I went to fill up yesterday and before I thrust my nozzle into the hole.. I noticed a load of water just sitting there on top of the flapper that the nozzle needs to push past to get in to the tank.

It smelled slightly of petrol.. but was pretty much water.. but I can't for the life of me figure out how it got between the flapper and the petrol cap.

Anyway, I didn't fill up. I went home and used some kitchen towel to soak it up.

All is good, but it was a bit odd.

 

Most likely the water drain nipple is clogged. You should see it when you open the filler door....the little rubber nub next to the filler neck

Cheers
DD

 

I can see how that would explain water around the filler cap, but it doesn't make sense that it got between the cap and the inside filler flap. Also, there wasn;t any water outside of the cap at all.

 

Only a couple of things I can think of:
* Condensation ...though that seems a stretch, as you allude the quantity was more than a few droplets
* The fuel access door was unlocked and kids\hoodlums poured water in the tank.
.

 

Water will get into the filler neck aperture as it's not a water tight seal, hence the drain tube in one corner.

I had the same issue and the filter for the drain was clogged up with all sorts of crap

 

Same problem here, I cleaned the drain hole but still water does not go down...
I guess I need an air compressor to unclog it.
Any other ideas ?
BTW it was completely full of water and the cap completely sink inside the water.
I had to manually remove all the water with a towel. I dismounted the knob, cleaned it but the draining pipe is still clogged deep inside.

 

As you open the trunk liner panels under the left hinge you will see the line and it's routing through a hole in the trunk . If you don't get it right your trunk will be wet and rust . New hose at auto part store . Say hi to your Security ECU in that area .

 

If you find any stagnant water in the fuel filler bowl (#1) in the diagram below,



it means that the filter nipple (#2) is clogged and it is time for good clean up to avoid water build-up. It is clearly Jaguar's design fault. The fuel filler bowl is positioned level to the trunk lid, just next to the rear window glass hence making it a perfect collector of rain water, dust, debris, bird drops, leave fragments, and all sorts of dirt. However, the plastic filter nipple is just too small and easily clogged and even totally clear and free it cannot pass all water down the tube during heavy rain or a cash wash. So water will overflow in the fuel filler bowl, and find ways down the filler cap and then the fuel tank. Rose, my XJR, had a very bad experience of water in tank and fuel rail because she sat in the open for along time awaiting fix of a no-start problem. The only preventive measure is to keep the filter nipple as well as the tube (#6) leading to the trunk and beyond is similarly free from blockage, make sure that the filler cap (#4) is tightly closed and check that the spring clip (#3) is in place.

 

Weed wacker string trimmer line makes a great stiff, slippery piece of line to push down through the tube to clear it. I use it on sunroof drains too.

 

it seems like a great idea, I'll try it.
The filter nipple is clear so there is something stuck inside the tube.

 

update: I used a Weed wacker string trimmer wire and I cleaned up all the draining tube inside. Problem solved.

 

Hello Ric in RVA.

Your suggestion using string trimmer line is spot on. My XJ8 gas filler neck drain tube was clogged. After removing the debris that had collected inside the flap, I used your string trimmer suggestion to clear the tube. Multiple pokes in each hole, about 5 minutes later, drains like a champ.

Thanks again!

Bob G in Florida