Ford Fiesta - Overfilling petrol tank?

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Wed 30 Sep 2020 23:37
Ford Fiesta - Overfilling petrol tank? - clappedout

What's the worst that could happen when you overfill your tank by a quid or two?

I know and have seen that in hot weather, fuel could expand and leak from the fuel inlet - which is obviously dangerous. I suppose with the cooler weather we're experiencing, that's not an issue?

Having realised that my tank was full, I went for a drive for 2 - 3 miles to burn some of it off. Do you think I've caused any immediate or long-term damage?

Also, would it be fine to leave it / parked up for the next two weeks if I don't plan on any journeys? Would there be a build up of fumes which may cause issues?

Edited by clappedout on 30/09/2020 at 23:40

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Thu 1 Oct 2020 00:09
Ford Fiesta - Overfilling petrol tank? - brum

Modern cars - not sure when this became madatory - are fitted with EVAP - Evaporation control and recovery systems. Their job is to stop, trap and recover fuel vapours from your tank rather than simply vent to atmosphere. If you overfill your tank past the click off point and start to fill the filler pipe, there is a chance neat fuel will fill the EVAP sys tem, cannister and purge valve and sensors. The cannister contains activated charcoal to trap fumes. The car emissions will be affected as the EVAP system often isnt capable of coping with this situation, you may have running or starting issues and quite likely the emissions or engine warning lights will come on.

It can be expensive to fix, over £100 sometimes much more.

Don't overfill a modern car!

Edited by brum on 01/10/2020 at 00:14

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Thu 1 Oct 2020 00:30
Ford Fiesta - Overfilling petrol tank? - clappedout

Thanks for the reply brum...

My car's definitely not a modern fiesta - wished it was.

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Thu 1 Oct 2020 17:38
Ford Fiesta - Overfilling petrol tank? - bathtub tom

I had a car with a large, flat, 16 gallon tank. The filler went into the back of the tank and the tank formed a triangle with the point at the front. One day a neighbour informed me petrol was pouring out of the filler cap. The sun was shining and the car was facing uphill on my drive. I assume an air bubble was created at the point of the tank, which expanded as the temperature rose, forcing patrol up the filler neck.

I now, never fill beyond the first 'click' and park!

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Sun 4 Oct 2020 23:12
Ford Fiesta - Overfilling petrol tank? - Big John

When I bought my current 2014 Superb mkII back in 2015 shortly afterwards I had a European trip. As I was driving near Luxembourg I filled up with very cheap petrol with many clicks to get the best value for money (Sorry - the Yorkshire effect). Some miles later my newly acquired car pinged up an engine management light. As my car was under warranty and I'd phoned my home dealer to ask what to do, I then visited a Skoda dealer in Germany. They were very thorough and checked everything and after a while the chief mechanic who didn't speak English (and my German is poor) came up to me and said "Von Klick - HALTE!!!". Fortunately I wasn't changed anything - the German dealership was incredibly friendly.

This I have done ever since and have had no further issues.

Edited by Big John on 04/10/2020 at 23:23

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Mon 5 Oct 2020 11:07
Ford Fiesta - Overfilling petrol tank? - FP

I have been brimming my 14-reg Mazda (petrol) ever since I got it several years ago.

No problems.

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Sun 22 Nov 2020 18:11
Ford Fiesta - Overfilling petrol tank? - clappedout

I've recently noticed that there is a loss of power when in 5th (and sometimes 4th) gear around 50 mph - stepping on accelerator has no effect and feels like car slows down a little.

Reading around, would this have anything to do with 'limp mode or boost leak' issues? I assume not as that relates to turbos - could be wrong.

Would my overfilling have had anything to do with this loss of power; which is intermittent and only when at or above 50 mph?

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Sun 22 Nov 2020 18:21
Ford Fiesta - Overfilling petrol tank? - Big John

Overfilling in the past will have nothing to do with this.

Limp home mode could be on any modern engine with electronic management (with or without turbo). It's where a fault is detected and the engine management restricts the power to avoid the potential of further damage or illegal emmisions etc. Usually the engine management light would the illuminate to flag that there is a problem.

Just out of interest when stepping on the accelerator at 50mph - does the engine rev up somewhat? If so it could be a slipping clutch.

PS How old is your Fiesta and what engine/gearbox does it have?

Edited by Big John on 22/11/2020 at 18:24

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Mon 23 Nov 2020 17:06
Ford Fiesta - Overfilling petrol tank? - clappedout

@Big John

I don't think it's the clutch as recently had that replaced.

It's a mk4 I think with 1.2 engine.

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Mon 23 Nov 2020 09:39
Ford Fiesta - Overfilling petrol tank? - Andrew-T

I have been brimming my 14-reg Mazda (petrol) ever since I got it several years ago.

I have never brimmed any car, for at least 40 years, for just these reasons. Perhaps because some of my early learning took place in the western States in the mid-60s, where it can get pretty hot, especially in places like Death Valley.

I don't mind stopping a bit more often for fuel, and I don't see the point of adding half an extra passenger in weight to the rear of the car. And I have other ways of monitoring consumption.

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Fri 27 Nov 2020 22:58
Ford Fiesta - Overfilling petrol tank? - Roland T

I've had several 1.25 Fiestas like yours.

I'm a serial topper offer and sometimes brimmer but have never noticed any detriment from doing so, other than wasting some of the extra petrol by parkig on a slope or via expansion on a hot day.

I wouldn't advocate it though. I recently changed the fuel pump on my '51 Fiesta and had to disconnect the evaporative emission canister from the back of the tank prior to doing so. Being level with the tank, it's hard to believe it doesn't get completely submurged if you brim the tank.

At that moment I decided I should stop topping off but just couldn't help myself rounding it up to the next whole pound the next time I filled up.........

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Sun 29 Nov 2020 01:53
Ford Fiesta - Overfilling petrol tank? - edlithgow

There's no evap cannister on my Daihatsu Skywing but some plumbing suggests it was originally fitted.

If the pump-pushing yoof overfilled (few DIY pumps in Taiwan) this plumbing leaked until I put a golf tee in it, so it would probably have wetted a cannister if there was one.

I took a cannister off an abandoned Toyota Corolla but havn't got around to trying to fit it.

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