Went to fill up today and when I opened the filler flap the entire plastic of the cap and the interior of the filler 'box' was covered in delicious petrol. When I turned the cap, it seemed a bit looser than it usually is (I assume that was at least partly to do with the lubricant properties of the fuel) but still made the same noise as it always does - the sort of 'breathing out' thing as the pressure is equalised.

 

I've narrowed it down to four possible things:

 

1. The filler cap or seal is knackered.

2. I didn't put the filler cap on properly.

3. I DID put the filler cap on as I usually would but haven't used enough force, and as a result the cold weather has loosened it up sufficiently to cause the fuel to leak out.

4. Someone has attempted to siphon off some petrol. I realise that's probably the least likely scenario.

 

Question: has anyone else had a similar problem? Do you have to tighten the filler cap more than I usually do? I usually give it one click on the ratchet and try not to be too heavy handed with it. There is no visible damage or wear to the filler cap or opening, but it's definitely leaking.

Unless you used almost a full tank in a day or there was a lot of fuel leaking wouldn't it have just evapourated from around the filler cap?

The tank is a long way from the filler and I'd imagine unless you've given it a hell of a thrashing it would be difficult for fuel to splash all the way up the filler pipe?

 

It was definately petrol around the cap & not rain water mixed with the last drops/splashes of petrol from last time you fuelled up?

 

I can't recall anyone else mentioning issues like this on the forum previously.

It was definitely undiluted petrol - I got it all over my hands from the filler cap. And yeah, it's very strange because I hadn't been throwing the car around corners, nor had I sprayed petrol all over the place when refilling previously.

 

The thing that confuses me is that it was all over the actual filler cap itself - as in the outside part of the cap that you grip to turn it, not just the threaded bit that slots into the filler hole. Thinking about it, that's the last place you expect it as if it's been leaking from under the cap, it would have to essentially drip down from underneath and then 'jump' back up onto the outside of the cap. It's a decent amount of fuel, enough to completely cover all of the plastic parts behind the flap (but not leaking out of there onto the bodywork, as far as I can tell).

 

Is there any way in which fuel could become 'caught' in the filler pipe so that it's closer to the filler and able to spill out? I'm thinking a faulty anti-siphon mechanism or something along those lines. Or could it be evaporating in the pipe and then condensing when it hits the cold air/parts towards the outside of the car? I'd think it's unlikely but I'm pretty much stumped for an explanation here.

There no sign that someone tried to force open the filler door?

 

I guess you've already cleaned/dried the parts & refitted?

 

I would take a look after a few days & see if it comes back.

If there's no signs of more fuel it may be one for the "unexplained" case files.

Can't see any signs of tampering at all. The car is only ever on the drive or in my parking space at work, so it's not left on the street - and my understanding is that people don't tend to bother trying on modern cars because it's so difficult. This is why I pretty much discounted fuel theft as an option, but now I'm starting to wonder!

 

I've cleaned it off this morning - was too dark to see what I was doing last night - and will keep an eye on it for the next few days. If it happens again, I'll take it in for someone to have a look over (I've got about two months' warranty period left so if it does happen again, fingers crossed it's before mid-February!)