faint knocking noise from the passenger side near fuel filler neck
Thread Starter
MBWorld Fanatic!
Joined: Mar 2004
Posts: 1,175
Likes: 24
From: Boston, MA
'14 ML350, '13 C220 CDI, '07 C280, '98 ML320
faint knocking noise from the passenger side near fuel filler neck
Hi,
On my '07 C280, when I don't have stereo on, I noticed a knocking noise coming from the passenger side rear (near fuel filler neck) area.
Symptoms:
- knock, pause of about 3 to 5 seconds, then knock, pause of 3 to 5 seconds, ...
- one knock at a time.
- this knocking noise ONLY is heard after the car comes to complete stop with brakes on. Again, the car is at 100% standstill.
- the sound is similar to tapping on the car body panel with back of the finger
I remember seeing another thread within the recent past regarding the similar issue. I am not able to find that thread.
Any one has any ideas where the noise is coming from?
On my '07 C280, when I don't have stereo on, I noticed a knocking noise coming from the passenger side rear (near fuel filler neck) area.
Symptoms:
- knock, pause of about 3 to 5 seconds, then knock, pause of 3 to 5 seconds, ...
- one knock at a time.
- this knocking noise ONLY is heard after the car comes to complete stop with brakes on. Again, the car is at 100% standstill.
- the sound is similar to tapping on the car body panel with back of the finger
I remember seeing another thread within the recent past regarding the similar issue. I am not able to find that thread.
Any one has any ideas where the noise is coming from?
Last edited by pcy; Nov 19, 2010 at 06:04 PM.
MBWorld Fanatic!
Joined: Jul 2008
Posts: 8,384
Likes: 800
2019 G70 6MT & 2022 Ford Maverick XL
That was my thread, I think. Mine sounds like I have someone trapped in the trunk. A few other people posted that their cars do the same thing and always have. I just laugh about it now when people are in the car and tell them I have my boyfriend locked in the trunk.
I think we decided it was fuel level sender units banging around in the tank, by the way.
I think we decided it was fuel level sender units banging around in the tank, by the way.
Super Moderator
Joined: Dec 2006
Posts: 2,403
Likes: 64
From: Camas, WA
2007 C230SS; 2014 ML350 BT
I remember Sanf had that problem on his 07 when he 1st got it. Don't think he got it resolved before he sold the car. Let me check my TSB's and see if I can find any info.
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MBWorld Fanatic!
Joined: Feb 2009
Posts: 5,537
Likes: 8
2006 C350 Sport 6MT
Hi,
On my '07 C280, when I don't have stereo on, I noticed a knocking noise coming from the passenger side rear (near fuel filler neck) area.
Symptoms:
- knock, pause of about 3 to 5 seconds, then knock, pause of 3 to 5 seconds, ...
- one knock at a time.
- this knocking noise ONLY is heard after the car comes to complete stop with brakes on. Again, the car is at 100% standstill.
- the sound is similar to tapping on the car body panel with back of the finger
I remember seeing another thread within the recent past regarding the similar issue. I am not able to find that thread.
Any one has any ideas where the noise is coming from?
On my '07 C280, when I don't have stereo on, I noticed a knocking noise coming from the passenger side rear (near fuel filler neck) area.
Symptoms:
- knock, pause of about 3 to 5 seconds, then knock, pause of 3 to 5 seconds, ...
- one knock at a time.
- this knocking noise ONLY is heard after the car comes to complete stop with brakes on. Again, the car is at 100% standstill.
- the sound is similar to tapping on the car body panel with back of the finger
I remember seeing another thread within the recent past regarding the similar issue. I am not able to find that thread.
Any one has any ideas where the noise is coming from?
MY STOCK EXHAUST HITTING THE BUMPER (VIBRATION). I USE TO HEAR THIS WHEN I CAME TO A RED LIGHT. IT WOULD BE WEIRD BECAUSE IT WOULD BE OFF AND ON. NOW WITH MY AFTERMARKET EXHAUST I HEAR IT MORE OFTEN.
Thread Starter
MBWorld Fanatic!
Joined: Mar 2004
Posts: 1,175
Likes: 24
From: Boston, MA
'14 ML350, '13 C220 CDI, '07 C280, '98 ML320
Karo, I can't see how exhaust can make that kind of noise. I checked under the car. Nothing on my exhaust system is loose. I am not saying your analysis is wrong... I am saying I don't see how exahaust can contribute to this noise...
On my car, the noise comes when I stop at a traffic light (after the car comes to a complete stop). No other exahust noises. Clean 'knock'... pause for about 3 seconds... then another 'knock'... another pause...
On my car, the noise comes when I stop at a traffic light (after the car comes to a complete stop). No other exahust noises. Clean 'knock'... pause for about 3 seconds... then another 'knock'... another pause...
MBWorld Fanatic!
Joined: Feb 2009
Posts: 5,537
Likes: 8
2006 C350 Sport 6MT
Karo, I can't see how exhaust can make that kind of noise. I checked under the car. Nothing on my exhaust system is loose. I am not saying your analysis is wrong... I am saying I don't see how exahaust can contribute to this noise...
On my car, the noise comes when I stop at a traffic light (after the car comes to a complete stop). No other exahust noises. Clean 'knock'... pause for about 3 seconds... then another 'knock'... another pause...
On my car, the noise comes when I stop at a traffic light (after the car comes to a complete stop). No other exahust noises. Clean 'knock'... pause for about 3 seconds... then another 'knock'... another pause...
Junior Member
Joined: Sep 2010
Posts: 33
Likes: 0
From: sept-iles, quebec, canada
C280 2007 4matic
on my c280 2007 4 matic ... i have the same noise, it is the same sound as door locking inside the rear door. my car have 72 000 km now and the sound come only after stopping and hold on brakes, it dont come if i put tranny in neutral.
Yvan
Yvan
MBWorld Fanatic!
Joined: Feb 2009
Posts: 5,537
Likes: 8
2006 C350 Sport 6MT
Mine for sure is that.
Newbie
Joined: Nov 2010
Posts: 1
Likes: 0
C230WZ
I had the exact same sound happen to my 2007 C230WZ. When I took my car in to get serviced, I asked about that noise. I went on a test drive with a mechanic who's been servicing Benz's for 30 years, and he mentioned that this is very common. It's the fueling system, something about a process needed to release some type of vapors (as you can tell, it was very technical, I don't fully remember every detail). The process/cycle only occurs when you are at a complete stop. However, you must be stopped for atleast 10 seconds for the process to fully finish. If you accelerate before 10 seconds, then the process restarts the next time you stop.
I hope that helps clear things up. There's nothing that can be done to prevent that. They have been working on fixing it for newer models.
I hope that helps clear things up. There's nothing that can be done to prevent that. They have been working on fixing it for newer models.
