029405

Hello Everyone,

I have a 2012 E350, currently at 133,xxx miles. I filled up the tank last week on Thursday, the fuel pump kept going to the point where gasoline overflowed and left a small puddle of gas on the asphalt at the station. Immediately I got in the car and could smell gasoline, I assumed it possibly was either my shoes or the fact that my fuel tank overfilled. Heavy rain was constant that day so I didn't air out the car until this past Saturday.

I read some W212's have an issue with a specific part underneath the rear seat on the passenger side that can crack and from that overfilling, or even topping off the fuel tank can cause gasoline to enter the cabin of the car. I removed the back seat and checked the part, it's really dusty but i didn't see any cracks or gasoline however that side did have tons of dirt and residue compared to the opposite side (see attached photos).

I wanted to know if I should change this part or could the smell of gasoline be coming from somewhere else. I did want to mention my car isn't garage kept, when walking to my car (including the rear passenger side) I don't smell gasoline but when I get in my car the entire interior smells like gasoline whether the car is started or not. Should I begin by replacing the part in the photos before I take the car to the shop, I saw some youtube videos and it seems very straightforward. Any other advice would be greatly appreciated, thank you all so much!




Visually inspected and didn't see any cracks:


Apologies for the bad angle, this is the padding below the rear seat, I can see traces of something was absorbed, could it be gasoline?




Here is the rear passenger side, much more dust/grime, did a close visual inspection and noticed the dark areas had a shine to them:



Here is the rear driver side, no dust or dirt, much cleaner:


Another angle showing the lower part of the padding - in much cleaner condition than the rear passenger side:

juanmor40

Unscrew the black cover plate and check the pump below. There should have been 2 cover plate: passenger and driver side

029405

Thanks for the response! I unscrewed the blacck cover plate for the rear passenger side and checked the pump, I think the photos I uploaded may not be showing.

029405

Yes this is the exact video I watched, followed all the steps and once I got to the pump that was replaced in the video I didn't see any signs of cracks but around the area there was lots of residue compared to the opposite side pump. Do you reccomend I replace the rear passenger side one even though visually it looks fine? Maybe because of all the dust I didn't see any cracks or damage.

juanmor40

Is the tank still full? Or below 3/4?

The real test is to top it off, and if there is no leak, you are on the clear. However, if it leaks, you need to empty it quite a bit before opening to replace the pumps. It can flood the cabin if already full

029405

The Tank is still above 3/4 full, would you just drive around until the tank is down to below 25% ? Or manually remove gasoline from the fuel tank?

pierrejoliat

I would drive it to reduce the gas volume, if you open the trunk does it smell? I don't see any sign of gas in the car, but there are trunk vents close to the charcoal canister below the fill neck,

029405

Got it will do, thank you and yes the trunk smells as well.

S-Prihadi

REAR SEAT :
Left side of car is FUEL FILTER
Right side of car is FUEL PUMP

I don't see you opened up the black metal round cover and take photo of fuel filter.
I hope your fuel filter overall possible leak points are the same as mine , albeit the locking plate is different.




Because these 2 components below uses o-ring, that is a leak suspect






Zoomed










When you overfilled your fuel tank till it spills out of tank filler mouth, very likely your activated charcoal canister is already soaked with LIQUID fuel.
It could go bad soon, do watch out. It is designed to hold gasoline fume, not liquid gasoline. It can then be the source of fuel smell, but not likely too strong a smell in interior.
I had one un-lucky incident of such overfilled from a failed fuel dispenser vapor sensor , but at that time I was on a super long trip and probably that is how the liquid fuel in the canister
was eventually fast dried from suction of the fuel vapor system. Also mine is the simple version not like USA version with lots of sensors... so mine is more STUPID version if not CRUDE version where the canister
has no sensor at all. US is very strict on fuel vapor releasing to the atmosphere, not for my country

pierrejoliat

A similar situation happens to me in New Jersey, it is full serve only there, My car smelled in the cabin and especially in the trunk, I do have a ski pass through behind the armrest and folding seats, I drove the car for a day and left the windows and the trunk open overnight for three nights in the garage at my sons house, smell finally went away, I also sprayed washer fluid down the drain hole in the front lower right corner of the gas door recess, seemed to help somewhat.