- Mercedes-Benz C-Class and AMG: Why Does My Car Smell Like Fuel?
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start to smell fuel when car idles for to long, inside and outside. cls55
This is another case where it is unbelievable why Mercedes Benz would allow a potential issue of leaking fuel pumps in their cars to continue, without having a recall and inspection or refit to a superseded design. Does somebodies house or family need to be harmed before they get off their asses. Just where is the Transportation Safety Board on this issue???
What ever the issue, leave the car outside until the issue is found and repaired.
A quick check under the hood should give you an indication if that is where the smell is, or remove back seat and check the pumps for leakage.
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seriously was not expecting all these issues a month and half into owner ship of such an expensive car.


So monday i started to smell fuel again, checked under the rear seat and it looks dry on both sides. Its not coming from the exhaust.
Ive noticed that the lower my fuel level goes the stronger and more frequent the smell gets, it seeps into the cabin as well as smells on the out side.
it seems like the smell is coming from the engine bay area but its not consistent , its on and off , as in comes in waves its weird. The strongest smell seems from the passenger side but who the hell knows at this point.
The thing that is weird is that it doesnt smell like fresh gas or like the scent you pick up from the gas station. its smells old, like real old and very pungent.
Seems like this fuel smell issue started after my car told me to tighten my gas cap and threw a p0505 https://mbworld.org/forums/w211-amg/...reset-wtf.html
I have no CEL but will hook up my scanner and see if anything is pending. Car seems to be driving fine but does seem like the idle is a little lumpy, and at wot doesnt seems as smooth, and power doesnt seem to be as aggressive, as it was when i first bought it. But i could just be over analyzing.
Car is bone stock other than putting in the the k&n drop ins.
so what do you guys think? evap tank, injector, regulator, un burned fuel?

NO CEL, no pending codes, no fuel on or around either sending units, or fuel tank.
can someone point out to me where the fuel related parts are in the engine bay so i can look. like evap tank location, regulator, etc.

https://mbworld.org/forums/w211-amg/...-gas-tank.html
could be where the evap hose comes off the tank
also check the O-ring on the pressure dampener on the fuel rail
these are all spots i have gone through on mine.
Last edited by zombiescustoms; Dec 4, 2013 at 01:18 PM.
i put the car into my shop closed the doors, hooked up pipes to my exhaust and ran them out side, let the car run for 10 minutes and there is zero smell of fuel. which for the last few days with a few bars of fuel i would come out side and you could definitely smell fuel. I am seriously stumped.
Only thing i can think of that is different from the other days is that i went to lunch today and my car was not on an ice cold motor. but realistically even when i went to lowes on my way home from work last night, started the car and again was able to smell fuel.
ever since ive filled up this morning the car stops having its fuel smell. seems like once the fuel starts to go down thats when the smell reappears.
Any other thoughts?
I also removed the rear seat cushions and panels to see if i could find something . there is almost no scent at all, looks like someone has been under there before as well and replaced both units as they look brand new, and have a missing screw on each panel.







