SInce a few days something is builidng pressure in the fuel tank .
Never noticed before.

Any help is appreciated.

What is going wrong?

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Present cars:
My car: E-class 420CDI, 2008, W211, V8, 180 000km

Wife's one: C-class 220CDI Sport Coupé, Euro, 2002, W203. 345 000km

Son's one: GLK class 220CDI, 2009, W204

Sold E class 260E, W124, 1988 beloved car sold after 489 000 kilometres of reliable services (engine M103, clutch and 5 speed manual gear box all original).

E-class, W210 320CDI, 2000[/B], 225 000km, Sold

if you notice the whoosh when you open the fuel tank cap,then this is normal -used to get this on my 190e which i sold off and got a new jetta tdi.

perhaps you notice it more in hotter weather.