Fuel tank air locking?

[dthorb]

Has anyone else noticed a problem when filling up the tank . On my 59 plate bocanegra the tank fills up to the neck but when you put the cap back on you can hear the vapour escaping . Did this 4 times tonight when filling up and managed to squeeze another £15 of fuel into the car. Cut out at £50 to the neck and managed to get £65 in.
Any info appreciated .

 

[Beazy]

Has anyone else noticed a problem when filling up the tank . On my 59 plate bocanegra the tank fills up to the neck but when you put the cap back on you can hear the vapour escaping . Did this 4 times tonight when filling up and managed to squeeze another £15 of fuel into the car. Cut out at £50 to the neck and managed to get £65 in.
Any info appreciated .

On the right hand side of the filler entrance you should see a little green pipe type thing, moving that vents the tank.


When I go to fill up I always made sure to catch it and when I get to around 40ish litres I slow the pump flow down to about half speed and watch it take 52/3L

 

[Nath.]

On the right hand side of the filler entrance you should see a little green pipe type thing, moving that vents the tank.


When I go to fill up I always made sure to catch it and when I get to around 40ish litres I slow the pump flow down to about half speed and watch it take 52/3L

This is called venting, there is a little button that the cap presses when you screw it in and it vents the air.

The reason for the venting is to allow the fuel to expand with the heat in the hot summer.

If you were to fully vent the tank and leave it full in the hot sun you would have fuel bursting out of the vent and draining onto the road. Health and safety

 

[dthorb]

This is called venting, there is a little button that the cap presses when you screw it in and it vents the air.

The reason for the venting is to allow the fuel to expand with the heat in the hot summer.

If you were to fully vent the tank and leave it full in the hot sun you would have fuel bursting out of the vent and draining onto the road. Health and safety

Don't think I have ever owned a car that has £15 worth of fuel expansion, that is what the vents are for, fuel won't expand by a fifth of a tank.

 

[Nath.]

Don't think I have ever owned a car that has £15 worth of fuel expansion, that is what the vents are for, fuel won't expand by a fifth of a tank.

Expansion in the heat, health and safety, fuel slopping out onto the road via the vents when you go round a roundabout, fuel splashing out of the filler neck at you in a filling station. That's what it's all about

Don't forget that these cars are sold in way hotter places than the UK and there is always the fact that people do daft things like smoking whilst filling up. Don't forget the potential for static sparks from those shell suits in Liverpool too.

I fully vented my old MK3 Ibiza Cupra one summer, ready for a long run (400 miles each way) I did this at about 08:00 in the morning with plans to leave at lunch time. Parked it on the drive in the sunshine and started packing stuff into the car. By the time I was ready to go there was a puddle of petrol near the rear wheel where it had expanded.

 

[dthorb]

Expansion in the heat, health and safety, fuel slopping out onto the road via the vents when you go round a roundabout, fuel splashing out of the filler neck at you in a filling station. That's what it's all about

Don't forget that these cars are sold in way hotter places than the UK and there is always the fact that people do daft things like smoking whilst filling up. Don't forget the potential for static sparks from those shell suits in Liverpool too.

I fully vented my old MK3 Ibiza Cupra one summer, ready for a long run (400 miles each way) I did this at about 08:00 in the morning with plans to leave at lunch time. Parked it on the drive in the sunshine and started packing stuff into the car. By the time I was ready to go there was a puddle of petrol near the rear wheel where it had expanded.

You would have a slight expansion in fuel but not 10-15 litres worth, it would suggest a breather pipe may be causing the issue by creating a vaccum in the tank.
Pretty sure that seat would have to say the tank can hold 55 litres of fuel but you can only fill it to 40, seems unlikely.

 

[Seat-Ibiza-jake]

I filled up last night, (1.2 TSI FR) I managed £71 thats' shell V-power at £1.40 a litre. So is that 50 litres in my car? all I know is I had to vent the tank like mad.

 

[Stebb]

It's true, there is a 10 litre expansion tank in there, vented by the valve near the filler as suggested above. I can get 700 miles between fill-ups in my 1.6TDi by using the expansion tank too. Just push the valve with the filler nozzle for the last £15 worth of fuel. It's kind of hinged into the tank so be gentle!
Trouble is, it costs £75 to fill it (best Asda Diesel) from indicating 30 miles to go now.

Never had a puddle of fuel under the car, but then I usually fill and drive - the commute is 35 miles so will take 1/2 to 2/3 of a gallon out before I stop.

 

[DEAN0]

If i fully vent my FR 2.0TDI I can see 220 miles on the clock before the fuel gauge moves with a full tank range of 700 ish miles to the low fuel light.

Great for long trips but pointless otherwise.