JBC400

My first MB after driving Audi's and Bimmers. Very different. Each has their merits.


Anyways, was wondering if engine noise is normal with this Bi-turbo.
It's hard to describe. When accelerating between 1500-2000RPM there's an audible rattling/clicking sound. Not a whizzing and not very loud. I am wondering if its the turbo. When the windows are down...can't hear it.


Any idea

rc400

What a coincidence, I was just thinking the exact same thing!

I changed my c300 for a new c400 which I picked up last Thursday.

I picked up the car with 18kms and now I have 350kms.

I have the exact same rattling sound between 1500-2000rpm.
i was thinking it's the turbos as well.
I don't remember hearing this sound when I test drove the a demo c400 at the dealer and it's something I surely would have noticed.

If I rev the engine while in neutral to approx 3000rpm, I hear the rattling slightly as the rpm is dropping back down.

I suspect it might be pinging a I wouldn't be surprised if they filled up the tank with regular gasoline instead of premium.

My brakes also squeak while coasting at very low speeds once they warm up without applying the brakes but then goes away when I depress the brake pedal.

I'm planning to go back to the dealer when I reach 1500kms if these noises still persist.

I'm hoping it'll settle during the break-in.

rc400

Anyone else experiencing the same engine noise on their C400?

W205C400

I've been experiencing the same noise. I've just past the 1500km mark and took it into the dealer and had someone ride with me. Was told that it's normal noise related to direct injection.

Very interested to hear if everyone is getting the same feedback.

W205C400

I've created a thread in the w205 forum as it seems to get more traffic. Here's the link: https://mbworld.org/forums/c-class-w...ml#post6538209

rc400

Thx for the reply! I'm starting to think that it's on only some c400s as it is a noticeable noise, if everyone's engine was making that noise then there would be more people discussing it...

heyjoe

My C400 suffers from the faint pinging noise described here and in the other thread.

My dealer duplicated it, consulted with MBUSA, and it was diagnosed as loose rods actuating the wastegates. Both turbos and both wastegates were replaced, but the noise, while less frequent, still exists. It may be octane related because it appears to come and go with different fill-ups. The dealer now states that the sound is part of the design of the turbo V6 and there is nothing that can be done.

It sounds like a very quiet type of detonation to me. I'm glad others have posted on this because I was starting to think I was the only one, and would get no further action.

rc400

Heyjoe, thanks for sharing the info!

It makes sense as it does sound like something is loose! Too bad they couldn't fix the issue.

jjjuun

Sorry for a two-year-after comment.
Has anyone of you diagnosed the issue of engine acceleration pinging noise at low RPM and also fixed the issue? I have been hearing it since I bought this pre-owned C400 last year, and eventually decided to figure out what the issue is, because the dealership here in Alberta said there was no sound when they put my vehicle in service last October. I hope the dealership/Mercedes Canada covers the cost of fixing this annoying issue. Thanks!

heyjoe

Hi jjuun,

Good thing this forum auto-forwards replies to old posts such as Hi jjjuun's. I was told the noise was wastegate rattle, and both turbos and wastegates were replaced under warranty after approval by MB Germany. When the identical noise resurfaced after the work was completed, the same dealer who had documented and confirmed the noise and made the repair claimed the noise was normal.

I retained a lemon law attorney and MB bought my C400 back at an extremely fair price and paid the attorney. I'm now driving a C43 coupe with no noise - it's a great, fast car.

john huh

I hear the same sound. Since I first bought it ! I took it to MERCEDES they told me it was completely normal!!?

BenzWay

Same here and I have a 2016 e400 with the knocking sounds at idle and rattling sound from the turbos when accelerating and dealer said completely normal