engine hissing

[saxo_appeal]

Does anyone know why my engine sometimes sounds like its hissing?? its only when i start her up that she does this, doesnt happen all the time just after really hot days it does tho.
it goes away once iv driven the car for a bit

[R4T]

hmmm tricky 1,i had this problem also,was something to do with stepper motor and ecu coinciding so had to get it reset on a computer,could be a different fault,brake servo/air locked coolant system,if you take the radiator cap off is it bubbling like mad and wanting to piss out over the top?

[saxo_appeal]

dont know mate, i never thought to look there

[R4T]

depends how mechanically knowledged you are,you mite want try yourself i duno,have you stuck your head in the engine bay to listen is it a small leak but comin out quick or a loud 1 you cant tell where its coming form?

[saxo_appeal]

yeh its one of them, garage said not to worry but hey

[hesslevtr]

air leek from somewere