Purge pipe?

[skullmunki]

Hi all,

Just a quick question....

Can someone explain the purpose of the small rubber hose that connects to the airbox, just under the maf inlet? I've heard it referred to as a purge pipe, but what exactly is its function?

thanks!!

 

[Andrewcupra TDI]

dont know but when mine was disconnected it didnt like starting tidy , was all lumpy and stuff

re fitted now seems better

 

[mr_D]

no good without pics. where does it go to?

 

[MJ]

The pipe in question is the main air feed to both the EGR and boost pressure solenoids, it might also be where it dumps any excess air - "purges" it back into the air box once the engine is turned off or it is no longer needed.
It is part of the vacuum system for the control of the turbo and egr functions, although the system takes its vacuum directly from the servo hose directly off the vac pump it must also need an air supply or somewhere to dump air at some point also.

 

[skullmunki]

no pics of mine as i'm at work at the minute but best I can do is image #3 from this fitting guide.

 

[MJ]

no pics of mine as i'm at work at the minute but best I can do is image #3 from this fitting guide.

Yes mate it does what i've posted above

 

[skullmunki]

The pipe in question is the main air feed to both the EGR and boost pressure solenoids, it might also be where it dumps any excess air - "purges" it back into the air box once the engine is turned off or it is no longer needed.
It is part of the vacuum system for the control of the turbo and egr functions, although the system takes its vacuum directly from the servo hose directly off the vac pump it must also need an air supply or somewhere to dump air at some point also.

Thanks for the info mate....question is, will it still work properly if its disconnected from the airbox? (i see Andrew had problems)

I'm after fitting a cone filter and am just wondering what to do with this pipe.

 

[MJ]

if you buy a k&n cone filter (as in your pic) it comes with the correct fittings and holes for it. i have a k&n on mine and it works well, nice grunt, better pick up etc

 

[skullmunki]

It's a nice big jetex filter, but unfortunately there's nowhere to attach the hose to.

I've got a straight piece of silicone to go on between the maf and filter, i'll tap it into that me thinks

thanks for your help