I'm currently chasing down the fuel smell in my XJS - the previous owner mentioned he had the tank swapped, so I thought a load of fuel might have spilt out & soaked all the sound deadening/insulation.

Does anyone know what is behind this yellow foam panel which sits behind the rear seat backrest? Is it a solid metal panel separating the passenger compartment from the fuel tank? I want to know if I should bother removing it - those black marks near the center feel/smell like old fuel whch looks like it has seeped trough from behind? & there are various marks which look like old fuel which has varnished.



The rusty patches in the seat squab were caused by what I think are old bits of rusted MIG welding wire which have been sat there years trapped under the sound deadening so luckily it looks to be only surface rust & should clean up - thanks previous owners

 

Are you sure that it is coming from the rear end; you may have an under bonnet leak?

 

There is a steel panel as such.

It has holes in it for wiring looms, with plugs/grommets of course.

The "lip" of the fuel tank that usually leaks is right there in that lower seam created by the boot floor and that vertical panel, and fuel will seep thru eventually.

 

And here is a pic of that panel from the rear. Under the foam is a sort of cardboard layer then the steel. In most people's experience fuel smells will never completely go until you do the full job, tank out, foams changed, all boot flexible fuel lines renewed to latest spec, tank pressure tested and sealed if needed.
Greg

 

AND wash the boot out with detergent and a hose.

 

I would remove any fabric/etc part that smells like fuel. And then I would remove any fabric/etc part that was near the part removed.

I chased a fuel smell in my car for a bit. I could never precisely pinpoint the source. Even after sticking my nose against some foam sound deadener I didn't precisely locate the smell. BUT, after I removed the foam and put it in a plastic garbage bag and then smelled the inside of the bag (after it sit for an hour) that was the smell.

I was AMAZED at how the smell that I could not locate with my nose against the foam but it was unmistakeable once contained in a garbage bag.

 

Obviously a well worth while skill that you picked up along the line somewhere; garbage bag sniffer.
I shan't ask why.

 

The inability to find the fuel smell drove me insane. ;-)

 

Ok thanks all, especially for the picture of the reverse, that's a great help. I'll bin it & put some dynamat or underlay down in its place when I refit.

I think removing the tank just to make sure everything back there is ok will be my next step. I'm planning on replacing all the carpets anyway as they are original and pretty grubby & there are a few suppliers in the UK who produce full sets for a reasonable amount so that's not an issue, but I am worried that the fuel smell has permeated into all the leather; to have to replace all that will really suck.

 

The leather will be fine. Just give it a good feed with loads of (eg) Autoglym leather care stuff. Really slather it on and leave the car closed for a few days.
Leather Care Balm - Products - Autoglym
The modern stuff under the tank is a good idea, but nothing too thick,there is not a great deal of headroom, 1/4 inch is the max it will take or tank reinstallation is practically impossible. Also get the tank pressure tested, it could have a weep, even though very hard to detect.
Greg