HELP! My gas gauge is suddenly demon possessed!

Hello all! It has been awhile since I've posted. I still have my 2007 Prius, now with about 183k miles. Suddenly, my gas gauge is all wonky. I never let it go below 3 bars. Last week because of the hurricane, (which for us was nothing), I MIGHT have overfilled it. I am not sure. A few days later, it was down to about 1/2 a tank, no problem. The next day however, it went from a 1/2 a tank to ONE bar. No evidence of any gas leaking. I went to fill it up and it only took like 4 gallons to fill it.

This was 2 days ago. I drove it maybe 120 miles yesterday and I think it showed only one bar down. Today we drove the car about 60 miles and it showed ONE bar blinking! We went to the gas station and refilled the tank and it took 5 gallons.....so it clearly was NOT at one bar.

So...my question is, 1) How do I fix it? 2) Will the car do anything else goofy like shut down if it THINKS it is out of gas, when it is not? 3) Is it time to finally get rid of the car I've really liked for like 10 years? 4) As long as I keep a gas log so I know when to fill up, can I keep driving it?

Thank you in advance for your good help. I do not think I am loosing gas at all, I think it is a sensor problem or something.....

Frank D.

 

Wow...thank you Patrick....I am on my 3rd 12v battery, the last two have been optima's....the current one is about 2-3 years old. I will check that asap. Others have posted about recalibrating the fuel gauge. I will check the battery. Here is a dumb question...if I go to the auto store, where they check the battery with a hand held thing....and they also check it under load....can they do that using the terminals under the front hood, or do they have to check it from the battery itself in the back.....just asking because I carry a lot of tools, etc....would be a bit of a pain to take everything out of the back to get to the battery...although I would have to if I need to change it. Bummer....I was thinking of perhaps trading it in within a month or so.....hate to throw more money into it now, but it could be worse.

Can I still drive it for the next few days without worry...? I might not be able to work on it and do this until the weekend, but still need to drive about 150 miles with it in the next two days or so.....Thanks!!

 

Actually, I bought the current battery on 12/27/16 from Amazon...so it is about 2 and 3/4 years old. Then it was $167, now it is $238.....

 

Thank you Patrick...you are always such a good help here. I do see that Amazon has a 3 year warranty on the purchase....so I will have the battery checked for possible replacement. The car starts and runs fine, except for the wonky fuel gauge....do you think it is safe to drive for a couple of days? This just started occurring. Thanks! Also, if it is not the 12v battery, would you have other opinions as to what to do?

 

I actually just got off the phone with amazon and they are sending me a new battery to be delivered Friday at no charge at all. Hopefully that will solve the issue......here in Florida, most batteries die after about 3 years due to the heat. Thanks! will keep you posted!

 

Dear NoThrowningRocks, I seem to remember some way to do a test that showed up on the screen, but I've forgotten, and could be wrong. Now that Amazon is sending me a new battery, I will just replace the battery Friday, and take the "old" one down to the local shop to test it. Most all places can do that. amazon told me not to return it or anything, so we will see if the new battery helps. I do not know if there is any test for the big battery.....I've got 183k miles on mine, so I just drive with my fingers crossed. I agree Patrick is great! I am hoping he is correct with this one....

 

Patrick, would it still be the battery if the fuel gauge in one trip of say 15 miles drops bar by bar to one last bar, then blinks? The new battery will be here tomorrow, and in Florida it is good to replace batteries every 3 years either way, but just wondering, as it never went right to blinking one bar, but creeped down to it. Thank you!

 

NTR...wow. Mine has been great, just do not know when to let it go or keep it....

 

Thank you Patrick. Since they are sending me a new battery I will also do that.

 

Thank you for that video....I remember doing this years ago, but forgot how. Thanks! I will do this. Yesterday I filled up the car, and today I drove 175 miles.....the display shows 2 bars down.....seems normal. The MFD shows about 45 mpg.....normal now here in Florida with the A/C blasting. Will keep you all posted. I very much appreciate all of your kind help. Respectfully, Frank D.

 

So...I just did the check...the MFD showed 12.3 not under load. I did then power it on, with A/C blowing, and it went UP, not down, to like 14.3. SO....is that good? Is my battery ok..? The fuel gauge seemed better today, so perhaps everything is good...(for now)..? Is 12.3 ok?

Thanks! Frank D.