Hissing Noise from the engine after is is turned off?

[Rossco_111]

I have recently purchased a 2007 GTI and I luv it!

I noticed today when I was checking under the bonnet a hissing noise after the engine has been turned off. After a period of time it stops. Is this 'normal' or should I be looking for a split hose or something?

[6RGTi]

My understanding is its something to do with the intercooler pumping oil or something through the motor to help cool it. My Polo GTi does the same thing

[Rossco_111]

thanks 6RGTi

[vdubmotorworx]

manifold pressure valve leakimg mate by the sounds of it.. noise lasts about 6 seconds after turn off and is coming from right hand side of engine cover?. try taking the oil filler cap off when the engine is running..usually when the valve is gone you cant get it off. turn engine off wait for leak to finish and will come off easy? try it and let us know... VDUB...