[126] Strong smell of fuel inside cabin and boot after full tank fill-up
 

A couple of days ago I decided to let my 500SEL stretch it’s legs a little, using it for normal daily driving. The car has been sitting in storage since June, and this season has only had very little use after winter hibernation, having been taken for it’s inspection, it’s annual service and a bit of school/office commuting in spring. It runs perfectly.

I filled the car up with petrol last night (realising that the previous visit at the petrol station took place in September… 2017:rolleyes5). This morning when I got into it, there was a very intense smell of petrol inside the cabin and in the boot (trunk), so I am (almost) certain the odour is coming from the fuel tank, presumably somewhere at the top of it. There was no smell of fuel before the fill-up, and nothing like this ever before (I have owned this particular car for nearly 13 years now).

Any thoughts on possible culprits?

Did fuel splash when you filled up? If so, I'd be looking at the filler neck seal. If it hardens or fails, when fuel splashes it goes right into the trunk.

Thanks for this suggestion - this does not seem to be the issue, though. There was no fuel splashing and the filler neck seal is fine.

Assuming you have looked underneath at your fuel cluster and all is well there, the logical next place to look is at your charcoal fumes canister and the associated hoses.