2006 TDI Elegance estate.

 

Hey again helpful folks here, I’ve heard this in the past occasionally but recently (last week or so) seems to always make the noise when I switch the car off.

 

From the cabin it’s like hearing an electrical pump running in the engine bay, it stops after maybe 10 seconds after engine turned off/key out. 
 

I used to think it occasionally did this after using the AC but lately know it’s nothing  to do with that.

 

I think it’s this unit (pic) making the noise. So far I’ve no apparent issue, just the awareness of the noise that hasn’t normally been there. 

 

Anyone shed any light on what’s happening and if there’s anything to concern over? Thanks 

That is the vacuum distribution box there are only solenoid valves inside no motors 

16 hours ago, nige8021 said:

That is the vacuum distribution box there are only solenoid valves inside no motors 

Power going to it I see though?  While it's running on, from under the bonnet you hear it buzzing and from inside the car you hear more of a humming noise.

 

I'm wondering why it's running on after key off which it seems to do all the time just now. Can't say I have any apparent issue though because it stops after about ten seconds.

Edited 5 June, 20224 yr by silver50

This is the connections to the vacuum distribution box

 

 

N239 Variable intake manifold flap change over valve

N75 Charge pressure control solenoid valve

N18 EGR valve 

 

On engine shut down the N239 will be commanded to close, if that valve is clogged up with carbon deposits it might be taking longer to close and that's why you can hear the valve pulsating trying to close the valve