What's up with Lottie's slow fill-ups? Find out the cause.

Dear Car Talk

Dear Car Talk | Jun 01, 2007

Dear Tom and Ray:

I have a 1998 Nissan Altima, and every time I put gas in the car, the nozzle clicks off, or the gas splashes back out like it's full. What is causing this? It is so irritating! I have to pump gas into the car very slowly, then stop and wait, and then slowly pump some more. When it's cold outside, I freeze while putting gas into this car. I have taken it to the dealer and they said they didn't find anything wrong with it! DUH! I know there is something wrong when it takes me more than 10 minutes to pump $10 worth of gas into the car. It does it every time. Please help me. What do you think the problem is? -- Lottie

RAY: Gee, I don't know, Lottie. I don't see any problem. Do you, Tom?

TOM: Of course there's a problem, Lottie. We just got a letter from some poor bloke who must have pulled in behind you at the pumps. He complained that he had to stew for 10 minutes while waiting for "some gal in an Altima to figure out how to pump gas."

RAY: This condition is probably caused by either a blockage in your gasoline vapor recovery lines or a bad refueling control valve.

TOM: Gasoline vaporizes. How do we know that? Well, when gasoline is spilled, you can smell it, right? What you're smelling is vaporized gasoline.

RAY: And in the old days, when you filled up your tank, all the air inside the tank -- the air filled with gasoline vapors -- came whooshing out through the filler hole or through a vent at the top of the gas tank.

TOM: But then people in places like Los Angeles realized they couldn't see the person standing next to them due to smog. And since gasoline vapors contribute to smog, car makers were forced to install devices to capture those vapors.

RAY: So now each car has a vapor recovery unit that collects the gasoline vapors from the tank and then, the next time the car is started, sends them to the engine, where they're combusted. Your vapor recovery system isn't working, Lottie. One possibility is that one of the rubber hoses is blocked or collapsed.

TOM: Why does that keep you from filling your gas tank? Well, when the air (and the vapors) can't get out of the tank, there's no room for gasoline to go in.

RAY: The other possibility is that one of the valves involved in the refueling process (the refueling control valve, the refueling EVAP vapor-cut valve or the one-way fuel valve) is not working.

TOM: In any case, you should go back to your dealership -- or maybe find a different dealership that cares a little more -- and tell them there's a technical service bulletin that explains how to fix this. Have them look it up under "slow fuel fill." Or you can invest in some nice, fur-lined gloves and a parka before next winter, Lottie. Good luck.

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