Recently found that both (!) fuel tanks have small leaks. Pulled the L body panel and cleaned off the muck–couldn’t see any leak. Topped up (1.5 gallons) left tank and drove 10 miles. Can now see that gas is running down from above, at rear of tank on interior side of tank. It’s above the ‘bulge’-- that’s several inches above the bottom of the tank–so I can’t see exactly where it is coming from. I don’t know where the return line runs into the tank but it’s not up on the side is it?
Areas around the sender and drain are dry.
Seems weird that I would notice both sides leaking at more or less the same time. I don’t think I have a changeover/valve problem but will try to check that today.
Your fuel tanks are 32 years old and made of steel. The chances that they’re rusting out from the inside are unfortunately very good. Best to pull one out (not that difficult) and have it acid washed inside and out to see what’s really doing on. My guess is that you’ll find a myriad of very small pinhole leaks so small that the fuel doesn’t leak but rather oozes out.
I dealt with a very similar problem with my series 1 XJ6 when it was the same age.
It may be that the tank is not “venting” well and oozing out of the filler neck and running down the tank. I just installed a brand new one and that is what happened to me. Does your tank always leak no matter how full it is? If so, that ain’t the problem. As Rozanna Rozanna Danna would say, “Never mind”.
Phillip
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There is also a return line from the fuel separators quite far down on the tanks, Thon…
It may be a spigot leak - but Grooveman’s point cannot be excluded, of course. Remove the tank units behind the rear lamp clusters for a better look inside the (emptied) tanks? It may at least give you an idea of the general state of the tanks’ inside?
Any chance I can have a look at that area without pulling the tank out? I don’t want to shop for a new tank just yet, but I have been loosing fuel since England, overnight. Don’t look too bad inside from what I see, if anything it’s a pinhole.
The tanks need to be quite low to pull the sending unit (maybe ¼) but it does give you a good starting point.
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Have look inside the tanks, Thon - may give a clue…?
There may be extensive visible corrosion confirming a refurbishment is required. Unfortunately; if it is a spigot leaking; the only way to access is by removing the tank(s)
Main point is to get as much information as possible - before action is taken…
