Strange knocking sound from fuel tank

[lazyitus]

Occassionally, I am getting a consistent knocking noise from behind the parcel shelf, assumably from the petrol tank.

What could this be ?

[Simple]

Do you get any suction when you take the filler cap off?

[lazyitus]

No

[Simple]

Okay, when you said about the knocking from the tank I thought it might be the breather problem where it gets blocked and you get suction in the tank causing it to knock as it is pulled inwards. Mine got so bad the tank imploded! But you would normally have noticeable suction on the filler cap when you take it off so that you can hear a hiss as it is released, if you aren't then not sure. Sorry can't be more help.

[lazyitus]

No, it's not doing any of that. But that's one thing ruled out, thanks anyway.

[K4TRV]

"Thumps" are venting issues with Charcoal Filter, TADTS, but not everyone hears them!

Noises (metallic) when going left and right can be a loose baffle.

Above can also be float catching side of tank or a baffle.

Any of those?

[lazyitus]

Thanks, TJS10 !