Fuel smell from engine bay
I'm pretty sure that fuel smell is coming from the hose area as marked in the attached photo.
Started after taking the car to MB dealership to inspect rough idle issue recently.
As you can see in the photo, they must have wrapped the hose with some tape as I can feel
that the hose is broken under the tape at that spot. If I approach them, their work against
mine, so no win there.
Would anybody please know the part number of that hose please?
2010 W212 E250 CGI
Engine:M271
Thanks
Milo




Hi Thefisch,
The smell is coming from either that hose or the part that sits above it (cylindrical metal part).
I had a more precise sniff around and can confidently say that the smell is
coming from the wrap (black tape). It smells very much like petrol!!!
Either way, the tape is the culprit!
I know for sure that MB service broke it and wrapped it without telling me
about it, but I have no proof now. All I know is that the smell started from
the day I took it to them for service. Initially I thought that they might have
spilt something in the engine bay so the liquid might be evaporating, but not
quite.
Taking it to another MB service on Monday as the car is under warranty.
I'll let you know how I go.
Thanks
Milo
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was still present. Took it to the dealership again. This time they found that the smell was coming from the engine oil which was contaminated by petrol which seeped into the oil
while the thermostat was faulty few months ago. They replaced the oil and oil filter. Got home, had a sniff around the engine bay and the smell was gone!
A day or two later noticed the smell of petrol again. The smell is coming from the same area (as marked with red circle in the photo). I have clamped the little breather hose to
ensure that the smell is not coming from either end of the hose (as marked in green colour). It still is.
I told the guys at the dealership that I would park the car in the middle of the Sydney Harbour Bridge and torch it if the issue continues. As if they care...

The car is under warranty, so I have a feeling that they are not that keen to spend money on fixing it.
I'm starting to think that I'm imagining things or even that the smell is normal, but I think it's not. When I smell the area (circled in red), I can smell petrol.
Could I please ask a few of you E250 CGI owners to have a sniff in the area (circled in red) on your engine while it is warm and tell me whether it smells of petrol?
Please. This is driving me crazy.
Thanks
Milo
Last edited by Milor; Aug 22, 2017 at 07:37 AM. Reason: add photo
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I would also urge you to not use screw clamps on hose as they will cut into the hose. Recommend what is commonly refererred to as fuel injection style clamps that have an internal band to protect the hose when the band is tightened.
So, just in case it's happening to you, pay attention to the hose!
Thanks!
Milo




So, just in case it's happening to you, pay attention to the hose!
Thanks!
Milo
Gasoline smell under the hood should not happen and if it does it is very alarming. The fuel is pumped in the engine and dosed by the injectors either in the intake air flow or directly insid the combustion cylinder. There should not be any way for the gasolne to leak out to be smelled. Even if the engine runs rich the fumes should come out from the tail pipe like it is during cold weather start. With hot engine some exhaust gases are recirculated back to the intake side but again this is under vacuum and no gasoline smell under the hood should be present.
I would be very cardfully checking the fuel rail and connections to injectors for leaks as it should be about the only way gasoline can get under the hood outside the engine.
So, just in case it's happening to you, pay attention to the hose!
Thanks!
Milo
It has been more than a year since they replaced the hose (and associated / attached piping), but the smell is still coming from the hose marked in red in the attached photo.
The actual material (rubber the hose is made from) smells when the engine is warmed up. The hose heats up and then it smells. It even smells while cold, but a lot less.
Took the car back to Mercedes to complain about the smell, but now they tell me that the hose in question smells like that on all 1.8 Turbo W212's. That is impossible, as I know
that it didn't smell when I first bought the car.
Could one or more of you please check whether that hose smells once heated up on your 1.8 Turbo, please?
Many thanks!
Milo
It has been more than a year since they replaced the hose (and associated / attached piping), but the smell is still coming from the hose marked in red in the attached photo.
The actual material (rubber the hose is made from) smells when the engine is warmed up. The hose heats up and then it smells. It even smells while cold, but a lot less.
Took the car back to Mercedes to complain about the smell, but now they tell me that the hose in question smells like that on all 1.8 Turbo W212's. That is impossible, as I know
that it didn't smell when I first bought the car.
Could one or more of you please check whether that hose smells once heated up on your 1.8 Turbo, please?
Many thanks!
Milo
Thanks
Milo
It has been more than a year since they replaced the hose (and associated / attached piping), but the smell is still coming from the hose marked in red in the attached photo.
The actual material (rubber the hose is made from) smells when the engine is warmed up. The hose heats up and then it smells. It even smells while cold, but a lot less.
Took the car back to Mercedes to complain about the smell, but now they tell me that the hose in question smells like that on all 1.8 Turbo W212's. That is impossible, as I know
that it didn't smell when I first bought the car.
Could one or more of you please check whether that hose smells once heated up on your 1.8 Turbo, please?
I have the same problem whit my C180 CGI hand switched 2010 m271 Evo 115Kw (157) horsepower. i have fuel leaking from that rubber. On the highway he give me a fuel consumption about 9.2L/100 KM its to high 59 liters benzintank i can do 490 KM whit 1 tank




