x98boardwell

I have a slight fuel smell from the rear of the car. This has been here since I purchased it.

When trying to diagnose the problem I took the access cover off to the fuel pumps and everything is bone dry and no smell.

After speaking with someone on this forum they said there is a gasket on top of the tank through the access panel in the trunk area. When I took that cover off it also looked dry but I do smell fuel slightly (and I the car has sat for about two months so of course it would be dry). Is there another boot below the screw cap that I can remove? Is the gasket that can go bad under this cap that i just need to remove and replace to ensure a good seal?

Anyone else ever have this smell happen and it be something other than the two things I just checked?

Thanks,
Bryan

Nicole

First thing I would do is remove the cover at the rear bottom of the tank, and check for a leak at the fuel pump of fuel filter. This is the most likely area of the leak, assuming it is on the outside and rear.

The more common source for fuel smell inside the cabin is a broken Y-Connector of the fuel evaporation system, which is located in the right front fender, hidden behind the fender liner.

PS: How do you convert a 928S4 to a GT? Did you swap the transmission to a 5-Speed?

x98boardwell

As stated in the OP I did remove the bottom cover and it was bone dry and no smell. Also, the smell is from the rear of the vehicle and not in the car so I am looking for other solutions like the pictures I posted as a possible culprit.

MainePorsche

Have you viewed these rearward areas for visual or olfactory presence of gas while running ?
My rear end smell was from a driplet leak while running at the fuel pump.

Kevin in Atlanta

Had the same thing happen to me. Smell was coming from the fuel pump/filter area - coincided with a much louder then normal fuel pump on a drive on a full tank from SC to GA. I did a search and there was mention of fumes leaking past the fuel filler gasket. Has not happened again - but I subscribed to this thread to see what it turns out to be.

Nicole

Sorry for missing the reference to the fuel pump cover.

I recall that there were cracked tanks and leaks in the filler neck area in the past. But I have never experienced any of those.

Mrmerlin

be advised there is a vent at the rear center of the chassis just infront of the rear bumper this can let fuel fumes out, look up while lying on the ground under the rear bumper cover

Otherwise your tank cold be getting perforated from age the simple thing to do is Before you fill it .
Drop the tank and inspect it.
Be aware of the transfer line that goes through the chassis.
Look for tell tales of prior wet areas.



Also look carefully at the bottom of the tank saddle where the fuel hoses run through, it might be a good idea to drop the saddle and clean out the mud .

NOTE support the tank with a block of wood while the saddle is out. if your not going to drop the tank.
NOTE also refresh the saddle foam ACE has the foam you need.
NOTE dont let the tank drop as you could crack the transfer hose connection at the T fitting.

Dropping the tank might be a good idea

Turc928S4

Something similar happened to me. The gasket on the top of the tank was leaking. When I was filling up the tank, a pool of gas was forming on top of the tank around the fuel level sender. I replaced the gasket and it solved the gas smell problem.

x98boardwell

Thanks everyone, I will check everything again while running and also add some gas while the cover in the rear is off to see if there is any leak.

If nothing there looks a miss I will look at the vent area and proceed with the possibility of dropping the tank as a last resort. All other things look to be in good condition.

I will update once I found the problem and solved it.

Turc928S4

make sure the tank is full if you want to test for the leak

x98boardwell

To clarify was the pool of gas around the filler area happening while filling or once it was full and driving?

I was thinking you meant while filling so that is what I was going to do. Could you clarify when it was actually leaking so I know for sure? Want to make sure I simulate the same situation. Thanks for the input.

bronto

Check your rear deck above the tank to see if any holes were drilled. A P.O. of mine mounted stereo equipment there, and the screw holes he drilled went straight into the tank.

Turc928S4

after I filled up the car, gas was leaking form the fuel level sender gasket directly on top of the tank. I don't know how fast it happens, but when I got home, I checked the tank through the access hole and could see gas around the level sender. If you look closely, you will notice that the level sender unit is lower than the top of the tank. that's why I said that you have to have the tank full to see the leak.

x98boardwell

No holes bronto.

Thanks for clarifying Turc928S4

x98boardwell

Found the smell, now just need to see how to fix. I am guessing this one line but would like a picture and directions on best way to remove this lowest panel under tank so I can see where the line terminates on the bottom. Where does the line go up top? It seems as though there are two that travel up that way but only one comes to the top of the tank...

The line (at least the padding on the outside) seems to be disintegrating and that is where the smell is coming from. When I removed the cover this is what fell out... years of dirt and road grime and it smelled like fuel and seemed wet.

Any ideas and pics of what this looks like under the bottom cover and how to remove it? Also, what part number for line and potential schematic on how these lines are channeled and used for.

Thanks,
Bryan