paulgtt Posted December 29, 2012 Report Share Posted December 29, 2012 I will start from the beginning incase anyone picks something up on the way. Bear with me! Ok so I filled the car up with petrol on 21st December, filled completey plus a few pence extra to make it a round figure (yes im weird like that!) drove the car after for around 10 miles, faff style! Got home and parked on the drive as normal. Went out to get something from the car yesterday (28th) at 4pm and everything is fine. Walked upto the inlaws last night at about 7:30pm and still everything fine, get home around 11:30pm and as we go to open the front door of the house a very strong smell of petrol. Grab a torch and fuel is coming out of the car and its dripping down the rear of the wheel arch,first though is someone has tried to syphon it out but no damage or marks anywhere on the car, can't see any sign of hole in fuel tank or anything. So I pop the fuel filler flap, also noted that the gauge on the dash hasn't moved since last time I drove it, unscrew the fuel cap and then it starts running out of the overflow! I let it run and it stops after a few seconds but the fuel is mm from overflowing again. Grab a bucket of water and wash the drive and the side of the car down. I then think is it because the car is on a bit of a slope, so get in start it and it starts fine, come off the drive and reverse back on a bit straighter, turn engine off and left it a few minutes. Unscrew the cap again and the fuel is mm from pi**ing out again! So lock it all up and went to bed. Go out to it this morning and theres fuel dripped down the rear of the arch again, although none is on the floor this time. Unscrew the cap and it pi**es out again!! The only time the car has moved between the 21st and the 28th was when I had to move it a couple of feet foward, just let the handbrake off, to get the wheelie bin out on Boxing day. It seems very strange how its happened in a 7 1/2 hour window aswell, was fine at 4pm but coming out at 11:30pm. Its as though more fuel has been added! Whats going on!!!??!! Any help or ideas welcomed! Link to comment Share on other sites More sharing options...
mooey65 Posted December 29, 2012 Report Share Posted December 29, 2012 Pull out the arch and check the breather pipe I had to cut some of mine away and pop a 12.5mm pipe in place Link to comment Share on other sites More sharing options...
Dorris Posted December 29, 2012 Report Share Posted December 29, 2012 (edited) Fuel will expand and contract with temperature, the more fuel youll have the more it will expand and if its full to the brim then it has to go somewhere its the nature of the beast. Take the car for a thrash for a few miles and it should settle down. I use to see it a lot with jet fuel in tankers which was less prone to expansion then perolium. Dorris Edited December 29, 2012 by Dorris Link to comment Share on other sites More sharing options...
paulgtt Posted December 29, 2012 Author Report Share Posted December 29, 2012 Thanks, I did think about going for a drive to see if it would go down and stay down! Thing is though is that I usually brim the tank when I fill up and it hasn't happened before, although it has been fairly cold recently and has got quite mild the last few days. Thanks aswell Mooey, I will check the pipe also. Link to comment Share on other sites More sharing options...
chan110 Posted December 29, 2012 Report Share Posted December 29, 2012 Never had a problem (yes i round my up too whn filling up). Even in the middle of winter/summer whn i filled to the brim with petrol, but only use LPG all day, thn park car on the slope drive - no probs. Hope u find the cause. Link to comment Share on other sites More sharing options...
celica-190 Posted December 29, 2012 Report Share Posted December 29, 2012 Sounds like a blocked breather pipe for expelling the fumes Link to comment Share on other sites More sharing options...
Black Knight Posted December 29, 2012 Report Share Posted December 29, 2012 Now I’m not entirely sure here but…the fact that it is coming out of the filler when the cap is removed must indicate some sort of pressure build up in the tank. And the reason for that must surely be a blocked breather pipe as the whole point of it is to let fumes and pressure out of the tank. Cant be that the breather pipe is corroded to the point of holing as that would still allow pressure out, but must be blocked in some way. Very strange none the less and I would think the only way to investigate safely is going to be to first burn off as much of that tank of fuel as possible so that you can safely remove all the pipes to find the blockage. When my breather pipe corroded through it leaked only when brimmed full, but the leak was under the car directly onto the rear suspension arms, passenger side. Like Mooey garage fixed mine by cutting out the corroded section and fitting a longer rubber pipe section. Link to comment Share on other sites More sharing options...
trophytr5 Posted December 29, 2012 Report Share Posted December 29, 2012 I had the opposite problem with an old MGB. I left the filler cap on a petrol pump and drove off without it. To replace it I "borrowed" one from a BL Mini. Drove from Manchester to London and had just turned onto the A5 (this was before the M6 went all the way) and ground to a halt. Fuel gauge showed half full. Called out the AA and the first thing he asked was had I any fuel? Yes, I says, the gauge shows half full. Have you checked the tank? No. So he goes to the back, takes off the fuel cap and there's the sound of air rushing into the tank. The MGB filler cap had a breather, the Mini didn't. Airlock in the tank. So it could be expansion (remember that fuel is stored underground where it's probably colder and a blocked breather pipe. Try driving a long distance and see if it runs out of fuel before the tank is empty. Link to comment Share on other sites More sharing options...
Monkey_matt Posted December 29, 2012 Report Share Posted December 29, 2012 had a similar problem with mine, but never any petrol leaking that I could see, just a strong smell of it, but to me, it only happened in summer, and after I had just filled up, I just put it down to fumes leaking from round the cap, from the fuel tank getting hot in the sun Link to comment Share on other sites More sharing options...
Stu-82 Posted December 29, 2012 Report Share Posted December 29, 2012 I had a similar thing happen when i brimmed my tank at the petrol station one time. I stopped filling and just as I removed the nozzle petrol started overflowing as if there was still more going in, i quickly put the cap on to stop it pouring out then curiously i removed the cap to see what happened and as i pulled it off the petrol rised up and started coming out again so i put it back on and took a longer drive home to bring the tank level down. i haven't over filled it since and not had the problem again. One thing i have noticed when i remove the filler cap when the tank is low i get a hissing air sound, not sure if the pressure is going in or out of the tank but should this be happening unless the breather pipe is blocked?? Link to comment Share on other sites More sharing options...
Black Knight Posted December 29, 2012 Report Share Posted December 29, 2012 (edited) One thing i have noticed when i remove the filler cap when the tank is low i get a hissing air sound, not sure if the pressure is going in or out of the tank but should this be happening unless the breather pipe is blocked?? As far as I am aware a hissing or fizzing sound when removing the fuel cap is a good thing. Means the tank has no leaks and the system is running at a good pressure Both our 6's give a nice fizz when stopping for fuel :xmas_biggrin: Edited December 29, 2012 by Black Knight Link to comment Share on other sites More sharing options...
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