Shlurrrrrrrrrrrrrrrrrrrrrrrrrrrp

[lanciachris]

Thats what my cars saying to me when I open the fuel filler cap anyway.

I guess the vents blocked. any idea where it is? pita to access? im still new to this all so any hints appreciated.

Could this be causing any problems when driving?

[NurburgRob]

I\'ve never filled a car that didn\'t do this, even my mum\'s 06 Jazz

[hawker182]

My old 1989 vert did this too, never worried me though

[DC-TYPER]

mine does this, its as if it pressurised. i thought they done this to sports cars?

[lanciachris]

I mentioned it as i remember my jaguar doing it and reading about how it wasnt supposed to. I suppose it could be different on rexx\'s though

[LeedsLad]

mine does it too

[Rene7FD]

After the engine is cooled down, the coolant will have a little underpressure (English?).
Cooling down, the coolant is drawn back from the expansion tank through the small middle valve in the cap of the AST. The valve is (kept) closed by a spring, and the spring tension causes the coolant in the engine to end up in underpressure, just not enough to pull the valve open.
The underpressure is also the reason why you need to pull the cap off, instead of just lifting it off.