1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Fuel Guage Problem

Discussion in 'Gen 2 Prius Technical Discussion' started by Redsixer, Oct 18, 2008.

  1. Redsixer

    Redsixer New Member

    Joined:
    Sep 27, 2008
    4
    1
    0
    Location:
    Oklahoma
    Vehicle:
    2008 Prius
    I filled up 2 days ago, and made a big mistake. I walked inside the store with the pump running. When I got back to my car there was a small puddle of gas under it from the gas overflowing. Obviously I did not have the nozzle in far enough and it did not shut off when it should. I have since drove a little over 150 miles and the fuel guage still reads full bars. Do I need to recalibrate it or could I have screwed something else up?
     
    TomIvicevich likes this.
  2. Ct. Ken V

    Ct. Ken V Active Member

    Joined:
    Oct 16, 2007
    535
    57
    0
    Location:
    Bolton,CT
    Vehicle:
    2005 Prius
    Redsixer,

    If you didn't immediately get any warning lights, then you may have gotten very lucky & not contaminated the gas tank part of the emissions system [which would have required the replacement of the entire fuel tank to the tune of around $400 (not sure if that amount is parts only or parts AND labor)].

    Since you got a very full filling, you may not see the 1st bar of the "guess" gage disappear until around 180 to 200 miles (or even higher---I think one poster recently reported his 1st bar didn't disappear for him until 203 miles). Please don't intentionally try to get a really full filling or next time you may not be so lucky & will have to pay for a tank replacement.

    Be aware now that with the colder temperatures coming that the internal bladder will be getting stiffer & may not expand all the way to the metal tank walls, so you won't get as full fillings as in the warmer weather when the bladder is softer. Therefore your 1st bar may disappear in as little as 50 miles, but it is unlikely that you will need a re-calibration for that case or what just happened to you. A re-calibration would be called for if you ran out of gas with 2 bars still showing on the gage (as one other poster recently had happen to him).

    Ken (in Bolton,Ct)
     
  3. PaulHS

    PaulHS Member

    Joined:
    Feb 6, 2008
    200
    19
    3
    Location:
    SE PA
    Vehicle:
    2007 Prius
    Model:
    N/A
    RedSixer,

    Most of what Ken has told you is accurate. However, the warning about contaminating the fuel system is somewhat overblown. Yes, it's better to be safe than sorry, but if the fuel system were really so sensitive, there would be reports of many, many fuel system repairs and replacements. Having to replace the fuel tank and/ or system is a worst-case scenario.

    The fuel system contains valves designed to safeguard itself in case of overfilling. These safeguards can be defeated however. According to Toyota documents, the greatest risk to the system will occur when deliberately attempting to "top off" the tank with the nozzle just barely past the filler tube seal.

    So, as long as you insert the nozzle correctly and stop when the pump clicks off, you should be fine. Your experience is not likely to be a problem, and may even be an indication that the system protected itself properly.

    BTW, I've had tanks where I drove 265 miles before the first pip disappeared. It's just not a goal to aim for. It's a Prius quirk.

    Hope this helps.
     
  4. qbee42

    qbee42 My other car is a boat

    Joined:
    Mar 2, 2006
    18,058
    3,074
    7
    Location:
    Northern Michigan
    Vehicle:
    2006 Prius
    The second question is whether you learned anything from this episode? :)

    Tom
     
  5. Fritzenheimer

    Fritzenheimer New Member

    Joined:
    Oct 14, 2008
    6
    0
    0
    Location:
    Atlanta, GA
    Vehicle:
    2008 Prius
    Redsixer,

    I'm a newbie like you and had the same problem. After the spillover incident we drove at least 203 miles with the gauge reading full. No warning lights or indications of any problems, but the gauge was wierd. At 300+ miles it only showed -1 pip. Concerned that the gauge was not working I took it in to the dealer. They reset the inclinator and it dropped one pip. At 365 miles it still read only -3 pips. I put gas in and it took 5.2 gallons.

    I wouldn't fret about it. I've learned that the gas gauge just isn't a reliable indicator. As others have said fill up before you get down to the last 2 pips or you may find yourself out of gas.
     
  6. N3FOL

    N3FOL Member

    Joined:
    Dec 2, 2007
    891
    16
    0
    Location:
    Stewartstown, PA.
    Vehicle:
    2008 Prius
    In most states it is unlawful to leave the pump while filling with gas. As mentioned before, you are lucky that nothing got damaged just a few cents of wasted gasoline on the ground. On my previous non-hybrid vehicles I am always at a habit to fill the gas tank up to the brim until I read threads in this forum to safeguard my Prius.

    Drive safe.
     
  7. qbee42

    qbee42 My other car is a boat

    Joined:
    Mar 2, 2006
    18,058
    3,074
    7
    Location:
    Northern Michigan
    Vehicle:
    2006 Prius
    In Michigan there are signs at the pump that state: "...must stay in attendance and in view of the nozzle." From that I understand that I am supposed to stay with the car during refueling, but I've never been able to understand how I can stay in view of the nozzle. First, I'm not sure that nozzles can see, and second, if they can see, once I shove the nozzle's little head down the filler neck, I know it can't see me.

    :D

    Tom
     
  8. Fraser

    Fraser New Member

    Joined:
    May 9, 2008
    667
    9
    1
    Location:
    Navarre, Florida
    Vehicle:
    2008 Prius
    The first several fills, I trickled in gas until it was really full. First pip dropped at 170-200 miles. But being warned about possible damage to fuel components. I've started pushing gas through full bore, letting up the last half gallon or so. Since then, first pip has dropped at 130-140. MPG is pretty consistent at 49-51. And we get at least 400 miles on a tank.
     
  9. richard schumacher

    richard schumacher shortbus driver

    Joined:
    Mar 27, 2004
    7,663
    1,038
    0
    Location:
    United States
    Vehicle:
    2004 Prius
    Model:
    N/A
    It is dangerous to walk away from a running pump. There is the possibility of no shutoff and spilled gas, obviously, but also: if you walk away you may do something to create a static charge on yourself, which you may then discharge near the fill pipe when you return. This can start a fire. See for example: [ame=http://www.youtube.com/watch?v=b3x-8tj49ac]YouTube - Gas Pump Fire[/ame]
     
  10. Redsixer

    Redsixer New Member

    Joined:
    Sep 27, 2008
    4
    1
    0
    Location:
    Oklahoma
    Vehicle:
    2008 Prius
    Yeah I definately wont be leaving the pump unattended anymore.
    After around 220 miles the pips started to decline, so everything is good.
     
  11. Rest

    Rest Active Member

    Joined:
    Aug 13, 2005
    1,210
    53
    2
    Location:
    CA
    Vehicle:
    2007 Prius
    Why do people insist on letting go of the pump handle and then sit in their vehicle? Static electricity.....it will kill ya!
     
  12. bluesman2007

    bluesman2007 Junior Member

    Joined:
    Aug 23, 2007
    27
    0
    0
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Recently took a trip to Las Cruces from OKC which I've made before and was able to make it to Tucumcari on a tank with some to spare (3 bars)...this time I was at 1 bar about 30 miles before the last stop. I figured I was about out of gas by the time I found a station. I put in 8.5 gallons and got 41mpg.
    Don't want to run that scenario again...I thought I'd have put more in the tank....hmmm

    Had a nasty head wind so I figure that was the reason I got less than the previous 45mpg.

    The rest of the trip was pretty good, 46.3, 50.2, and 45.4 (the last was the same stretch that I got 41 going to NM)
     
  13. bwilson4web

    bwilson4web BMW i3 and Model 3

    Joined:
    Nov 25, 2005
    27,396
    15,518
    0
    Location:
    Huntsville AL
    Vehicle:
    2018 Tesla Model 3
    Model:
    Prime Plus


    I noticed that my "low fuel" alarm has been coming on when I was only down about 9 gallons. So I deliberately ran out of gas with a 1 gallon, spare can in the trunk. It took 135 miles before the ICE ran out.

    After putting in my spare can gallon, I filled up and the total came to 11.3 gallons including the spare can. This pretty well matches what I've seen in the past, ~0.5 gallons unusable.

    If this works as expected, my next "low fuel" warning should come with about 10+ gallons of empty tank to fill.

    Bob Wilson