Fuel tank overfow problem

[spaced1999]

Hi Guys
Hope you might be able to give me some clues as to what the problem is. Yesterday I was driving through town when a guy flagged me down at the traffic lights and told me I was losing petrol by the litre from the petrol cap. I pulled over and with the engine running petrol was being forced at a high rate out of the cap. I opened the cap and there was a very large pressure diff between the tank and atmosphere. I started the engine with the cap open and gases came bubbling through the tank and it overflowed.

Potentially pretty dangerous I think. The car was only in for a service 2 weeks ago and I am interested in what the problem might be and

a) whether it should have been picked up in a service or
b) whether it could have been caused by the service.

Thanks for your time.

Adrian

 

[Andy3004]

I'm not the best at these things but it sounds like the breather is blocked?

someone else will probably know better though....

 

[JamesL]

Was the car still running ok?

 

[spaced1999]

Sorry probably an essential piece of info. Yes the engine was still running ok.

 

[bivvyman]

Hi i have exactly the same problem on my leon cupra scared the jesus out of me thought the bloke who told me wanted a fight was waving his arms. lol if ya find the cause please let me know i will do the same back thanks Andy,,,

 

[bivvyman]

Hi can anyone tell me how to check the breather pipe and how to unblock it also where it is on the car
Thanks Andy,,,

 

[DPJ]

The petrol is pumped to the front of the car (to the fuel rail) and excess returns to the tank via another pipe. There is a third pipe that vents the tank to the charcoal filter at the front. No other vents.

It seems (rarely) the return pipe gets switched with the vent pipe. The connectors are at the front beside the round water expansion tank.

 

[bivvyman]

Mines in the garage as we speak for the same sh1t will let ya know the results an more scarily the price
Thanks Andy

 

[andycupra]

did you have any work done at the service?

a dealer took my pipes off around the charcol canister and didnt put them back on correctly. I had fuel spraying all over the engine..

 

[bivvyman]

well when i had it serviced few months back the mechanic said the fuel filter was round the wrong way ???? means not alot me but thinking it bout it after that when i filled up an unscrewed the cap it hissed like a coke bottle then it has progressed to leaking out. not sure if that is anything to do with it but have you got pressure in the tank when you unscrew the cap. have told my Hence new mechanic all this and he is sure he can sort it so just waiting now to hear the verdict

 

[andycupra]

right..
so the car was ok..
then had a service in which he has done work to the fuel filter..
then shortly after this you have had fuel issues..

so either the fuel filter was ok and is not now. or he didnt replace with new but turned the old one around..
or as above the pipes by the carbon canister have been unplugged and replaced incorreclty.

 

[bivvyman]

Seems somewhere around that mark. The good news is the new mechanic is a friend of a friend an a really nice bloke. he has never seen it before but sad not to worry he will hunt down the problem for me. So im just waiting to see his diagnosis. Stupid thing is the car drives like a dream an has lost no performance at all has yours

 

[adam cupra 20vt]

Mines in the garage as we speak for the same sh1t will let ya know the results an more scarily the price
Thanks Andy

Off topic...are you Andy the army bloke who makes the fishing stuff? Just wondered because of your name

 

[bivvyman]

No im andy a fisherman but not a army boy lol

 

[bivvyman]

Have had mine sorted it was the fuel tank in the end. Something in the filler neck had gone. Nightmare job to do but if its the same symptons as mine looks like you have the same problem. Hope this helps ya out
Thanks Andy,