Mladen_bg

Hi guys,

I own CLS 350 D 4matic, generation 2018. The car is in a perfect state but there is one weird thing. When I drive it easily and when RPMs reach 1500 value there is some weird noice that I hear. Here is a link for the video that I recorded and on 10th second of the video you can clearly hear what I mean

https://youtu.be/jBNWMDNLeU8


This is only happening when I drive. When I press the pedal in the neutral gear and reach the same RPMs, there is no that noice. Does anybody have idea what this can be?

Thanks

W205C43PFL

I don't hear anything abnormal but just in case I would need to play the same video on a different device in case my speaker isn't playing certain sounds, If you are talking about the whistle noise, that is your turbo. Normal.

Mladen_bg

Thank you for the feedback! So just to check one thing regarding the whistle noise that you are mentioning. Are you hearing that exactly on the 10th second of the video? If you do, then we are talking about the same thing beacuse the noice that I am talking about starts exactly at 10th second.

W205C43PFL

I played the same video on a different device and I still don't hear anything abnormal or I am not hearing what you are hearing. Are you able to record another video, is it louder with windows opened?

Mladen_bg

Hmm actually this is the most representative video that I was able to record Ok let me ask a question this way. Normal or abnormal, do you hear anything different from the 10th second of the video that you didn't hear in the first 9 seconds? Or for you on your devices it's just same kind of sound in the first 9 seconds and from the 10th second. Let's say it's normal. But is it different kind of sound from the 10th second for you?

W205C43PFL

I couldn't hear anything out of the ordinary. I played the video on a phone, a computer and a television. It is louder starting from the 10th second and beyond but that is it.

It does sound artificial though and if I recalled correctly, MB have synthetic engine sound for certain models in the E-Class and CLS range of vehicles, not all though. To confirm if it is in fact pumped in audio, you need someone to listen to the speakers from both the front and rear seats. Alternatively if you have code B63 when you ordered the vehicle, you might have synthetic engine sound.

Does it sound different when you switch the drive mode, so comfort, eco, sport, sport+ for example? When you notice the sounds, does the vehicle stutter (at least I don't see that in the video so I assume it is a no)?

May I ask why do you think something is wrong? Did you just notice it sounding different recently or that you got this as a used vehicle and were curious? If this is a new vehicle, keep in mind as the engine runs in during break-in sounds do change. The outside temperature as well as the current operating fluid temperatures also can affect the engine.

Mladen_bg

It might be but to be hones this doesn't sound to me like the fancy artificial synthetic sound. It's more like some small detail is causing the unwanted vibrations or some scraping sound between 1500 and 1750 RPM.

Not really. The pattern repeats in any driving mode and it only depends on RPM. It starts at 1500 and it lasts until 1750 and then it disappears. It's only between 1500 and 1750. Never below 1500. Never above 1750. And let's say that I notice this from the 4th gear and above.

No. The vehicle behaves just fine. If I play the music on the speakers I would never notice anything weird during the drive.

Well it's just sound between the 1500 RPM and 1750 RPM that I found weird. There is nothing else related to the vehicle that I would call wrong.

It's the second case

In the end let me ask this. You mentioned turbo. Is there some relations between the 1500-1750 RPM range and activating the turbo on 350 D?

W205C43PFL

First of all, congrats on your vehicle purchase and I am sorry to hear about the issues you are facing with it.

Thanks for breaking down the questions in parts and then answering the questions in each individual quote : ) I just realized how cluttered my reply was and I am sorry about that. : (

As for the last question, yes I do hear turbo whistle shortly after the start of the video. Most MB models speeds up the turbo at that range, after all, you need to have exhaust gases to spin the turbo but it still does vary depending on engine size.

As for the scrapping sound, I am sorry in advance but I really don't hear it, maybe I could try listening to it tomorrow again on yet another device or better yet hopefully someone else chimes in since so far I am not able to help you out, sorry about that : (

Since I couldn't hear it personally but from your description it could be different things, since you mentioned it doesn't happen when you are just free revving and not in drive (as you mentioned in the original post), it could be the transmission that is causing the sound since it is disconnected from the engine if you are in neutral but I highly doubt anything is wrong with your transmission as transmissions are very robust. There is also a reason why they has a lower service frequency compared to the annual requirement of an internal combustion engine.

How many miles or kilometers does your vehicle have?
Was there documented transmission service records before you purchased the vehicle?
It could also be your brakes, if it is a grinding sound then it is highly likely the brakes, could be pebble stuck in the rotors so it could happen even when you are not braking.

Mladen_bg

The patience and the effort that you put in this conversation is extraordinary and I am very grateful for that! Absolutely no need to say sorry!

Thank you and it can actually be the case that I've actually just bought the great car and now I am obsessed with everything Even with the issues that maybe exist only in my imagination

It has 90 thousand kilometers. It is bought from the official dealer as a used vehicle and it has the complete official maintenance history. Beside the regular maintenance there was only the water pump change and that's it. When I bought it I did the regular maintenance of the automatic transmission as well as the oil and filters change. My mechanic says that the vehicle is in a perfect state so maybe it's just my obsession with the details, even those that are normal And I will suppose that it is the case because my mechanic says that it is normal, you are saying that it is normal so I'll just continue to enjoy driving it.

W205C43PFL

Thank you for your update on this, I am glad to hear that there are no issues with your vehicle! Enjoy it!