Filling Petrol, Litre Is Counting but No Fuel Coming out. Possible?

Here's a weird one.

I recently went to BP refilling my tank that is still about 3/4 full since we're going on a long trip. Filled my car until the pump stopped, you know, the usual process. Total filled about 10 litres only. When we started moving, I noticed that the fuel indicator doesn't show full but remains at 3/4. I was like, weird, but thinking it's just hasn't moved yet for whatever reason. Turned out it wasn't stuck, the indicator goes down from that position along the way.

My question is, is it possible for a pump to not dispense fuel but still counting the litres? My fuel indicator is not faulty, after the trip, we did a re-fill at another servo and this time it moves to full. Appreciate if someone knows how the pump work and could tell me that it's physically not possible. At least it would ease my mind, otherwise I feel ripped off of 10 litres :/

Many thanks

Comments

  • +1

    I guess you need to fill up at a different servo to make sure your car gauge is not faulty for starters. Does it go all the way to full at all? Sure it went down but can you fill it to full?

    Do you mean you put in 10 litres, then the nozzle clicked to indicate its full but your car gauge only says 3/4 full? That can happen fairly easily for the nozzle click to go off prematurely… I usually do a second click to make sure after readjusting the nozzle position.

    As for whether a pump would tick over without dispensing fuel…. its possible if faulty but also unlikely…. Also most nozzles if you're paying any attention will vibrate with the flow of fuel so you can feel it going through. Were you not paying any attention?

    • +1

      Yes, as I mentioned, I filled it again after the trip and at that time it went to full as usual. I didn't do your second click method, but surely 10 litres is not an insignificant amount to not move the gauge at all? Nevertheless I will try your method from now on.

      The vibration, because of this case I will surely pay more attention. We did it so many times already so never realise if there's something off

      This article posted in a previous post here is not sparking confidence either

  • As you finish filling up, you will often realise a few drops of petrol still coming out of the nozzle. Did this happen when you filled up?

    • Sometimes. But this is another one that I never realise to purposely check, until this case. At that night, I'm not too sure if there's any dripping

  • +3

    The actual fuel measurement device is in the bowser, and the hose between this device and the nozzle should always be loaded with fuel. So when you start filling, you are getting the fuel in the hose and the meter is counting away, but that's as long as it always happens consistently.
    One possible outcome is that the hose was dead empty and the fuel measurement meter was ticking along just loading up the hose. This would seem unlikely and also would probably only be 1 or 2 litres, not 10 as you've described. This could occur if the person filling up before you had a trick to empty the hose for 'free fuel' or alternatively if the nozzle had leaked out onto the ground.

    Both seem very unlikely.

    • Thanks! never know that the measurement is in the bowser itself

  • +7

    Petrol stations face large fines for having fuel pumps even as much as 0.3% out of calibration. https://www.abc.net.au/news/2019-12-17/australian-petrol-bow…

    I'd hazard a guess and say maybe the pump clicked off early because when you put the fuel in it bubbled up causing a pressure spike and turning the pump off. And If you have a big enough tank 10L sometimes won't even make a dent on the fuel meter. My analogue indicator never really goes past 90% full even though the tank is.

    • Yeah this might be the reason or the combination of the previous comments, I have 60l tank.

      Appreciate your link

    • +1

      Yep early click off was exactly my thinking too. Some pumps are useless for it and start clicking after a couple litres so you have you hold the lever at 50% and it's fxxing annoyingly slow.

  • +1

    Kia Sportage by chance. Sometimes when I fill up from 1/2 the nozzle stops, and I drive away with the indicator on 3/4.

    • Have this exact car and never goes past 90% full for me.

    • Huh, looks like Kia Sportage has this common issue. Mine is a Peugeot 308

  • +4

    My question is, is it possible for a pump to not dispense fuel but still counting the litres?

    No.

    The hose will vibrate when the pump is working. The nozzle will only clicks when the safety is triggered.

    https://youtu.be/q3phjAQZdGg

    • Makes sense, thanks for the link

      So the click is only triggered because something blocks the sensing port. This is just my wild imagination, but can the bowser dispense air then? It will cause bubbles giving false indicator, given mine is already 3/4 full, but nothing actually comes in

    • -1

      That is an awesome video. I'm going to use that to send out to customers who always ask me how these work.

  • +1

    What car model?

    Some cars have carbon cannister issues which eventually deform the plastic fuel cell, reduce its capacity and give false level indications.

    • Peugeot 308. I know, not ozbargain choice of car :p

      • Petrol or diesel

        • +1

          It's diesel. Curious if it makes a difference? And I'm not sure why you are being negged above

          • @djprima: Negged because I spelt canister wrong or someone just has it in for me.

            Pretty sure only the petrol has carbon canister so unlikely to be your problem. I'll Google it later to confirm out of my own interest as well.

            • +1

              @Muzeeb: You are correct, no carbon canister on a diesel.

  • +3

    Diesel fuel can foam up causing the click off prematurely. This probably caused you to think the tank was full, but it wasn’t.

    Some premium diesels supposedly have anti foaming agents to help prevent it. Some pumps have higher flow rates designed for trucks that would make the foaming and splash-back worse meaning you won’t get as much in the tank because it clicks sooner.

    You should be able to feel the flow at the nozzle. It feels different to when nothing is flowing (after the click)

    Depending on your vehicle and gauge 10l might fill 3/4 of a tank or not make any difference to the needle position. My fuel gauge at present seems to move a lot slower between full and half than it does half to empty. Ie there is more fuel used in the first half of the gauge on the dash. If I put 10l in at 3/4 full it might not move enough to notice, but the distance I travel before i need to refill will Extend 100km or so (I don’t have a Distance to empty display.

    • move a lot slower between full and half than it does half to empty

      I could swear this is always the case in all cars, at least the ones I've filled. Perhaps it's by design.

      If only I could recall whether the nozzle is actually vibrating, I just remember the pump humming

  • +1

    We deal with a few fuel dispensing systems at work (mainly Gilbarco), and the error is usually in favour of the customer. Counters tend to fail in the way of "not counting" rather than over counting.

    Sometimes what can happen is the handle can get an auto cut off issue and shuts off early due to a few different reasons, so It may have given you the indication that you were necking the tank, but some odd direction or splash back was just causing the gun to shut off early.

    Edit: Just noticed you said it was a diesel, and what can happen is that diesel can foam up on filling the tank. This can also cause the gun to shut off much earlier than usual, as the gun cant tell the difference between fuel splash back or foaming fuel.

  • +1

    It is definitely possible. It happened to me at a pump in Melbourne, stood there while the counter went up to $20 then realised no fuel was coming out. I went inside to explain and they wouldn't believe me and insisted I pay.

    After arguing with them I had to basically drag the attendant outside and point the nozzle at them while holding the trigger before they would believe me.

  • +1

    It happened to me about 10 years ago. Price & litres was going up, paid for it and went back into car & noticed gauge was still empty. I had to refill.

    I can't remember if the bowser was vibrating or if it even clicked when finished.

  • +2

    It happened to me at a Caltex. I thought I filled the tank but the gauge didnt move afterwards. Turns out the fuel had run dry but everything seemed normal to me. Had to kick up a stink to get a refund.

  • Wow. Three examples in the last few posts. I guess I’ll be listening carefully from now on when I fill.

  • -1

    If the preselected amount is chosen this normally is the case

  • +1

    I've had it twice over the year. Where it said it filled up about half tank to my cars measurements. But was nowhere near that mark more like a quarter. Happened at a Liberty and United pumps. Had a friend fill up at a Caltex ages ago, said he filled over 85 litres on the pump. His tank was only 70. They do screw people over. You just wonder how much it's actually going on. Also if they're doing it to everyone, even half a litre over a full tank which no one will be able to tell the difference. No wonder people are wanting electric lol.

  • This is more common than I thought! Scary to think this might be one of the trick to get more revenue, I wonder if the audit date for each servo are public. At least we know which one has passed recently

    • I'm not sure who checks the calibration, but I remember seeing tags on the pump that show the last date it was done. Doesn't help much if the servo puts those on there themselves though..

  • Did you not hear the fuel running through the hose and into the tank?

    I've always heard it running when I fill up, and can usually hear it running up the neck, so can tell when the nozzle is about to click off.

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