i vent mine to make the price a round figure lol!!!!! easier to work out how many pennies i have left in my bank b ut ne e had and problems but havent taken it to the extreme only put about 43lt in from empty
 
while waxing the motor today i had a look and i found what your all talking about never noticed it before will the air only release when the tank is being filled to the top?? il give it a go when i fill up next
 
all mk 4's have the vent leaver

it is activated when the cap is re fitted or you can activate it with the tip of the fuel nozzle and add some more fuel

I always do this to make the price a round figure...........( I hate shrapnel )
 
I've heard it when I put the cap back on. So I could always take the cap off and top up again. :)
 
The only problem I find with venting whilst filling, is that some diesel tends to splash out all over you!!!!![:@]
Aye, if you fill whilst pressing the vent, you have to do it slowly and watch carefully as the pump auto-cut-off won't work.

I used to vent-fill throughout my Ibiza ownership and also with the Passat, so have covered around 110,000 miles on vented fill-ups and never had a problem :)
 
Yeah you do have to watch the cap to ensure the diesel doesnt come flying out. You can normally hear it though as it gets to the top. Sounds like when you fill a bottle up if you know what I mean?
 
I just filled up, tried to do venting but ended up spilling derv down my car, only got 37.10 litres to tank, does that mean 8 litres left or air space?!
 
rash, if you fill to the brim and then vent the level will drop as the air comes out, then you can fill to the brim again, vent, and again, vent, and again

catch the idea now ?