Quote Originally Posted by leemasiuk View Post
thanks for the reply.

sorry the question doesnt explain well enough.

I really dont think this is a normal sound, as it has only started in the last week. The hissing is quite load when i accelerate hard. like compressed air being released. you can easily hear it with the windows closed. Sometimes it seems louder.

i wonder if a loose/split hose/pipe could casue this. but i dont really know where to start looking? Any suggestions?

the performance seems a little down too (not a much boost on acelerating) and also the mpg seems to be worse than normal.

If this is normal, i dont understand why it has not made this noise before?

hope this helps to explain a little better
Check the boost pipes for leaks...tighten everything that looks or seems loose.You have faults stored in the memmory that will need erasing. All should get back to normal after that. Hope this helps.