General Petrol cap vacuum

[imthejoker]

Hello all , when i juice up i remove my petrol cap and theres one heck of a vacuum sucking air into the tank ,is this the norm or has my marea got its own Fiat unique-ness??
Many thanks for all replies

Joker

 

[FDF]

I think it's normal, happens with mine too Also happens on other cars I drive.

 

[imthejoker]

Thanks for the reply mate , sorta sets my mind at ease.

Joker

 

[AnfielRed118]

Happens to mine as well.

 

[Adrian Bravo]

Its normal on my Bravo and in the Manual it says its normal aswell.

 

[Renegade_8]

With FI it's normal and shows the tank return lines etc are in order. It tells you this in the Marea handbook as well.

 

[imthejoker]

Thanks for all the replies guys , im wondering if as an experiment - im gonna drill a very small hole through the petrol cap so's to stop the vacuum n see if it makes ant difference to the running / mpg - any feedback on this please?

Joker

 

[werdna]

Why try to fix what 'aint broke ?

 

[imthejoker]

fair play dude,its just my luck is the vacuum will suck in a passing stealth bomber thats got no licence or insurance.just wat i need.

Joker

 

[Adrian Bravo]

Thanks for all the replies guys , im wondering if as an experiment - im gonna drill a very small hole through the petrol cap so's to stop the vacuum n see if it makes ant difference to the running / mpg - any feedback on this please?

Joker

Id thought about driving with the cap off as a test, but came to the conclusion fuel would go bad because fresh air would get to it.

Wonder if the pressure puts strain on the fuel pump? I dont know. I dont have knowladge of fluid dynamics

Ive noticed my car is quicker after a refill, that could be down to the vacume being released or maybe the fuel is a bit fresher.

 

[imthejoker]

Wonder if the pressure puts strain on the fuel pump? I dont know. I dont have knowladge of fluid dynamics

Ive noticed my car is quicker after a refill, that could be down to the vacume being released or maybe the fuel is a bit fresher.

Bloody good question mate - can anyone give us a viable answer to this pls

Joker

 

[bulldog5046]

i'm fairly sure the vaccume is to prevent an explosion from the fuel vapours?

i wouldnt advise running without the cap or drilling a hole in it.

 

[Most Easterly Pandas]

Thanks for all the replies guys , im wondering if as an experiment - im gonna drill a very small hole through the petrol cap so's to stop the vacuum n see if it makes ant difference to the running / mpg - any feedback on this please?

Joker

The vaccum is there to ennable the evaporative system to function properly.

No vaccum will mean the system won't function properly, enabling fuel evaporation which is harmful to the o-zone (apparently ) and meaning you loose fuel.

Also petrol only has a 3 month 'best before' date in open air, where as that doubles to 6 months when in enclose containers (e.g. a pressurised tank)

i'm fairly sure the vaccume is to prevent an explosion from the fuel vapours?

i wouldnt advise running without the cap or drilling a hole in it.

Also the point above.

Just for note, the vaccum shouldn't muck up or have adverse affects on fuel pumps running into several PSI and that majority do on modern cars

Jon.

 

[imthejoker]

Thanks all so very much with your helpfull replies-its clear that my vacuum whilst sucking in passing flocks of geese is nessessary in the efficient running of my marea , again - my thanks to all

Joker