Stupid Fuel Cap Problem

[toxo]

I don't know if this is unique to my '2 or if it's a problem everyone has...

When I run my fuel tank close to empty, it seems to create a vacuum in the tank, so when I undo the cap there's a rush of air as the vacuum seal is broken.

If I run the car really low (like I did today when I got 360 miles out of the tank) the vacuum pressure is so high that I can't undo the cap, and have to get a set of grips on it. It was so tough today that even with the grips I could see the handle bit of the fuel cap flexing And of course this was in a petrol station and I'd had to borrow the grips....

I was under the impression the fuel tank had breathers to the carbon cannister, so does that mean my breather pipe is blocked?

Will the TRD fuel cap covers give me greater leverage to undo the cap? Any excuse

[Ryan S]

i have the same problem, i've had it on 3 mr2 now, i never tighten it enough so that it sticks anymore

[staffbull mr2]

i have this to on mine. it doesnt stick but when i unscrew a gas air noise come s out like how you described ,strange.

[nitric4k]

when I got 360 miles out of the tank

FIRST HOW!!!!!!


second all 3 of my mr2`s have done this too

[nikaiyo]

You can get fuel caps with like a little flap in the center to realese the pressure...

[toxo]

when I got 360 miles out of the tank

FIRST HOW!!!!!!

lol. The last 60 were done with the fuel gauge showing empty... and the 150 before that were done at 50mph on the motorway on the space saver!

second all 3 of my mr2`s have done this too

Fair do's then, sounds like it's normal. I think when I do away with the carbon cannister this will go away.

[Quigonjay]

always get the rush of air too

[Yas]

I drilled a very tiny hole through the cap, jobs a good'un

[Nick86]

just don't make it click when you tighten it after filling up.

[Steve Horrocks]

As above, mine does it as well, I've now got a small hole in petrol cap, never fully tighten it and keep a set of mole grips in the car!

[C50]

i remember asking a guy, "you look like a strong lad.."

I tried rubbing a thin film of silicone oil on the petrol car tread. The trick is to push in and turn. Works for me

[cosmos]

Is it air rushing in or air rushing out? My solution was to fit an early Ford Focus (or Landrover Defender lockable ) cap on a strap works a treat, it now dangles rather than being an individual nuisance.

[Razor04]

I've had this on all my mr2's and many embarassing episodes on garage forecourts i keep a set of mole grips in the boot just in case.

[C50]

well i worked out, if you push the cap in and turn the cap at the same time.. easy peasy!

[Si_Crewe]

I had a bad experience with something related to this on a Porsche ages ago.
Long boring story.

Anyway, I feared the worst when I had a similar problem on my MR2 but I've found that it can happen if you just spill a little fuel on the filler neck and then it dries after the cap is refitted and causes the cap to stick to the filler neck.

Since I've started taking more care when filling it up I haven't had the problem again.

Mind you, I wasn't getting the hissing noise when I remove the cap. For me it was just that the cap was physically stuck to the filler neck.

[craig]

yup mine has done this also. I just never tighten the cap so it clicks and it hasn't done it since.