Hissing Peugeot 307 1.6 (MY2003)

[TomTom0507]

Hello,

I have been using my dad's car recently (a 2003 Peugeot 307SW 1.6 petrol), and when I start it up, there is a loud short hiss. Im not too sure where it is coming from, but it only happens when I start it up after a few hours of non-use. The ignition also takes a few seconds to fire up the engine.
Anyone else experienced similar issues or ideas on what it could be? No leaks found.
Thanks in advance

Tom

[imagineifyeswill]

If the noise seems to come from the rear its possibly the in tank fuel pump priming the system,its normal to hear it when you turn on the ignition but if its it abnormally loud it would appear the pump is struggling, pump on way out or blockage on filter in tank.

[TomTom0507]

Thanks very much for the reply. This is very helpful! I will look more into those areas. :-)
Many thanks