NO fix for Prius Gas Tank Filling Up Issues

Yes. One would have to be very "gentle" applying the air pressure and there would have to be a clear-cut way to measure any positive effect on the bladder. (?)

Guessing here: With the car turned off - just as when filling the tank, it would seem likely that the valves would be in the correct positions by default. But you are certainly right about potential damage.

Well, in my case, there must be room for the bladder to expand by roughly 4.5 gallons. That's not insignificant. I agree that the long term aspect of the exercise may be debatable. I do wonder what is the mechanism that, up until now, has reduced the tank volume by such a large amount. Summer and heat have arrived and, if flexibility is the only issue, I would have expected to see some measure of expansion by now, but there's been none. In fact, my last three fillups have been a consistent 7.4 gallons.

At this point, with no sign of input indicating that the process has been attempted, all we have is a thought exercise. I won't make my Prius the guinea pig!

Thanks, Tom, for your thoughts and cautions regarding the idea.

Paul

Hi All,

Actually, I think sucking any residual air out might be the solution. Because as the gas fills, some might get stuck in a portion of the bladder away from the filling tube. Kinda like air trapped in an underwater cave where the entry is lower than a portion of the cave.

This would explain while waiting and driving around fixes it. The gas sloshes back and forth, and the air buble gets moved over to the filler tube end of the bladder.

Sucking on a near empty tank would then pull most of the air out, which would then cause the bladder to be squeezed flat by the outside air pressure. When gas if pumped in, there is very little air space.

The only problem with this is how to suck on the filler tube without pulling out gas as well.

Maybe there is an air valve on the metal tank? Then one could hook up a foot pump to it, and open it. With the gas cap off, one would pump on the foot pump, pressurizing the metal tank, until gas comes up to the filler neck, but not out. Then turn off the valve and remove the pump. Put a pump nozzle in the filler neck, and slowly pump in gas as the valve is released. This fills the bladder with only gas.

Anyway, its a bit of guessing in this. There has to be a proceedure done at the factory to address this issue. I just wonder if it can be replcated in the field.

I have heard of that possibility. I have 20K+ miles on the odo and done this since day 1. As I have mentioned in another thread here, the fact that I have 20K+ miles and no problems, suggests that the problem is either rare or there is something about the way I'm doing it that is keeping it from happening. As always, YMMV.

Sorry you are dissatisfied with your Prius, but I'd like to help.
This car impresses me daily, and I want you to be delighted with your car as well.

As we all know the Prius gas tank is a little different. Here's how you handle it.

When you get gas Always reset your consumption display at each fill up. Also, Note # of gallon you pumped to fill up.

First, when it comes to range, the most important rule is:
You only have as much fuel in the tank as YOU'VE pumped in.
To figure your range, simply divide your average MPG into the miles you've driven since last fill-up.
When the figure approaches the gallon you pumped, it's time to fill-up.
Or another way...Multiply your average MPG, at any point, by the gallons you pumped, and that's your anticipated range. When you've driven your anticipated range, get gas.

When it comes to pumping gas into the Prius, there is something you should know.
There is a small rubber sealing ring inside the Prius' gas fill-pipe. It seems to cause the tank to pressurize when gas is being pumped and causes the "burp" many complain about.
To eliminate the "burp" or backflow of fuel during fill-up, always remove the pump nozzle from the car's fill-pipe for a few seconds, when the pump stops, before you try to pump some more.

Follow these steps to get the most out of your fuel tank:
Drive your car until the low fuel warning comes on, and go to gas station.
Reset consumption display.
Fill up on slowest pump setting. When pump stops, remove nozzle (for reason noted above) , then pump some more. Repeat until you've pumped 1.o more gallon.
I guanantee you've got at least 10 gallons of gas in the tank.
But to be safe, go drive until the low fuel warning comes on again, or you've driven 9x your average MPG since fill-up. If the latter occurred,
I guarantee it will take 9 gallons to fill up
Do it again, if the low fuel light doesn't come on, drive 9.5 x average, or 10 x, etc.
Whenever you fill up it will take that many gallons.
Reach the point where you are pumping 10-10.5 gallon at fill up and you've maximized your tank, with some reserve.

Now relax about the fuel tank, and lenjoy having the best car on the road.
Next, Learn to drive the car, to get the most efficientcy out of it. To maximize the time it spends on electric power. It's all in your right foot. Then, you can too can get at least 600 miles out of every tank like I do.

Does the 2005 have this issue? We have a 2005 and to my knowledge, this has never happened.

Yes, the US (NorthAmerican) Prius have the bladder gas tank. It's not an issue for me either, I had it "burp" once in the beginning and just slowed my pump rate and remove the nozzle sometimes as i describe in above thread.
I pump over 10 gallons everyfill up and drive over 600 miles/tank.

I drove my '08 off the lot a week ago today. I am having nothing but problems trying to put gas in. I have tried several stations in and out of town. I made a 450 mile round trip this weekend out of town and visited several different stations. Each time, I had the same problem. I am forced to try to get gas in by one little blip at a time. It will never stay on long enough to try to put it on the lowest setting. I barely pull the trigger and poof...off it goes. Additionally, after 840 miles of driving...the fuel guage has never had more than 1 pip off the screen. In other words, it has always showed me full even after 300+ miles of driving.

Obviously, some of you have not had this problem and continue to reply on this post as if the OP and the rest of us with this problem are idiots. Instead of adding to our frustration with comments like "I need data, perhaps you should simply add up the .127 gallons you get in with each blip and sit at the gas station for 3 hours. What is the big deal?"

Why don't the rest of you who don't experience this problem leave it to those who do to discuss? I have not found anything that works, but I am sure interested in hearing what people who have my same experience have been successful doing. I don't much care to hear from someone who has no problem at all as if it is because they are superior gas pumpers instead of just damn lucky.

I wonder if different areas of the country present more problems with Prius fueling. For example, where we live the gas pumps are fairly simple affairs, without any sort of vapor recovery. Other places use more complex pumps. Maybe we need a survey, but it will be hard to factor out Prius density for the various areas.

As for all of the potential Prius owners reading this thread and wondering if this will be a problem for them, I'll add my one data point: I've never had any trouble refilling my Prius. I insert the nozzle and set the rate at the lowest setting. When I get within a gallon of my expected fill I unclick from the auto-fill detent and go a little slower by hand. When the pump clicks off, I stop. The only reason I use manual fill for the end is because of problems I've had in the past with a previous car. Having the end fill under manual control lets me stop faster if there is a problem.

Tom

If you drove only 450 miles and made "several" stops for gas, how could you possibly expect to get much into the tank at each stop?
You haven't used much gas between stops. And thus the gas gauge wouldn't be showing much movement either. Run you car until you get the low fuel warning and then fill it up. See what'll go into it then

How are you getting such good milage? I live in Las Vegas and with the heat need the AC on, does that make that much differance? I am getting 39-42 MPG.

I made several stops to pump about .5 gallons at each since all of you superior gas pumpers claim the problem has to do with pumps. I decided to try out this theory by pulling off on several exits to see if different pumps would make a difference. Low and behold...it did not. It is a design flaw and for those of you who seem to think it is operator error, you can play hide the salami with your pet gerbil and leave this discussion to those of us dealing with the issue. Again, if you aren't having this issue...YOU ARE LUCKY...not smart.

After reading this thread several times I concluded that several different problems were being described. Some seemed to be gas gauge problems, some seemed to be gas tank / bladder problems, and at least one, ctsa, seemed to be both. Several posters blamed various pumps or nozzles while others felt the problems were overstated or "normal" for Prius fillup behavior.

My problem falls in with the majority where a fillup from virtual empty results in the gas gauge reading full but the gas pump reading substantially fewer gallons than expected. My car has had no other problems; no burping, no pump a gallon, rest, then pump again. I pump at the slowest rate and stop at the first click.

I do have an advantage which eliminates certain variables.(Or so I thought) I belong to a fuel distributorship and fill up at the same location and the same pump every time.

I resolved that on subsequent fillups, I would try using different combinations of suggested solutions hoping for improved results: Pump slow, pump fast, push nozzle in, pull nozzle out, etc.

Filling up during the warmest part of the day to soften the bladder would be my only constant.

~HOWEVER~

The Fates threw me a couple curves. When the gauge reached one pip remaining I headed for the pump at 3:00 in the afternoon. There was a car at the pump I usually use. I pulled around to the other pump. Expecting the normal 7.5 gallons fill, my first combination was to pump 5 gallons at top speed, with the nozzle pushed completely into the filler tube, hoping to expand the bladder, then stop, remove the nozzle most of the way and pump the remaining 2.5 gallons as slowly as possible. Surprise! For the first time EVER I pumped another 5 gallons into the tank for a total of 10.0.

I thought I had hit the right combination the first time. Much later, however, another variable occurred to me. All my previous fillups were from the pump where the car is facing slightly downhill, whereas the car was facing slightly uphill at the last fillup.

Obviously, most gas stations have a flat fillup area unlike mine, but the incline/decline factor may be significant when attempting to resolve a malfunctioning bladder problem. I don't know yet if that had anything to do with the improvement, or if it was due to any or all of the other elements of the combination. But at least for this fillup, I pumped a much better tankful.

Now I have a different problem. I drove 174 miles (at 62mpg) before the first pip disappeared.

Paul

We are having a simular problem with our 06, the first pip still being on and have about 180 miles on it now.
I'm a little worried that the sensor is broken. I'm getting 52mpg right now.

I think you have hit the majority of the problems on the head. This is mostly an issue of expectations, where the capacity of the Prius tank falls short of the published 11.9 gallons. If Toyota had listed the capacity as 10 gallons the problem wouldn't exist for most owners.

Tom

My comment was based solely on the posts within this thread. Perhaps you are making a broader reference. But that sounds as if your point is that misery loves company.

But it's not necessarily an unreasonable expectation. I'd be dissatisfied in the same way if my best FE was always substantially below the EPA ratings. At least with the FE, I could hope to improve my driving skills.

If only, if only. Not a compelling argument. No, as soon as some Prius owners began reporting 12 gallon fillups, while others got 7.5, there would be the same dissatisfaction.

Paul

Wow, that's great! The farthest I've driven on the first pip was 145 miles.

I always wait until the "Add Fuel" warning comes on. Then I fill up and usually get between 7 and 10 gallons. Lately, I've learned to drive my Prius by listening to it (using the force...) and altering my driving habits, and I've been getting over 400 miles on a tank, for the last 11 tanks, regardless of how many gallons the fill up was. The weather has probably had an influence on this as well. I have always just taken it on faith that the Prius warns me to add fuel, way in advance of actually needing it. I still believe that.

Regardless of whether my tank bladder is full or not (or whether it can ever be filled to capacity), I'm happy getting 400 plus miles out of 8 or 9 gallons.

http://www.autoshop101.com/forms/Hybrid13.pdf

Dave

These are the exact circumstances in which I would expect you to have a problem filling. The bladder will be collapsed to the maximum extent possible with air filling all the "wrinkles" in the top of the bladder.

As gas is added, even if added slowly, the bladder will re-expand unevenly trapping air. As the tank gets near full, either the air will stop the fill prematurely or it will be slightly pressurized and cause a burp. Your slow fill makes sure the burp doesn't happen. Then when you drive a while the fuel sloshing allows the trapped air to escape through the charcoal canister.

There is no real advantage to draining the tank. In fact, there are distinct disadvantages. I fill at between 350-400 miles (3 pips-ish) and have had only one problem that I've layed at the feet of an over eager full detector on the pump.