petrol cap

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petrol cap


New member
Mar 1, 2006
Can anyone please tell me the main purpose of a lockable petrol cap?

A week after I got the cinq I was stuck with motorists queuing behind me at a garage while I struggled to get the petrol cap off (same key as the ignition and was afraid to break it!)
I pulled up near car wash and it took me an hour (men came and went and tried their best to help-BLESS!)
I eventually got it unlocked and off by putting the key in only half way!

I have been unable to get it back on the car now.

So now I have had to buy a universal green cap from a garage.
I read that it said something on the back like 'this is only for temporary use and should be replaced....'

I would like to know the main reason....besides the fact it cannot lock! that the only reason!
I imagine mis-use of others may be a reason (eg...deliberately setting it alight or syphoning the petrol!)
A lockable and properly sealed fuel cap is an MOT pre-requisite (sp??)

It also stops fuel coming back out.

Just squirt in some WD40 into the lock with the key half in and work in the oil, should be great after that.

When I couldnt get the cap back on I went past Halfords (or is it Halfrauds) and called in.
Told this guy in there my problem and he told me they sell unlockable ones for 4.99 and lockable ones for 14.99.
He then took me to one side and said if you soak it in WD40 over night and spray some on key too then it should work.
Went home and did that.
No joy.
Therefore 1 good point for sales assistant in Halford is that he didnt rip me off!!
Bad point is that the same 'universal' petrol cap he told me was on sale for 4.99 in Halfords, was only 2.99 at a local petrol station!!!!

I will keep trying the old petrol cap.

Sharon I have said on previous threads I have a problem with a petrol smell in cabin....lack of a locking petrol cap has surely nothing to do with it!!
Although your car is fitted with an anti-syphon device, preventing people from stealing your petrol; if you don't have a locking fuel cap, you leave yourself vunerable to people pouring various liquids into your petrol tank.

That would cost you a lot more to put right than the price of a locking fuel cap.
fixitagaintomorrow said:
You need a proper cap, as the tank runs slightly pressurised.

There you are Sharon the answer has come from our own F/F celebrity :D
T.O.T.P had one and his name was Jim :) but ours is Pete will fix it :p :D (y)
Since this petrol cap prob happened it seemed to coincide with the petrol smell I am getting.
But the smell seems to be coming (probably-I am no expert!) from the air vents but I dont sniff em while driving-its just a guess.
There is no smell of petrol in boot,engine or near petrol cap etc.
I want to look into it this weekend as I may be able to afford any work that needs doing next week!
I walked into a shop last week after getting out of the car and someone said "can you smell parraffin?"
I think it was me!!
Not good!
Any ideas?