Fuel Tank / Filler / Cap Issue

[Rusty_McRusty]

Hi all, following a day on a counter-clockwise circuit, a rarity in the UK, I experienced an issue with fuel leaking out of the filler cap and then down the side and rear of the car! The first I knew of it was a strong smell of petrol with the window down (I think it drew the fumes from the boot) and at that point I immediately came in! On the road, before and after, the car was 100% fine.

It was a wet day and as such I was getting the odd drift on, sometimes with a few stabs at it due to a mix of surfaces in the same corner changing the grip levels substantially. However, I think this was a small contribution to the general cornering forces, although the fuel would have got its slosh on.

So, after some advice to stop the issue. I need to check the integrity of the filler at some point but the obvious path that the fuel was taking was clear for all to see as the dirt and detritus had adhered to it, making it look like some hotrod flames down the rear 1/4.

I was thinking a new filler cap to ensure that the seal and locking mechanism were as intended but also thought about the addition of some fuel tank foad to the top of the filler to be used for such days and take the energy out of the fuel as it comes up the pipe. This would also allow any breather duties to be retained.

Car is a road car so a fuel cell isn't practical and also, as most track days are CW, this issue really isn't going to happen often, still, forewarned is forearmed.

Cheers for any advice.

[UweM3]

Don't know if all E30's are the same but the M3 has an overflow plastic tank in the wheel well under a plastic cover. There are a lot of pipes. Check if they are still in good nick.
Are you 100% sure it came from the filler cap?
I have had isses as well, but it turned out me not turning the filler cap properly to the close position after filling up because the cap was a bit beaten up and didn't turn easy

[Rusty_McRusty]

I have no photos but all the fuel eminated from the filler flap and then spread out down the car.

Thanks for the hint on the extra gubbins back there, I'll need to get the inner arch out and have a look and see what's what.

I think the filler cap option is the place to start, for all I know it's 20 years old and has been dropped 101 times before I bought the car. It's not stiff but isn't smooth and silky either.

[si-]

ive had this problem although it was on a drift day so any solution you come up with post it up