Bladder issues help!!!

If you want gas mileage help, please follow the directions at http://priuschat.com/forums/gen-ii-...-answer-these-questions-esp-if-youre-new.html so that we have more info to go on.

FWIW, Consumer Reports in their testing of the 2nd gen got 35 city/50 highway, 44 mpg overall. See http://web.archive.org/web/20080406...-advice/most-fuelefficient-cars-206/index.htm.

The "guess gauge" as many call it is just that. The amount you can go on a "full" tank before 1 pip goes down can vary a LOT, esp. if you go a bit and top it off. IIRC, I once went 160+ miles before a pip went down due a top off (fill tank, reset trip odomoter, go some distance, top it off, reset trip odo again, go 160 miles before it went down 1 pip).

As for the capacity of the tank... the most I've ever put in the tank of my 2nd gen was 9.975 gallons that was when I was down to a single pip.

When the pump stopped, did the gas gauge read full or did it not fill "completely"?

From your post, I don't think we have info to determine whether or not there is a problem w/the bladder or gauge calibration. Please let us know how many gallons go in at first (normal) shutoff when you're down to 1 or 2 pips. (Please don't push it too far at 1 pip. Get gas ASAP, at that point.) There could be a problem w/the inclination sensor, but we don't know yet.

 

The Guess Gauge gets confused on small (less than 4 gallons) fill ups. Could this be your problem? If you have filled the tank, use an estimate of 10g capacity (9g in cold weather) and your MFD MPG and distance traveled since the fill to calculate the fuel used. If your last pip starts to blink fill the tank immediately as running out of gas is NOT a good thing.

The bladder does increase the back pressure during fills (especially in cold weather). This can cause some pumps to shut off prematurely. It is likely that in your case you didn't get a complete fill.

These problems caused Toyota to eliminate the bladder in the 2010 Prius.

JeffD

 

I had a similar issue with my 09 - it just seemed like the gauge was not showing an accurate reading. It was showing as close to empty at about 50 miles and when I filled up it would take only about 7.5 gallons or so. Somewhere here is a guide to resetting the gas gauge - I tried it a bunch but it did not work.

So - I figured that I would run the car closer to what it should be reading and see if that reset the gauge. So once the gauge started flashing I popped a 2 gallon gas can in the back just in case. I drove about another 130 miles to the point where I figured that I would need a bit under 11 gallons of gas. It worked just fine and I was pretty close to my estimate.

The side product is that now my gas gauge is far more accurate - not perfect, but at least it is in the right ballpark now.

 

Five gallons is about exactly what I would expect in that situation. I put in about eight gallons if I'm down to one blinking pip. Keep in mind that the gross capacity of the tank is 11.9 gallons. The usable capacity is closer to ten gallons, and will vary depending on weather and the phase of the moon. All fuel tanks have some unusable volume, but in the case of the Gen II Prius it is exacerbated by the fuel tank bladder.

If you want to read about this in detail, search for "bladder" or "guess gauge".

Tom

 

Did you try topping off? Generally that's not recommended (don't want to get gas sloshing up the neck of the fuel tank, that can cause problems), but sometimes the gas station pumps click off too soon. Give it a couple more tanks to get used to it, then you'll be a little better at predicting if it's the pump's problem or not.
Generally I put in 8 gallons when it's down to 2 pips.

 

You probably didn't get a lemon, given you use the title "Bladder Issues" I can assume you are aware that Gen 2 Prius employ a expanding gas Bladder as opposed to a standard gas tank.

Very simply do a thread search. Some people, at different times of the year, in different conditions occasionally experience some difficulty in filling their gas bladder. In general it is highly recommended that you do not "push it", or try to top off as it can result in the bladder burping. This can lead to a whole new set of potentially more damaging and expensive problems.

There are some threads where people present various different approaches and methods as to refilling...turning the handle the other way, filling on the slowest setting the pump allows...etc, etc...I would just invite you to search, read and evaluate...

It was something inwhich that I paid particular attention as I live in Oregon where you can't pump your own gas. In general it doesn't appear to be a wide spread problem, it appears to only be an occasional or seasonal anomally. The "Guess Guage" is another but related issue.

The overriding general consensus seemed to be, if you have problems filling the bladder, DO NOT attempt to overfill or top off, and just fill as much as immediate mechanics allow. Try a different pump, level ground, or some different bladder fill techniques, but in general just keep as much gas as possible in your Prius, because even if you are not filling it to it's max reported "bladder" capacity, it's excellent gas mileage still offers good driving range.

It almost seemed like the occasional times people reported this problem dealing with it became more of just a function of familiarity with the vehicle and employing that with "doing your best".

I would say once you get use to your "Guess Guage" and quirks of your gas bladder it will become almost inmaterial.

Good Luck. Toyota abandoned the gas bladder in the 2010's, so I'd assume they were aware of the occasional problems the bladder created. That fact was a big reason I waited for the 2010's and passed on what were some fantastic deals on 2009's. But I sometimes regret that I didn't just get a new 2009 when the Toyota was offering good incentives.

In all my research, the occasional gas bladder issue and the guess guage, and some complaints about HID headlight function and cost to repair, were just about the only semi-consistent negatives inwhich I found. My evaluation was that ultimately that was pretty good for a automobile that employs as much technology as The Prius. No automobile is absolutely perfect, regardless of what advertising and automakers want you to think.

 

I fill my Prius at anything less than a half tank, and that translates to once a month. Asking how often people fill is kind of pointless, because it all depends on how much you drive, and how close you are to gas stations.

As for replacing the tank, it isn't practical.

Tom

 

The bladder helps keep emissions low. So to the extent you bought a Prius to make less impact, it helps.

I get 400 miles per tank in MS, when it is very warm 450. (my gas stations are 50 miles apart)

 

I wouldn't be worried about it. (I'm not worried about it on my own car). I fill up about every 350-400 miles. I've gone as far as 500 miles during a trip.

In college I had a car without a working gas gauge, so I just kept track of the miles and filled up about every 200 miles. Ever since then I've been tracking my mileage, although now it's to analyze my driving and see how to improve it, not out of necessity.

Do you smell a gas leak if you walk around it after it's been parked or after a trip? Might need to smell under the car or under the hood. You should be getting at least 40 mpg in a California spring unless you're taking short trips in that hilly area. But you really can't tell by the first tank, since you only drove for half that tank. On your next tank you'll have a better indication of your real mileage.

In good weather you should be able to go about 80 miles after a fill-up before the first pip disappears. If not, you're probably not filling up all the way (or getting really poor mileage). Try a different gas station/different pump, and see how it works that way. This could take some time to diagnose, but unless there's actually a gas leak, there's no real problem.

 

Again, I live in Oregon where you legally can't pump your own gas. So when I read about people occasionally having issues with the bladder it was a big deal to me.

What suprised me was I read about it here, but then out in the real world started asking people I saw in parking lots with Prius if they had experienced any problems with the gas bladder.

It kind of suprised me as almost everyone I asked either reportedly did not experience any problem and/or wasn't even aware they had a "Gas Bladder". I actually stopped asking people because I'd end up trying to explain to them about their gas bladder...and they would just give me this look like I had lost my mind...

If someone doesn't even know they have a expandable gas bladder as opposed to a regular "tank" try explaining that to them without sounding like a nut-case...I usually just said, "Have a Nice Day" then I would back away slowly....

Thanks to the existence and efforts of sites like Prius Chat I think the knowledge of Gas Bladders is becoming better known. I also know from my search and investigation that at the time, most Toyota salesmen either just didn't mention the gas bladder and/or really did not know themselves that gen 2 Prius has a bladder. So unfortunately it can become an issue new owners discover...after purchase.

 

I just filled up at 529 miles on the tank and the guess gauge had dropped to 1 pip in the last 20 miles. In the winter I sometimes only get 300-350 miles on a tank. Driving an average of 40-45 miles per day I fill up every 8 to 12 days. YMMV!

[edit]I put 9.2 gal. in the tank.[/edit]

 

The incomplete gas tank fill is a common problem, especially in California when the new vapor recovery nozzles were installed/mandated lin stations last year. The bladder design of the Gen. II tank exacerbates the problem. See the link below for a solution to the fill problem that has worked for me and others.

http://priuschat.com/forums/gen-ii-prius-main-forum/70844-tank-filling-drama-6.html

Also, keep in mind that the bladder design reduces the effective tank capacity to ~10 gallons. This is actually convenient, since the 10-pip display works out to one pip per gallon.

You might want to reset the fuel mileage indicator in the MFD so that you start with a "clean sheet of paper."

 

Except the first pip is generally closer to 2 gallons, at least in warm weather. In cold weather (freezing or below) it might be 1.5 gallons or less. The remaining pips are probably about .9 gallons each, but take that with a grain of salt. Maybe that's just my car.

It took me awhile to realize there were 10 pips, for some reason I thought there were 8 (the American system of dividing things into halves, quarters and 8ths, not into tenths).

 

If you're concerned about mileage, do be careful about what tires you pick. Some will have a significant negative impact on your mileage.

There are numerous threads at Gen II Prius Modifications - PriusChat Forums on tires. I was pointed to http://priuschat.com/forums/gen-ii-prius-modifications/20573-tire-upgrade.html when I first was in the market for replacements and put up my query at http://priuschat.com/forums/gen-ii-...-another-help-me-decide-tire-thread-06-a.html.

I ended up getting two Bridgestone Potenza RE960AS tires (same size as stock). When my other two Integrities get too worn, I'll probably get two more of the RE960AS tires.

Since you're in So Cal, you can probably go with summer tires rather than all-seasons. I fortunately got the above all-seasons as I ended up having to move from Nor Cal to WA and it snows up here some of the time. (Summer tires in snow can = BIG PROBLEMS.)

 

As a new Prius owner (bought an '06 about 10 days ago), I'm kind of embarrassed to admit that I didn't know about the fuel bladder until now. But it definitely explains the inconsistencies I've noticed in the rate at which the "pips" go away on my gas guage, and why I only got 158 miles (26.6 miles per gallon!) on the first half-tank of gas after I got it from the dealer.

Guess it's one more thing I'll have to get used to -- wouldn't have kept me from buying the car, but I'm glad I know about it now

 

Yeah, the dealer didn't give you a full tank probably.

 

That was my initial impression too...