NO fix for Prius Gas Tank Filling Up Issues

Well I guess this is as good a place as any to introduce myself. I just bought a 2008 Prius, broke it in and took it on its first 2,000 mile trip. I drove from Idaho to Lincoln, Nebraska, then up through the Black Hills of South Dakota and back to Idaho. It now has about 2,700 miles on it.

As with others in this thread, the last three fillups on my trip caused me a lot of headache. It started out by just being difficult. I had to pump in the gas very slowly to keep the nozzle from clicking off. On the next fillup, I did the same, but this time when I removed the nozzle, about a quart of fuel came squirting out. Yikes! Then the last fillup, It seemed to take the fuel a little better, then clicked off after a few gallons. I had driven almost 400 miles on that tank so I put more fuel in ... slowly. Then it started to run out on the ground. When I pulled the nozzle out, I lost about a half gallon. That hurts when it costs over 4 bucks a gallon. Not to mention the damage the fuel might cause to the paint and tire. It is possible that the slow filling allows you to overfill the tank, but I had to go slow to avoid the nozzle clicking off. Quite a dilemma.

It seems others (7 pages worth) are having the same issue.

One other thing (nothing to do with fuel), my Prius gets thrown about quite badly by stiff crosswinds. Is it just me? I can feel the wind in my other vehicles, but the Prius moves quite a bit more. Almost scary more.

I feel like I want to write a complete review of my experiences with the car. I have driven almost every condition imagineable (except snow). I am not all that impressed with the 9 speaker JBL system. Where's the subwoofer for heaven's sake. Also, another 12V outlet a little closer to the drivier's seat would be nice.

I also ran out of batteries up a very steep mountain pass in Wyoming. Then charged them to capacity and wasted some energy coming back down (the batteries were full). I will say the car is quite underpowered without assistance from the electric motor (when the battery was dead). I went to pass a slow moving motorhome, and ... nothing. I could not gain one mile per hour. The motor wound higher, but the speed remained the same. By contrast, however, I will say the car accelerates surprisingly well when there is power for the electric motor.

For the 2,000 mile trip, I averaged about 48 MPG, which is even better than I expected. I am very pleased about that. My best tank was 52 MPG!

Since I said some bad things about my Prius, I should balance that by saying I love my Prius. It is the car that will change all cars to come. It has an amazing level of intelligence and is full of "why don't all cars have this" features. It gets astounding fuel economy and requires almost nothing from the driver. It takes energy normally wasted as heat and stores it to get you up the next hill. And the touch screen controls and cupholders are cool.

Mike

 

Your comments are not unique, and have been addressed many times here on PC. A google search on priuschat.com is your ticket to all of this information, if you are interested.

Tom

 

I have had a unique experience with my gas tank/gas gauge. I was traveling and had gone about 300 miles (started off with full tank just pumped that morning) and had just moved down to 3 pips on my gas gauge. All of a sudden, I got the dreaded triangle and a couple of other warning lights and basically the car "died" on me on the highway. I was able to coast off at the next exit and into a DPS parking lot where I proceeded to call my Toyota. They referred me to the Toyota dealership close to where I was. Long story short, they towed me in and had a quick look, said my tank had run out of gas and reset everything (I was unaware of this) and recharged my battery and sent me on my way. I was baffled since I had only driven just under 300 miles and according to my gas gauge, previous driving and what I "should" have had left, I had 3 pips left or just around 150-200 miles left.

I took my car in to my dealership when I returned from my trip for a checkup and to investigate further what had happened. They told me that the other dealership had reset the codes so there was no way for them to read what might have happened. Since running out of gas (imagine that!) is not covered under warranty, I had to pay for other dealership service instead of warranty.

I had pumped a full tank of gas and knew how much I had put in. I should not have been out of gas. No way to prove it and has had me worried about running out of gas since then. The advice I was given was to just fill up every 200 miles. Sure, but that isn't why I purchased the Pruis. Not to mention, that could mean every other day going to the gas station. Again, not why I purchased my car.

I also have had 2 different instances where I tried to fill up the car on the last pip and it wouldn't accept over 1 gallon at the time.

At that aside, I love my car! Went to the dealership with my husband so he could get a Yaris to supplement his PT gas guzzler Cruiser and they kept wanting to buy mine back from me. Never in a million years!

 

I've had my 2008 Prius for about 3 months now and have filled it up 5 times now. Each of the 5 times I've had trouble with the pump clicking off after only filling it with 5 or 6 gallons of gas. I've waited until the gas gauge was down to the last bar and twice it was flashing. I talked with the dealer and was told it's "normal" and to try and put the gas in slower. I've tried that and tried different stations, but it always does the same thing. I've had 1 instance where it clicked off after the 1st gallon (it had only 1 bars of gas left on the gauge at the time).

It's really frustrating trying to get gas in this car. Aside from this annoyance, I love it. I guess I'm just really surprised that a Toyota vehicle would act this way, considering how well thought-out everything else on the car seems to be. About the only thing I've found that allows me to get anywhere close to 10 gallons in the tank is to barely have the nossle in the car and you can hear what sounds like air escaping around the nossle. The only problem with this is that the pump doesn't click off when it does reach full and it usually burps and pushes gas out.

 

Haven't had the opportunity to fill mine yet, so this thread has been educational. One thing I intend to do (and suggest to those who are having trouble) it to fill it with the fuel door on the up side of any slope (true flat landers need not worry about this.)

This is what I've always done with other vehicles as well, this way I get the max fill in and less variability. I look to see what pumps are open before I pull into a station, if my fill door is going to face downslope I keep going to the next station. (When I've had to fill on reverse slope the variability is usually north of 10%.) I do not try to top off (unless the pump kicked out early due to someone else's diddling with their nozzles--happens frequently enough.)

With a bladder and the potential for air pockets I want trapped air to have a natural high path out as the tank fills. That and letting the tank vent a little near the end seem to make sense.

Think about filling any bladder type container, you want the neck pointed vertical and the bladder "hanging" as freely as you can below. Any trapped air pockets must be able to vent upward during the fill.

Does anyone have detailed 3d drawings of the system for visualization? I'm accustomed to having detailed drawings for writing fill and bleed procedures. I hate guessing. I really need to know specifically what the geometry looks like before I determine what is the optimum fill angle.

I can see why cold weather could be a problem because the stiffer bladder might not expand as it should, but hot weather should only result in excess venting during the fill.

p.s. On the other end of the spectrum, I had a car that the dealer fouled up the fuel pump in (screwing with the wrong parts because they were incompetent.) When I made the mechanic reinstall it he must have positioned it differently as the tank became more sensitive to low fuel levels. Facing uphill, accelerating rapidly, or cornering sharply in one direction would starve the car for gas at about 1/8th tank. It still had plenty of gas in it, but I had to be careful how I parked it. (Never ran it out of gas.) About a year later the fuel pump went out...no doubt because of the idiots at the dealership messing with it and half a dozen other parts that were not the problem at the time.

 

The genIII Prius will likely have a bladderless fuel tank like the TCH.
The bladder was used to minimize gas vapor emission during refueling when the gas cap is remove. The bladder eliminates air in the tank so gas vapor cannot accumulate.

The TCH uses a vacuum pump to purge the vapor in the tank when the gas cap opening button is push. It will take about a minute before gas cap cover will open.

The bladder is not a faulty design but it posts a problem with cold weather and overly sensitive gas nozzle shut down mechanism. There is no way for Toyota to fix this without retrofitting the Prius bladder gas tank with the TCH purging system.

 

Try these.

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

http://priuschat.com/forums/prius-technical-discussion/30593-gas-bladder-exposed.html

Note that there is already a valve at the top center of the bladder, so you shouldn't need the filler neck to release trapped air.

 

Danny,

Thanks for that! This is even more complex than I hoped, so I'm going to have to cogitate on it for awhile. The system looks over-engineered to me and therefore prone to being fussy.

The vapor return/vent lines look too small, particularly with so many valves and fittings (hence the need for slow fill rates?) If liquid gets into some of those lines it could create a seal leg, etc. It's interesting that Toyota is relying on a nozzle seal to "improve bladder expansion with gas pump pressure."

I don't trust that center bladder vent to work as it is sitting atop a flexible bladder. I don't see enough elevation difference to be certain vapor won't become trapped elsewhere along a ridge or corner while liquid is forced into the central vent. During normal operation it should be okay for providing level. It probably won't give you an instantaneous level indication. (I'm assuming there is time averaging to level indication anyway, as in my other Toyota--it reads a little high after driving, and low on start up.) If it provided an instantaneous high level indication upon start up (but you know it took too little fuel) then you would know that the vent line to level reservoir and such had flooded stopping the fill.

So much for hoping for an easy answer...

 

Err,

The 2007 TCH the manual states that it may take UP TO 10 seconds for the fuel door to open, depending on the fuel tank internal pressure. Mine has always opened immediately.

If you have a TCH, does yours take about a minute to open? Or are you referring to the upcoming GEN III Prius?

 

I have a 2008 Prius and itI has only happened to me once. The tank was down to the last two pips and I could only put 3 gallons in, but I knew I could get home with that much gas. My solution is to go between 250 to 275 and fill up. It usually takes 5 gallons and works for me.

 

I have had my car for about a month now and just had a problem with this yesterday. I think it was something I did, though. My first 2 or 3 fillups were fine, filled to the rim. This time, though, I had two gas gift cards from work, one $25 and one $50. I decided to use the $25 one first and discard it then the $50 one. So I filled up to $25, and at a few cents before it slowed down and stopped on it's own to $25. Then I couldn't figure out how to keep filling it up using a different form of payment, so I took the nozzle out, printed a receipt, then started over. When I put the nozzle back in and started to use the $50 card, it got to 94 cents then shut off. $25.94 nowhere nearly fills up my car at $4.11 a gallon. I had arrived at the station with one pip so it should have been around $40/$45 or so. After it shut off I tried a few more times to get it going and it kept clicking off. Remembering this thread I gave up and pulled the nozzle out.

When I started the car it "filled up" to full minus one pip. VERY OBVIOUSLY not accurate. I have since driven 75 miles and am now down to half a tank, in one day. Again obviously not accurate.

I think me somehow stopping the nozzle, pulling it out, and putting it back, created an air pocket or something making the the nozzle think the tank was full. Then when I started driving the air pockets dissipated and I lost the pips fast.

I am anxious to use up the rest of this half a tank and fill up again, this time without stopping, to see if it happens again. I hope not. My previous flawless fillups give me hope. I'm anxious though.

 

I have a few questions about your previous "flawless" fill-ups...

How many gallons did you pump during those fill-ups?
How many miles did you drive between those fill-ups?
How many miles did you drive between the last "flawless" fill-up and that recent problem fill-up.
If you simply note how many miles you drove since last fill-up and divide it by the average MPG since that fill-up, the result will be how may gallons you used, and thus, can expect to pump.

The exact amount of fuel goes into my tank, after the exact same amount of miles have been driven/ average MPG, every single time. And it will in your tank too. You gotta have a baseline and drive it down to the low-fuel warning at least once. The PIPs are not that accurate, but quantity and burn are.

Expressing gas pumped in Dollar figures is pointless. A statement like "$40-$45 or so" can be a variance of 1.4 gallons or so.
That's a big variance in a 10.5-11 gallon usable tank.

 

Yes, all the time, and by running the numbers I know the range of every tank. I suggest you run a tank down to at least the low fuel warning and try to start establishing a baseline like you suggest. It will fix the problem.

 

I just fueled up my 2008 Prius. The nozzle stopped 5-6 times. I pulled it further out and it seemed to fill ok, but when it finally did shut off, the gas boiled out all over the place. It took about 5 gallons. When I started up, the gas gauge was stuck on 1/2 full; same as when I started. After a few minutes it went to full. The mileage did not reset on the "consumption" screen.

 

Lean in here a little closer. Still closer. Okay :fish:

The nozzle stopped because the tank was full. That's how they work. Pulling it out allowed you to overfill the tank, which is not something you want to do. The gas gauge was not "stuck" at 1/2 full - there is a time averaging function that slows down the gauge response to keep it from going up and down as you go around corners and change speeds. Slowly rising to full is how it is supposed to work. Lastly, the mileage does not automatically reset when you fill the tank. You have to press the reset button for that.

The owners manual is a great place to find this sort of information.

Tom

 

I have an "05 and if I put more than 6 gallons in the tank...the mileage atuomatically resets.

 

It seems like everyone likes to fill up at two pips or two bars as I call it. Does the gas pump symbol come on in the 08. I have less than 1000 miles on my car.

 

Have you tried this? Bounce rear of car, hard, sloshing gas in bladder, with tank cap off, open to outside air? I had the same problem month ago. Tank gauge showed empty. No matter what, could only get 2.5-gallons in it. Handle clicked off. Drove about 50-miles to another gas station. Openned tank cap, pressed down on back of car to give a good up and down motion a few times. Got about 6-gallons in it. Day or two later, car filled up normally. Seems bouncing back of car, sloshing tank real good, with gas cap off, open to outside air, worked.

My problem happened to me when coming down out of the mountains, changing bearametric pressure, as in ears popping. Hard driving (fast) for about 4-hours straight. I gaffed it off to unequel pressures.

Now, I may have also jinxed myself. My next comment may be how it has happenned again, since I have now wrote that bouncing seemed to fix it. Wooeeessss Meeeee.

 

I will add my story. I just bought a 2009 a couple of weeks ago. First fill up was with 3 pips left and I got a little over 7 gallons in the tank. Today I tried to fill up with 2 pips left and the pump shut off before I even hit 5 gallons. Each time I tried to resume pumping it immediately would cut off as if it was full. I got it to 5 gallons and gave up. As I drove away the fuel gage went up to full and a few seconds later it dropped down to one pip over half.

So, either the bladder really was full at the time (for whatever reason) and when I drove away the movement allowed it to expand or the pump was too sensitive and thought the tank was full before it really was. I'm sure there are other possibilites but those seem like the most probable causes.

Not looking for any help as I think pretty much everything has been covered in this thread already. Just wanted to say I share everyone's frustrations, especially as my wife was really looking forward to less frequent stops at the gas station.

 

This just happened to me this week for the first time with my 08 Prius at around 9,200 miles on the odo.. Tried to fill up with 2 pips at a Shell station. With 2 pips, I can get at least 7.5 or 8 gallons in to fill it up. It stopped at 4 gallons, and I struggled to get 5 gallons in. I guess I wll just keep filling up at 2 pips to be safe.