Presure release when opening fuel cap

[Comuscomp]

I have just experienced something with my V50 2.0d MY2008, which hasn't happened before.

I went to fill up with diesel, when I undid the fuel cap there was a whoosh of pressurised air from the tank, the engine wasn't running, is this something to worry about?

I have had the car a few years now and have never had this happen before, could this be a sign of something starting to go wrong?

[Tony500]

Its normal to happen.... :)

[Welton]

Mine does it a lot, more after just a short run to the garage. Sometimes it's a huge draw of air. The tank runs a slight negative pressure so that the fuel 'fumes' can be recovered to a charcoal canister in the engine bay and neutralised.

[woody6046]

this used to happen when the air hole in the fuel cap was blocked , just put a straight pin or piece of wire into it to clear it and it should do the trick .