Clio 1.2 hissing coilpack

Car recently started hissing sounds like its the coilpack but i changed that and the plugs around 4 months ago so i don't think its that. I cleaned the throttle body today its not that and i cant see any broken hoses or anything but it doesnt sound like its coming from near any hoses. Should i change the plugs and coilpack again or does anyone know any thing else it could be?? The cart runs fine the only thing I have noticed is when i changed to 2nd and put my foot down it has like 2 little jerks before it goes properly. And also it has a low idle of 500rpm but it has always been like that since i bought it. The idle seems fine though its not lumpy or cutting out.
 
spray round with some wd40 or brake cleaner and see if the engine note changes as you could have an air leak
 
I done that this morning I sprayed around the inlet manifold, throttle body and the air pipes but I got nothing think I might just leave it till it gets worse then I can plug the machine in