Over 18 Gallons?!?
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Teching In
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Over 18 Gallons?!? How do I get over 18 gallons and frequently over 16 gallons when not empty in my 1997 Trans Am? Could someone have replaced it before or are gas pumps really that inaccurate?
The weird thing is the light was not even on so am wondering if my gauge is that out of whack that it will no longer light up and just be empty someday? I know it has the same problem as most where it is full for most of the capacity and then goes from full to empty in only a few gallons. And so, I usually don't go below 3/4 tank on the gauge due to this issue. But lately I have been pushing it...
Tim
The weird thing is the light was not even on so am wondering if my gauge is that out of whack that it will no longer light up and just be empty someday? I know it has the same problem as most where it is full for most of the capacity and then goes from full to empty in only a few gallons. And so, I usually don't go below 3/4 tank on the gauge due to this issue. But lately I have been pushing it...
Tim
TECH Junkie
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From: Western North Carolina
I doubt it is the gas stations. Those pumps are usually calibrated once per year at least. Obvious fuel gauge issues and you might be right about a gas tank replacement by a previous owner..
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From: PDX-OR-USA
if someone put a fuel cell in (They used to make sneeky ones that looked like stock tanks) its likely 20 to 22 gallons.
They were popular way back for showroom stock road race cars..
Isn't the gas warning light in that vintage of car just triggered in the gage itself?
They were popular way back for showroom stock road race cars..
Isn't the gas warning light in that vintage of car just triggered in the gage itself?
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From: Schiller Park, ILL Member: #317
Is all of this trouble at the same gas station or do you encounter this problem at any gas station?
Thread Starter
Teching In
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I think it has been at other stations because I often wonder how big the tank is, 17 or 18 gallons, but if 16.8 is the biggest, something is off...
Gauge light is just triggered by a level on the gauge itself as far as I know, however it doesn't blink on and off like you would expect when the needle floats around so am not sure...
Tim
Gauge light is just triggered by a level on the gauge itself as far as I know, however it doesn't blink on and off like you would expect when the needle floats around so am not sure...
Tim
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From: Schiller Park, ILL Member: #317
But that still doesn't explain how you're pumping 18 gallons into a tank that can't hold more than 16.8.
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Teching In
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Here it is again at a completely different gas station... I didn't have much gas to spare, my needle was between quarter and half gauge, which for my car means maybe a gallon left...
I thought the needle moving all over when low on gas was normal for all cars... I wouldn't exactly call this a "modern" car... some of the tech or parts were never changed from the 70s... a 5th gen f-body would be much more "modern"...
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Verdad Gallardo Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Regardless, the rapidly moving needle is not normal, or at least not how they were originally and when functioning properly. Not a single one of my 4th gens has ever done this, including my now 24 year old '98. But it's not an uncommon problem on various types of cars as they age (like I mentioned above, my '71 does this - but it really shouldn't either), could be either a problem with the gauge or wiring/sending unit that would likely cause this.
If sitting on a steep hill or a slope the needle on the gas gage's in my 99 T/A and 02 Z28 will move a little as gas tank shifts around due to the incline. Most noticeable under a ~1/3 of a tank or so.
My 72 vette the gas needle will move around a bit
Teching In
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From: Abilene, TX
I just sold my '97 SS yesterday and before he came to test drive it I thought I should add some fuel to it since my fuel level was about mid-way between 1/4 and E. I put 3 gallons in it and that put me just over 1/2 tank. I also own a '02 SS and it is crazy how the fuel level gauges work in the 4thgen cars. When filling them up they hang good on the full side but once you getting near 1/2 tank it drops like a rock.
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From: Schiller Park, ILL Member: #317
I don't think I've ever been able to put in more than 12-13 gallons when the needle was at 1/4 on my steel 15.5 gallon '98 tank, so at least 2-3 gallons still left at that point.
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From: Schiller Park, ILL Member: #317
Just thought I'd update this with solid, confirmed numbers. I ended up doing the annual refueling for my '98 last night, the needle was just slightly above 1/8 tank (so 3/16 I guess), and the car took 12.715 gallons. So there was still about 2.75 gallons of gas left in the tank, even at 3/16 needle position. And there was no float, shake, nor rapid movement from the needle even at this low position reading prior to refueling.
Teching In
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One thing I'll add to this discussion about fuel tank capacity, a 15.5 gallon tank capacity doesn't mean plum full coming out the filler neck/hole totals 15.5 gallons, it means 15.5 gallons is the safe full level in the tank, where the gas station pump would shut off automatically....the tank capacity is designed with extra capacity for expansion and proper return line/vapor/venting operations. Although it is tempting to "top-off" the tank full to the brim, it is actually not a good practice. Doing so, will not let your fuel return system work properly, put more strain on your fuel pump, ruin your vapor canister and evap system components. If a person is able to get 17+ gallons in a 15.5 gallon tank, they're definitely "manually topping-off" the gas! You'll get away with it, until you don't, when your vapor canister is full of gas for starters!!!
How do I get over 18 gallons and frequently over 16 gallons when not empty in my 1997 Trans Am? Could someone have replaced it before or are gas pumps really that inaccurate?
The weird thing is the light was not even on so am wondering if my gauge is that out of whack that it will no longer light up and just be empty someday? I know it has the same problem as most where it is full for most of the capacity and then goes from full to empty in only a few gallons. And so, I usually don't go below 3/4 tank on the gauge due to this issue. But lately I have been pushing it...
Tim
The weird thing is the light was not even on so am wondering if my gauge is that out of whack that it will no longer light up and just be empty someday? I know it has the same problem as most where it is full for most of the capacity and then goes from full to empty in only a few gallons. And so, I usually don't go below 3/4 tank on the gauge due to this issue. But lately I have been pushing it...
Tim
I would regularly fill up over 16 gallons. Sometimes 17 and 18 gallons, but usually on long highway runs and road trips where I would run into the "red" on the gauge where I knew my mileage and where I was consistently burning gas. (I could get nearly 30 mpg driving at 55 mph, so if I slowed down, I knew that I could go another 80-90 miles safetly when the check gaguges light came on.)
So, all of this should not be a worry in itself. However, if you are filling up at this level across multiple pumps/stations and your gauge is not in the red - then you probably have a problem.
If your gauge isn't in the red and you do not get the check gauges light, (and you are filling over 16 gallons) then you probably have an issue with your fuel level sensor.
If your gauge isn't in the red but you DO get the check gauges light, (and you are filling over 16 gallons) then the needle on your gauge cluster could be off.
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From: Wichita KS / Rancho San Diego
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Either way, something is definitely wrong with the OP's gauge if he's got a floating needle and only about 1 gallon of fuel left at the 1/3 tank mark, as he's stated above.
Joined: Nov 2003
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From: Wichita KS / Rancho San Diego
I've never tried to calculate how much fuel is actually left at the empty line - unlike my wife, who likes to test how far below empty the gauge will go with the car running.
My experience is the car will go about 40 miles between the1/4 line and the empty line. There may be a couple of gallons left on empty, but I don't want to test my luck all that much. I think the closest I've gotten on a fill-up is 15+ gallons. Close enough for me.