00000011 ............... BP Ultimate 100 Active

The last item is the BP 100 RON fuel they put in the empty tank after it was cleaned and that's the only item I was charged for.

 

Part of me is tempted to drop it and move on - After all, there are better things in life to worry about.

That being said, given the less-than-stellar service I received at the dealership I contacted MB UK this morning and they agree that the document above is poor. They're picking up the baton on my behalf and will ask/instruct the dealership to provide me with a proper breakdown of the work carried out.

I don't anticipate an immediate resolution but at least I've had a moan and someone at MB UK appeared sympathetic to my cause.

 

Good work!

Lookers Group are sub-par in my experience so far, apart from a couple of individuals that I’ve known from the Drayton Group days - who go out of their way to provide excellent customer service.

PS. Is there an “AMG Pit Crew” number on a sticker on your driver door sill?

Apparently that’s a dedicated AMG customer service team you can call …..

 

PS. Is there an “AMG Pit Crew” number on a sticker on your driver door sill?

Apparently that’s a dedicated AMG customer service team you can call …..

Good question - My wife has the car at the moment but once she's home I can check.

 

 

Result!
That wasn’t so hard for them, was it!!! 😂

I don’t think it’s at all unreasonable to ask what they’ve done to your car, your property!

 

I don’t think it’s at all unreasonable to ask what they’ve done to your car, your property!

That's exactly how I phrased it to MBUK. It's my (somewhat expensive) property that a dealership has worked on. Regardless of whether it's a paid service, paid repair or warranty repair you'd expect the same level of treatment and the same documentation detailing what work they've done to your property.

It seems the penny finally dropped.