Acceleration Noise please help

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Rubb3rduck3d

New Member
Joined
May 6, 2020
Messages
15
Location
Orpington
Car
W205 c220d
Hi all,

need some help if possible! Been going mad trying to figure this one out....

Car has developed a low Pitched rattling/grating noise at around the 2k/2500k Rpm mark, it’s in all gears and distinctively louder when applying the gas!

I have exhausted all options, I’ve taken it to 3 Indys & 1 specialist, who each tell me it’s fine and that the exhaust system, drive train & turbo are solid, there are no EML lights or noticeable loss of power... But there is something defiantly off, it just sound course and rough, when the week before it was absolute sound!

ive Been under the car, check the planges, gaskets @ heat shields, even gave an early service In case there was gunk or **** build up.
I’ve pulled back the carpets and checked all the footwell seals and plugs.....

It a w205 c220d with 30k on the clock.....(64plate) I’m at a loss and it driving me made trying to locate this mystery noise, its coming from the driver side footwell and Only noticeable in the cabin.... I’ll share link to the driving noise, So you can here the raspy metallic noise..... I’ve scoured the net for answers and hoping you might be able to help me, is this fairly common in these cars as it’s darn right disheartening as I love it but become increasingly Concerned.

I know I’m not going mad! It’s definitely sound more exhausty

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It sound like some sound deadening has become dislodged.

TBH with you that engine in the 205 is not quiet at all. One of the lads I work with has one and he always moans about the engine noise.
 
He replied saying he has the same noise. He has checked everything on his car and has concluded its sound deadening thats moved or the lower boot at the end of the column that has come loose.
 
Thanks for looking into that for me with your friend, sorry to hear his surfing the same blight! I’ll pull out the footwell again and see if there is something I overlooked, hoping that’s the case! Did it resolve it for him?
 
Hi and welcome.

How long have you had this car and how many miles have you put on it since you bought it ? , when did the noise start ?
Thanks Pete,

I’ve owned the car around 7 months now, so just out of 6 months warranty. it started very noticeably around 1 month ago, it’s only got 30k on the clock and the noise came about after i filled up at shell that month.
Cheers Ben
 
Thanks Pete,

I’ve owned the car around 7 months now, so just out of 6 months warranty. it started very noticeably around 1 month ago, it’s only got 30k on the clock and the noise came about after i filled up at shell that month.
Cheers Ben
Got the covers off the engine today, is this a normal sound?
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No. There is a low frequency irregaulare thump from somewhere.
Is the aux belt running smoothly ? Alternator pully clutch ?
 
No. There is a low frequency irregaulare thump from somewhere.
Is the aux belt running smoothly ? Alternator pully clutch ?
That thump is just the air intake without the box on :) the belt to me seems fine!? It’s running quite smoothly
 
On an earlier suggestion which prompt me to pull out the carpet and check all the seals and plugs. annoyingly they were all solid and firmly in place which leads me to believe it’s something defiantly mechanical 😟 pics attached if they help anyone
 

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Update, issue identified - had the car diagnosed with via STAR - no codes or issues found.
The noise in question is generated by the bypass valve in the stage2 turbo housing. The metal valve rattles against the aluminum housing and vibrates when under boost causing the grindy metallic noise, it’s only noticeable really to the driver.

mercedes fix to this is to replace the turbo housing with new one which has a plastic valve. It’s prevalent on the om651 engine and rectified in the new builds.

New housing costs £500+ plus Labour and vat makes it £1000 approx job. (No thanks!)

it’s not critical to the cars running, just an annoyance and common on the gen1 w205 models and previous w204. (attached) is a user case example with part numbers
 

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the rattling sound during acceleration is caused by a loose bracket on the exhaust system,or a small exhaust manifold leak
 
the rattling sound during acceleration is caused by a loose bracket on the exhaust system,or a small exhaust manifold leak
Thanks Sheryllee, is this something you have had diagnosed/fixed?
 
Fix found! Replaced to day and noise is gone.
 

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Hi, was the noise you were experiencing the same as here?
Ringing noise
A more clear video on this topic highlighting the noise on my car:
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