C220d knocking in cold - MBWorld.org Forums

Mar 8, 2023 | 09:45 AM

sc57rider

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Joined: Mar 2023

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W205

C220d knocking in cold

Hello
my 2014 c220d does this knocking sound ( see attachements ) when I first start it in the morning,
knocking goes stays when I accelerate and almost disappears after half hour of driving, car runs fine though.
any ideas ?

edit: new video added

Attached Files

IMG_2705.MOV (16.01 MB, 121 views)

Last edited by sc57rider; Mar 15, 2023 at 03:49 PM.

Mar 8, 2023 | 10:20 AM

Cosworth2000

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Joined: Jun 2012

Posts: 1,229

Likes: 188

From: Toronto

2022 E53 AMG

I can't hear anything. Is it coming from the inside of the car or outside of the car. Also, I only hear knocking when you move your phone.

Mar 8, 2023 | 10:25 AM

sc57rider

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W205

Quote:

Originally Posted by Cosworth2000

I can't hear anything. Is it coming from the inside of the car or outside of the car. Also, I only hear knocking when you move your phone.

you kinda have to put it closer to ear to hear it, it’s coming from the engine

Mar 8, 2023 | 10:38 AM

Cosworth2000

MBWorld Fanatic!

Joined: Jun 2012

Posts: 1,229

Likes: 188

From: Toronto

2022 E53 AMG

Since it's diesel, try some engine cleaner before your next oil change or if its under warranty take it back to MB.

Mar 8, 2023 | 11:51 AM

Keith66

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Joined: Oct 2018

Posts: 1,430

Likes: 820

From: Florida

2018 AMG E43

I've not listened to your file, but mine (M274 2.0 gas engine) has done what you described since I bought it 5 years ago. At first I thought it may be something wrong but I'm thinking it may be normal (?). At least on mine, if it was a problem, I would think something would've happened by now.

Good luck!

Mar 8, 2023 | 12:39 PM

sc57rider

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W205

Quote:

Originally Posted by Cosworth2000

Since it's diesel, try some engine cleaner before your next oil change or if its under warranty take it back to MB.

any suggestions please ?

Mar 15, 2023 | 03:48 PM

sc57rider

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Newbie

Joined: Mar 2023

Posts: 7

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W205

Quote:

Originally Posted by Cosworth2000

I can't hear anything. Is it coming from the inside of the car or outside of the car. Also, I only hear knocking when you move your phone.

I attached a new clear video sir

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Mar 17, 2023 | 05:15 AM

denis550

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Joined: Jul 2021

Posts: 15

Likes: 7

w211 07 200cdi, w212 12 220cdi, w205 15 220cdi

I assume your car has the OM651 diesel engine. It's really hard to tell from the video but I think my car has a similar noise. If the noise is coming from the passenger side in the engine bay, in the general area of the turbo and filter housing it could be the turbo bypass valve. The bypass valve is made from metal and if the spring in the part looses tension, it can develop a rattling sound.
Here is a Xentry Tips document describing the issue https://static.nhtsa.gov/odi/tsbs/20...19692-9999.pdf
And here are videos describing the issue:

Mercedes made a new part for the turbo air duct and bypass valve made of plastic which should solve the rattle. I also heard of people elongating the spring in the valve to fix the noise.
Again it's hard to tell from the video, it could also be the belt tensioner or the chain/chain tensioner or many other things.

EDIT: Here is a thread from the W212 forum with a similar issue: https://mbworld.org/forums/e-class-w...old-start.html

Last edited by denis550; Mar 17, 2023 at 05:20 AM. Reason: added link to w212 thread