Gas nozzle will only run 20 seconds

Gas filler nozzle stops after 20 seconds

It seems on some cars the baffle system is too close to the end of the filler nozzle. Carefully backing out the nozzle about an inch or so will allow it fill normally. Too much pressure is built up and trips the sensor if it is to close.

Hmmm…Would this by any chance be a Hyundai Elantra? This sure sounds like a question from today’s radio program.

Anyway, the best case scenario is–as Tom and Ray stated–a defective valve in the car’s evaporative emissions system. That is a relatively cheap fix.

The worst case scenario–which was apparently the one envisioned by the caller’s mechanic–is that the evaporative emissions system’s carbon canister needs to be replaced. That is a $300.+ repair job, unfortunately.

If it turns out to be the carbon canister, you can avoid replacing it again by stopping the gas pump as soon as it first clicks off. Drivers who insist on continuing to force gas into the tank after the pump first clicks off are the ones who wind up with the situation that you have, and they are the ones with the hefty repair bills.

Why are there so many posts about this problem? and from so many different type cars? Is everybody trying to top the tank off? what do all these posts have in common except a symptom?

[i]  Is everybody trying to top the tank off? [/i] 

I believe you have it right. Back in the old days, everyone topped off their tank. The service station always did it (it increased each sale a little) so when self-serve came out drives did the same thing. Not long after came pollution controls on the vent system and charcoal chanters which could be damaged by topping off the tank.

[b] OP if you have been topping off the tank, you may have created the problem.  Don't top off the tank.  You might try that for a while and see if in time it will let you fill the tank further without clicking off.  If not you may need to replace the canister.  It is also possible you have a blocked (crimped) hose or maybe you need to try a different station some stations seem to have nozzles that just don't get along with some cars.  [/b] 

Good Luck

The driver said that the nozzle clicks off after 20 cents worth. That is less than a cup of gasoline at the present price. I am wondering if there is a restriction at the lower end of the filler pipe.

A challenge to all you lurkers. Name a make and model car that vents the fill vapors through the canister. All the tank systems that I have observed and researched vent the fill vapors back up the filler tube to be collected by the gas stations vapor recover system i.e. the bellows surrounding the nozzle. A lot of tank systems have a separate tube or hose, approximately 3/8 to 1/2 inch in diameter going from a high point on the tank to the upper end of the fill pipe. Also, most modern vehicle vapor recover systems have a pop off valve that allows pressure to build up in the tank before it is released to the recovery system. Ever notice the escape of vapor when taking the cap off on a warm day? Also the reason for the warning on the cap 'Remove Slowly". That pop off valve would force the vapors to counter flow up the filler pipe likely causing an early nozzle trip off.

So give me an education – help me understand this problem.

I see where you are going,you are challenging the idea that topping off forces gas into the charcol canister. I cannot provide the path you request. What we do have are those reports from the public and reported warnings from Dealers that the top-off practice hurts the canister. I will try a put some direction to this one way or the other.

I must confess I have been going along with the top-off warnings,Why? so many reports from the public on this Forum that canister replacement solved their problem

I agree that overfilling the tank risks pushing raw liquid fuel into the canister. What happens is that the tank is so full the normal thermal expansion raises the fuel level until the vapor recovery liquid separator becomes filled and liquid makes it to the vapor recovery line hence to the canister. Do you remember when vehicles had open vent tanks? When the tank was filled on a cool morning and the fuel warmed up on a hot day, gas would be dripping onto the road surface from the vent and/or the cap especially if the car was on a crowned road with the fill tube down. I remember that the sedans with the fill behind the license plate in the bumper were the worst offenders.

So far I have not read any feedback response that said that a canister replacement solved the filling problem. A lot of posters don’t share the solution once the problem is solved. So far I have not been faced with troubleshooting a ‘early click off problem’. When I do I will definitely share my troubleshooting tree; discovery; and solution.

Thanks for responding.

I had a GMC diesel van that got this way over time (and nearly 200K miles). There was a baffle or something that had been pushed away from the top of the filler neck by hundreds of nozzle uses so that fuel was being backed up to IT and causing the pump to click off. A stiff wire about a foot long bent with a 1/4" hook in the end pulled it back into place.

Problem solved.

20 seconds is a relatively long time. I havent seen but 1 in 10 gas nozzles that will run slow enough, on it’s low setting, for the 06 Escape and even my old 92 Explorer. They all just flow way too fast. I have to put my keys in under the arm to allow it to run until full. And there’s nothing wrong with the trucks, just the angles of the necks causing splash-back at such high flow rates as they are set for.

Well I actually have a Hyundai Elantra (2008). Shortly after I got it, at one gas station only, the pump would not stay on. I will say I live in New Jersey where it is full serve only by state law. I found one time at this particular gas station, the attendant turned the nozzle upside down, and it worked fine. However, now I don’t have this problem, as I don’t go to that gas station anymore since their prices are a little high compared to others in the area that give a discount if you pay cash.

Speaking of which, the attendant will try to get the amount to the nearest dollar sometimes, but more often now it seems like the nearest $0.25 of a dollar if paying cash, which I usually do since it’s cheaper.

“Speaking of which, the attendant will try to get the amount to the nearest dollar”

I also live in NJ, but I don’t wind up with an overfilled tank, simply because I get out of the car while the pump is running, so that I can be standing near the attendant when the pump clicks off. I simply announce, “That’s enough–No more” (or if the attendant is a limited-English hispanic person, I say, “Bastante–No mas”), and thus the pump is stopped at that point.

If the attendant is nowhere to be found when the pump clicks off, I simply take the nozzle out of the filler myself, push the button for “print receipt”, take my credit card and the receipt out of the pump, and I am on my way with the amount of gas that I wanted, rather than the amount that an attendant wanted to put into my tank.

At my usual Shell station, the attendants don’t even rush over to my car when the pump clicks off because they know that I will finish the task for them, and they seem to be as happy with my approach as I am.

So, MCPayne, even though you live in a “full-service” state, you can still take charge of the situation as I do, thereby preventing fuel system problems.

On Board Vehicle Recovery Systems were apparently phased in starting in 1998 and have been required on 100% of cars starting in 2000. They work by routing vapors pushed out of the gas tank by incoming fuel through the carbon cannister that was already there to handle fuel expansion on warm days. (I imagine that the go back up to the top of the filler pipe from there?) Trucks (and SUVs?) phased over on a more relaxed schedule. See


The EPA did acknowledge a decade ago that some pump nozzles were incompatible with ORVR. Surely that problem has been fixed by now? But perhaps an occasional pump/nozzle malfunctions such that it won’t fill some cars?

As to why cars from so many makers are reported to have these problems. I haven’t a clue. I have some doubts that topping off is always the problem. Maybe the cannisters/valves are just failure prone?

Blaming drivers/attendants for topping off? Some people are going to do that. My guess is that they will be prevented from doing so only by amputation of their arms/hands. Designing vehicles that won’t handle topping off seems to me like designing a car where the wheels fall off at 90mph. Ninety mph is above the legal speed limit almost everywhere, but that doesn’t mean that cars will never be driven that fast.

I live in NJ and I have a Hyundai Elantra that has the same problem. It started this past winter, the pump would shut off after a few seconds. I never topped off the tank though I can’t speak for the previous owner.

Finally have my Hyundai Elantra (2000)repaired just today.Could not put gas in the tank as the problem grew. I was one of the guilty one to top off the tank and I have now paid for that error. It was the carbon canister and the problem was worse than expected. It was explained that inside the canister is a filter type bag in which the carbon is enclosed. With over filling the carbon swells and after time breaks down and small pieces start to pass through the small holes in the carbon filler bag thus traveling to other parts of the fuel system, plugging other components along the way. Yes you guessed it this whole system had to be cleaned. All the lines were removed and purged as well as the fuel tanks. So no more topping up for me. In my defense though I do a lot of traveling so tried to get more gas in the tank for the long haul. Good luck to all the rest of you having trouble. Don’t top the tank or you will pay double.

Thanks for letting us know how it turned out. At least now you know. BTW everyone should read their owner’s manual and all those warring stickers and pay attention to them. It is cheaper and easier in the long run.