chrissy

it is annoying isn't it. i can't see how it's the Bose cause I don't have Bose in my car but that lovely noise is still there. Hopefully someone will get it figured out so we know what the hell it is. Good luck

levelr123g

it is the gas sloshing around in the tank. the car only does this after you come to a stop. it is not bose amp as it does it whether the radio is on or off.

chrissy

is there something the dealer can do to fit it? it sounds like a knocking noise and it's annoying and definately should not be there.

mctwin2kman

Mine makes a slght popping sound for a few seconds when stopped. It is very light and I have heard it when my wife parks in the garage and I am in there as well. It was the exhaust backpressure pop sound that is common on a turbo or supercharged car when warm that I heard. I do not know if this is the same sound but when at idle these supercharged cars will make a slight popping due to the backpressure in the exhaust system, or maybe the lack of pressure. I am not sure why this happens I have just heard it on the forced induction vehicles I have driven. Happens when you rev the engine a touch and then let off the gas. Other than that I did have a rattle in the rear end that was ESP related and I thought was the rear sway bushings. My dealer checks the rear sways and told me that the updated bushing was on there already and blamed the ESP since it was during spirited(rear end sliding) driving or over washboard type road surfaces. I had the ESP disabled but as we all know that does not truly disable the system.

DCXdynodog

What you are describing (when you let off the gas) is caused by leaks in the exhaust system and it doesn't know if it is naturally aspirated or not.

levelr123g

the car only does it after you come to a stop, not while moving. possibly its the evap system.

mctwin2kman

So every car I have driven has had leaks in the exhaust on a forced induction car? I am just curious because that can't be a good thing to spend all this money on a car and have an exhaust leak from the factory. I am really curious now if this is supposed to happen or if I just keep driving Turboed or Supercharged vehicles with exhaust leaks. If so MB, Dodge and Ford need to fix the darn exhaust systems.

CSportAnt

Me too!! i have that some sound coming out from the trunk area when stopped. And I do not have the Bose system. Sounds like someone is in the trunk knocking. I have the C230 Sport Sedan, got it like a month ago.

levelr123g

it has nothing to do with the supercharged engine as i do not have a supercharged engine and i get the same sound. i really notice it when the tank has less then a 1/4 tank of gas in it.

czachari

I did some spirited driving then pulled in my driveway, quickly got out of my car and basically lied down under the muffler area to see where the sound was coming from. It's not as audible from below the car. he trunk space must be amplifying it. Anyway, the sound seems not to come from the muffler area. It's further towards the front most likely where the rear suspension or even further towards where the rear passenger seat is. To me it sounded like metal contracting as it's cooling off and that must cause something else to make the noise. This will be hard to pinpoint sine it only happens when stopped and after spirited driving.


CZ

czachari

Dealer says noise is "normal" for C-Class. Something about the 2 fuel pumps. I said "bullsh_t!". Why is it only doing it when it's hot out and the car has been run hard? Why is it only doing it when the car is stationary? I am not taking the car back unless they fix it...


CZ

preyx

Yeah, just leave the car there until they've 100% confirmed no more problem. That's what warranties are for.

coconutpolito

Same problem here guys. I have an appointment with my dealer on Monday and will let them know what's going on and I'll post what they tell me. Wish me luck!!!!

Brunelleschi

Let the girl out of the trunk and the thumping should stop

Saprissa

Sounds to me you're having the same problem plaguin Fords & Chevy's.
Check out this link to the strange sounds coming from the trunk.
Trunk Accessory
This red-button in-dash feature should be installed on MB's too !

Mr.Ed

that's just hilarious. Well made ads too, for a local dealership!

TNblkc230wz

Check the rear swaybar end link bolts. Mine made a similar poping noise when i first installed the C32 Sway bars and didn't have the end link bolts tight enough. The bolts work ever so slightly lose and started making the noise again until I retightened them. It would make the noise with the car parked and turned off for a couple minutes.

Outland

Nuk,

Did you ever get this figured out? Ive got a noise coming from the back that sounds like the right rear axle or something in the area. Its been getting louder...used to be I could hear it only with the windows up and the radio off when you let off the gas. Now its noticeable with the windows down and when the gas is pressed lightly. Sounds like a bad bearing, or a gerotor noise...can't describe it very well. I just know something is up. Ive been to the dealer, and the car is quiet when they drive it. It happened to me to, when I had the tech in the car, the noise was not there. A few days later, its back and louder.

ffejalink

I get the same thing. It's close to a "thump thump thump." I usually only hear it when the radio is off, windows up, etc, when coming to a stop (or already stopped). It's never been enough of a nuissance to have the dealer look at it. Sounds like it wouldn't be worth it anyway. Keep us updated if you find a fix.

CclassRun

i have also experienced this noise. I always assumed that it was gas sloshing around in the tank. this seems like a reasonable explanation doesn't it? w203 are infamous for sloshy gas tanks yes??

blkc230k

mines an 05 c230k auto
and i can hear that "put...put" noise, it bugs me at first, but now i always have my music on, so doesnt matter no more..
im pretty sure its the exhaust backfiring...

Narcissus

Lift the car from the back and bring it back down, if the thumping stops for a few days then it's your spindle bushings, seems to be quite frequent on c and e classes.

CarlsbadKmprssr

I also have this noise. It sounds to me like its coming from the tailpipe and is in time with the engine. I would pretty much rule out gas sloshing around since it often happens after the car has been completely stopped for more than a minute, which I think is more than enough time for the gas to settle a bit.

BorisTheSpider

I have an '05 C230K SS, I noted this issue and took it in for service.

I was told that the problem I'm noting is actually a noisy purge canister. This can not be 'fixed' in our vehicles (some models they added a restrictor to quiet the noise). I was shown, the actuator is located on the driver side under the hood near the ABS on the sidewall. The purge canister is located in the rear wheel well and this is why is sounds like an ESP/ABS/Brake issue.

Can anyone confirm this? I can not check the canister at the time of the noise as it occurs when driving.