Ciprian Costa

My car makes a horrible sound arround 1000-1200 rpm, it does not matter if the car is in D,N or P,also when the sound is being made,the floor vibrates. I have captured the sound on video Any idea?

chassis

Is the vehicle in warranty? If yes, take it to the dealer.

Ciprian Costa

no,it is not in warranty

SCRL

Does it do this when the engine is cold, or only when it’s warm?

i have a 220d which is distinctly noisier when fully warmed up versus when it’s cold. When it’s cold it’s creamy smooth and quiet. When it’s warm it’s much more “diesel-ey”. For me this happens on a light throttle (such as when just starting off), at just about the rev range you’re talking about. It’s not there at highway speeds or on harder acceleration.

Dealers don’t seem to think it’s a problem, and I’ve not pushed the point because I’m not sure myself.

Ciprian Costa

It makes this sound all the time,it doesn't matter if the engine is cold or warm

SCRL

Hmmm... OK. Well, I must say that it does sound similar to what I'm experiencing. Mine is perhaps not nearly as bad, but it's that same "motorcycle overtaking me" sort of noise.

Maybe a garage can identify it for you, and I'd be really interested to know what the outcome is....

SCRL

Did you find out what was causing this?

chassis

Nearly 100% sure this is an exhaust component contacting the vehicle body or another adjacent component. Could be a bent exhaust or a failed exhaust hanger/mount. Did the noise start recently? Has it made the noise during your entire ownership?

Ciprian Costa

The noise started afther a long road trip of 1200km. At start i did not hear it so often, twice a week maibe,and not so loud. This was about a year ago, now the sound is more louder,and i hear it every time,no exception,it does not matter if the car is moving or not,if it is in P,D or N,every time the limitter is at 1000-1200 rpm it starts rattling,the floor also vibrates like something is hiting the frame,but the sound is present only inside the car,the mecanic can't find where the sound is comming from.

Ciprian Costa

no,it still makes the same noise

chassis

Exhaust.

Did you contact the exhaust with the ground or an object? For example, did you run over a curb, a trash can, a bicycle, a rock, a rail/train crossing, or anything that could bend the exhaust?

On a new vehicle like yours, it is unusual for this sound to occur.

How many drivers use this vehicle? You? Your spouse/partner? Your children?

Ciprian Costa

Underneath the floor the car looks like new. The mecanic lifted the car on the elevator,removed the plastic shields but the sound is not present at the exterior of the car. I am the only driver of the car,and i defenetly did not damaged the floor in any way. To me,the sound is like metal hiting the frame of the car.

parkwood

I have a 220d and there is a resonante sound under acceleration in a rev band in mine also but i think it eases as the car warms up. I noticed it on day 1. I assume it is some sort of resonance within the exhaust system itself ie the way the gases are circulating as it reminds me of my old basic cars of the pastcwhich could present the same type of noise. It is insufficient a problem for me to be concerned but i would prefer if it was not present but i rarely notice it these days.
So it seems to be something inherent to the 220d design.

Ciprian Costa

Any ideas guys? My car still makes the same rattle 60k km with this horrible sound!!!

mercedes.fan

What does the dealer say then? Just looking at the undercarriage and stating that an almost new car looks new underneath is not much for diagnosing

parkwood

Mine is not as heavy a sound as yours and is something i am sure could be heard in previous older cars. To me it sounds like an exhaust gas circulating sound and happens when the engine is under load. It is summer here and i have not noticed it for awhile. I will try to listen out for it.

Is your diesel good quality? Have you tried a premium product to see if it makes any difference...i always just use the supermarket normal brand as thats the most readily available and much cheaper than traditional garage forecourts here.

Ciprian Costa

Finnaly fixed it. There are 2 fuel lines under the floor that rattled at low rpm. Some zipties fix it.it took 50k km to find the issus.

rox

Hey there, would you please share some photos of your fix. Thanks

Ciprian Costa

Don't have pictures,exactly under the driver's floor ,remove the plastic shield and there are 2 metal fuel lines that hit's the floor when the engine is under load at 1200rpm. The fuel lines are fixed with some plastic bracket's to the floor of the car but the bracket's aren't effective.just tighten the two fuel lines with zip ties and magicaly the rattle stops. It drived me crazy for 2 years and 50k km...

nori76

Do you rememberdo you still remember, did you tie the two fuel lines together, or did you tie each line separately with something?

Ciprian Costa

Yes,i tied them together,no problems from that point

nori76

maybe you can tell if you caught the wires when they are coming down or when they are running horizontally? was it enough to catch the wires in one place only? Did they hit the car floor, causing it to buzz? was it enough to remove only one plastic bottom cover to catch the wires at this length? personally I caught these wires with a band and it is better, but I still hear this buzzing, maybe I caught them not in the place where it belonged.

Ciprian Costa

I zip tied them horizontaly together to create tension betwen them in only one point

nori76

Thx, i will tried more...

nori76

today I went under the car again. I did as in the video and .... for now, divine silence, no vibrations, let it be ...