RPM WS6

iTrader: (3)

I'm having an issue with one of my daily drivers. The last two times I filled up the tank, about 1 cup worth of gas will come spilling out right at the moment that the pump hits automatic shut-off. This has happened twice in a row now. The first time I just figured something was wrong with the pump. So when I went to fill up today I used a different pump (same gas station though) and had the exact same results.

I'm guessing it's got to be something going on with the car rather than every pump at the station, right? But what would cause this? I can't think of anything that could be wrong with the car itself that would cause this issue. Is it possible that this gas station might have changed to some new internal pumping equpitment that for some reason doesn't cut off in time when used on certain gas tank designs?

Any ideas?

I've heard of some people having issues with blockages, etc., in their tanks not allowing gas to go in even when the gage says empty, but that's not my problem. The tank will fill up all the way full just like it should, but the pump just isn't cutting off in time.

BeachZ

iTrader: (2)

Near the tip of the pump nozzle is a small hole, and a small pipe leads back from the hole into the handle. Suction is applied to this pipe using a venturi. When the tank is not full, air is being drawn through the hole by the vacuum, and the air flows easily. When gasoline in the tank rises high enough to block the hole, a mechanical linkage in the handle senses the change in suction and flips the nozzle off.

Maybe the hole is blocked? I know you tried two different pumps, but it's the only thing I can think of.

red beast

at the rate of fill up once it reaches the top and shuts off it's too late, I believe most will run out which is why I stand there while I fill up....

01WS6/tamu

iTrader: (37)

Depending on what type of vehicle it is it may have a restricted fuel tank vent or vent solenoid.

ghardester

Yeah, try setting it to fill up at a slower rate, not full speed. Other people pump my gas here in Oregon, I'm not allowed by law to do it mayself, so I keep an eye on them. If they are too busy to stand right there and watch it they usually set it on a lower fill rate so this doesn't happen. I doubt that anything is wrong with the car. But cars do weird things sometimes.

RPM WS6

iTrader: (3)

Thanks for all the replies guys. I just have some additional comments based on the replies here for everyone to consider....

BeachZ Thanks for the explaination on how the cut-off system works. I was really unaware of the details, but now I'm better educated on that.

To ghardester & red beast... you mentioned to fill the tank at a slower rate.... I have no issues with giving that a try. I will do that next time I fill it up. HOWEVER, keep in mind that I've owned this car for over 3 years now and I've always used the highest speed notch on the nozzle each and every time I've filled the tank. This condition has NEVER happened until these last two times that I filled the tank. If nothing is wrong with the car or the pump, then why is this suddenly a problem after all these years?

I also plan to try a different gas station and see if that makes any difference. Can anyone tell me if ALL the pumps at a given station use one central pumping mechanism for the whole station? If so, perhaps this station has recently updated the equpitment to something stronger that will now overflow a bit on the high setting before reaching cut-off. Just a thought?

The car in question is a '04 Cavalier.

ghardester

Let us know when you find out what's going on. I don't have any more input, but I am very curious as to the cause. I always pay attention to your posts 'cause you know your stuff and will find the answer.

Ferocity02

iTrader: (60)

I believe there is a seal where the inlet hose enters the tank. At least there is on most other cars. This seal may have deteriorated enough to leak. It happened on my friend's V6 Stang.

RPM WS6

iTrader: (3)

Thanks for the vote of confidence.

It will likely be a week before I can give a solid update. I want to run the tank down to the same level as the past two times just to keep things consistant. Not sure if the level would make any difference, but better to have as few variables as possibile. First I will try your suggestion of filling the tank slower. If that works, then I'll try a full speed fill at a different station next. If it doesn't work, I'll still try a different station next time.

If another station still does the same thing, then I'll really be lost on this one. Only other thing I could assume might be happening would be a tiny pin hole leak somewhere in the top of the tank; possibily disturbing the vacuum requirements of the auto shut-off mechanism.

I will post an update as soon as I fill the tank again.

EVILWS6

iTrader: (3)

I believe 00formula6sd(nighttrain1340?on this board) had the same issue with his Formula.I think he couldn't let it get below a 1/4 of a tank or it would have issues.I'll check the local board and PM him this link.

RPM WS6

iTrader: (3)

It seems that the gas is coming back out at the top of the fill tube though, since it gets all over the fuel door area, etc. But assuming my other tests fail, then I will investigate this next. Not sure how well I can inspect the fill tube to tank connection on this car without dropping the tank, but I'll check it out. Thanks.

RPM WS6

iTrader: (3)

Thanks, I appreicate that.

Funny you should mention that. These last two times that I've had this issue were both times where I ran the tank lower than I have in a long time. Both occurances were when the tank was just under 1/4 left.

Do you know if he ever fixed the issue?

EVILWS6

iTrader: (3)

Not quite sure,but I PM'ed him on the local and gave him the link to this thread.I don't know if he's still up though so it might be tomorrow.GLwith this problem.

RPM WS6

iTrader: (3)

Thanks again.

EVILWS6

iTrader: (3)

No problem.

nighttrain 1340

iTrader: (1)

You have mail

RPM WS6

iTrader: (3)

Replied to your PM....

Gun5

iTrader: (37)

mine did it once, made a fat mess after that nothing..

Michael02hawk

iTrader: (26)

I just have to ask...why are you not allowed to pump gasoline into your cars fuel tank?

twokss

iTrader: (5)

im in jersey. were not allowed either.