Faults

Can an overfull gas tank cause engine problems?

For some reason the gas nozzle failed to "click off" when filling my gas tank tonight resulting in gas spilled all over the side of the car and the ground. Not thinking too much of it (bad move it seems), I put the cap on and started to drive off. After driving about 50 feet, the check engine light came on and the car stalled. The car would then not start until I let it sit for a bit. Then it started weakly while giving it a little gas and I was able to drive another 10 feet before it stalled. I syphoned some gas out of the tank (by mouth) but with no better result. The car has never had such problems before, its a 1999 Audi A4. Could this be the result of too much gas in the tank or is this some strange coincidence? Thanks!

Public Comments

There needs to be about 5% space in the tank for vapor expansion. If gas is spillinjg out you need to remove more than a gallon of gas then shake the car like crazy & hope it starts. Maybee once u get some more gas out leave the cap off for a bit to help the vapors expand. Stay away from open flames while doing this!
it is possible for too much gas to mess the car up. try driving it with the gas cap off for a little bit. and if you syphon gas out, you're gonna have to take out a couple gallons for it to make difference. hope this helps.
It's a strange coincidence. I always fill my tank as high as I can, its that extra half gallon, that saves me a few dollars the next time, when gas is 12 cents a gallon more. It could be though, that something did happen in your gas tank, that would cause the failure of the auto stop device, but the overfill of fuel is not the cause of your dilemma. I'd guess fuel pump, or some other form of fuel delivery. It could be that the piece that caused the auto stop to engage, broke off (i don't know if that's even possible, or how it even tells the pump to stop) and is now in your fuel line. I'd have a shop check it out. The check engine light is on for a reason, and it usually means problems. But your overfilling the tank is certainly not a cause. I had this happen to me once too. I was on the way to a college final, the auto stop didn't work, and I had to go to my final, smelling of gas, My jeans were trash, and my skin tingled and burned most of the rest of the day. When I was done with my finals, it took two 30 minute showers to get rid of the burning, itching sensation of the fuel. Again, I had this happen to me, and my car didn't break down. I've done it in a 1978 Datsun 510, 2005 Kia Rio, 1989 Toyota Corolla, 1986 Nissan Sentra, 1988 Honda Civic, 2007 Nissan Sentra, 2004 Hyundai Elantra. Not all were mine, but I was responsible for filling up, and all were "overfilled". All "overfilling" or "topping off" does is give you that little bit of extra gas at $3.20 a gallon, so that when you go fill it again at $3.35 a gallon (thanks Washington state taxes btw, gotta love 'em), you just saved a little money by getting that extra 20-40 miles at 3.20 a gallon, rather than paying for them at $3.28 a gallon. Yeah, you save 8 cents right away, a few bucks the next time you fill up, but you figure you save what you'd pay for a gallon of gas in a week (we'll average it to $3 a gallon) that's $156 a year you save, hey, that's a month's car insurance, yipee. Those of you who don't have an accident and 6 violations, it's about 4-6 months, lucky duckies. I know I ranted a little, sorry, I just like to be thorough. But to answer your question bluntly, no it doesn't hurt the engine, yes, it was a coincidence, I can tell you this based on personal experience. However, it is possibly your luxury car maker decided to be redundant, have a reason for you to pay $6000 more for basically the same thing, and put in a $5 part that makes it a bad idea to overfill the tank.
Not as long as you stay clear of fire. Give up smoking!!! at the price of gas, you didn't think to much of it spilling all over the side of your car?? I want to walk behind you when you cash your check. You say the car stalled, wonder where that extra gas went????? very interesting, O highly flamable one.
Topping off the tank can cause flooding of the charcoal cannister, an emission control in the engine bay. You need to get the fault codes read.