2000 1.6 Inlet Manifold Pressure Build Up?

[Focusfan88]

Hi everyone, I was wondering if anybody can help me! I have a 2000/x reg focus 1.6 petrol zetec estate, just changed the fuel filter and oil filter yesterday, and since doing that whenever I switch the engine off I get a whooshing sound (similar to a dump valve sound) seems to be pressure being released through the air intake, also I've recently fitted a cone filter, so maybe it's always done it but I just couldn't hear it through the standard baffled air box? Just wondering if this is normal or if I have a problem?!

Any info would be much appreciated :)

[Focusfan88]

OK, today it only seems to be doing it if I switch the ignition back on after switching the engine off, the car is still running fine, just makes this sound after its switched off! Maybe my description of the sound wasnt great either, so here is a vid of it:

or if embedding it doesn't work, here's a link:

again any help or info would be appreciated.

cheers

Dan

[mick85]

Check vacuum rubber hoses common issue on focus

[Focusfan88]

Ok will do, thanks.