how do you vent a tank??and what is a swoosh gauge
- Thread starter jamesmacc
- Start date
re. Venting
Look inside the filler neck - there's a small switch like thing just inside the filler neck that the cap presses when you re-fit it.
This switch releases air from the top of the tank so that the fuel in the filler neck drops down to the tank. By keeping this switch pressed whilst filling, you can fit quite a bit more fuel in the car - bear in mind that you then lose any expansion capacity in the tank - so probably not a good idea to leave the car sat in the sun in the height of summer.
Look inside the filler neck - there's a small switch like thing just inside the filler neck that the cap presses when you re-fit it.
This switch releases air from the top of the tank so that the fuel in the filler neck drops down to the tank. By keeping this switch pressed whilst filling, you can fit quite a bit more fuel in the car - bear in mind that you then lose any expansion capacity in the tank - so probably not a good idea to leave the car sat in the sun in the height of summer.
personaly id not advise venting. its not going to allow loads extra anyway, you will hardly notice the difference and its there for a reason.
You may even lose some of the extra fuel.
You may even lose some of the extra fuel.
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Sorry mate but I cant help you there. I have a petrol so I dont know what sort of boost a diesel runs at, just that it runs higher boost than a petrol.
I vent mine If I get a 5p off per liter voucher, as said you can get quite a lot extra in with venting, I normally fill till it clicks then vent and fill at the same time and get another tenner in
Yes, I think that the correct way of looking at this is, if you have a TDI engine - well maybe, if on the other hand you have a petrol engine - then never excessively vent as it has been said that you can end up with liquid fuel entering the vapour recovery system and that can kill it - that comes from a VAG tech on another VAG forum. Personaly, I still tend to complete my fuel intake up to the next litre - then stop as it could get quite expensive to repair failed components.
I stopped venting because of the extra dollar it was costing at the pump. Getting on for £60 was hurting.
It does allow quite a bit more, typically 1 - 2 gallons, and if you cover a high mileage like me it does make a big difference as it means an extra day between fillups - can go a whole week if I vent
I've vented my tank at every fill for over 80k miles in the Ibiza and 70k miles in my Passat(s) it's never leaked once, I think petrol would be a different matter though.
You still use the same amount of fuel though, whether you put £10 in at a time, or £60, so it makes no difference at all other than psychologically!!
It does allow quite a bit more, typically 1 - 2 gallons, and if you cover a high mileage like me it does make a big difference as it means an extra day between fillups - can go a whole week if I vent
I've vented my tank at every fill for over 80k miles in the Ibiza and 70k miles in my Passat(s) it's never leaked once, I think petrol would be a different matter though.
You still use the same amount of fuel though, whether you put £10 in at a time, or £60, so it makes no difference at all other than psychologically!!
thing is, there is a difference between venting and filling up a bit more after the pump cuts off:
most pumps cut off a little early as the fuel tank get near full simply waiting after this cut off you can then put more in without doing any venting.
After this you can then get more in venting, but in my experience of a few cars (although they have been leons) is that venting would only allow another 2 litres or so. But if you start venting from as soon as the pump cuts out then perhaps you can get over a gallon more in. but thats mostly down to the pump cutting out early.
Some people say that when you put the fuel cap back on its permanently venting, and this is the case. But why have they designed it so the venting doesnt happen when filling up? this is so there is a volume of air in the system, and deliberately so. So when you fill up at night and then the car sits in the sun, any expansion will result in air escaping or compressing and not fuel. (which doesnt compress really.
Ok, ok, we dont exactly get extremes of temperature here so perhaps its not as critical as in some other countries so its probably ok in 99.9% of cases.
You are a lucky person as far as the petrol engined car is concerned - I used to to do this a lot as well, and got off with it it seems, but now that I have been advised as to what harm it can cause (and so money to fix), I've stopped doing it. It's very temping when you are about to leave the filling station and drive until the tank is "empty" - but with a petrol engined VAG car I'd still give it a miss.
A lot of diesel VAG folk just remove the "nipple" as it will not cause them problems.
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