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Q: When refilling gas tank, gas overflows before tank is full.

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Often times, as I'm pumping gas, the pump will shut off because the end of the nozzle touches gasoline. I then see gas flowing out of the tank, so I stop. I then get back into my car only to find my gas gauge reads half a tank. I know it is not a problem with the gas gauge as I know about how much driving gets me to empty and I know how many gallons of gas my tank holds. I first noticed this during a long trip. I recently took another, and now it is happening again. It doesn't always happen, but it's a major issue and I can't seem to diagnose the problem. Thank you for your time.

My car has 65000 miles.
My car has a manual transmission.

The most common cause of this type of problem is when the fuel filler neck’s inner tube comes off of the neck itself. You will need to have the filler neck removed to check to see if the inner tube was knocked off from someone trying to get fuel out of tank with a siphon hose and managed to knock the hose off. This causes the tank to not get filled properly and the inner hose can get caught in the fuel sender causing wrong readings.

If you’d like to get this fixed, consider YourMechanic, as a certified technician can help you service your fuel filler neck and ensure that your fuel gauge functions normally. Good luck.

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