Slow Fuel Gauge

So after 8 years of this mystery, I’ve finally figured it out.

I’ve always had a habit of never letting my gas tank go below a 1/2 tank. So I tend to fill up between 3/4 and 1/2 tank. Over the years, I’ve notice that sometimes when I fill up my tank, the fuel gauge is very slow in reading full, while at other times it show full right away when I start the truck.

I’ve finally noticed that whenever I fill up the tank anytime below 3/4 tank, the fuel gauge registers full right away, but if I fill up anything above 3/4 tank, it is slow to register full. Normally takes about 5 miles to finally register full.

It’s been like this for 8 years now ever since I bought the truck new and it always confused me. I’ve always been afraid something was wrong, but since it’s been 8 years and I haven’t had a problem with the truck, I guess this is just a characteristic of the gauge. Just thought I’d share. Don’t know if this occurs for everyone, but it always occurs for my truck now that I know what condition causes this.

 

Mine doesn’t do that, but it will stay above full for 50+ miles. It also drops slowly through the first quarter tank, then it’s almost as if you can see it dropping after that. It’s not proportional at all, but I’ve got it figured out.

 

Mine just shows whatever I put in right away. Half, 3/4, or full. Might be something goofy with the float or sending unit. Clearly it isnt hurting anything though.

 

Wow I just noticed that today when I filled up from 7/8ths tank to full (4 gallons). Not sure if it’s a bad fuel sending unit or just the cars character?

 

Happened with my old 2nd gen too!

 

I would like to wean mine off of fuel altogether...so far no luck...
The float runs a rheostat basically. If it fails to float 100% "high and dry" or pivot freely then you will see slow response. In the case where tank remains "full" for while longer than you think it probably, should, the range limits for the gauge are just hit... No biggie either way once you know they are there--just play accordingly.
Getting used to this situation (not pronounced "problem" at all) will save you lots of money.

Now, if it registered 1/2 and you go empty, then that is a potential problem.

 

Piss on it until the light comes on

 

Put a few Adderall tabs in the take to wake it up

 

its slow for you to get it up the last part because of the dampener in the cluster assy and the very little voltage difference

empty tank makes it break past that dampener stickiness and gets it up quicker

 

Basically, it happened to me the first time after I filled it up from sitting for a long time. It had been like 2-3 months since it had been driven, and no idea when the last fill up was.
The gauge went down just fine, but coming back up it took like 20 mins to show a full tank.
The next tank was fine though

probably just a tiny bit of corrosion or friction

 

I know this is an old thread, but this came about from searching.
Same thing happened to me today. I thought something was wrong with my float or my gauge...or maybe the pump clicked off too early. I was topping my truck off for what's planned to be a lot of driving from Friday to Sunday. I was about 5 gallons down from full, so I filled up and gauge needle didn't instantly pop back up as usual. 5 miles later and the needle slowly crept back up to full.

Based off of your post, it seems normal (unless you found something after this thread) and just something to keep in mind if filling the tank from 3/4 or more to full.

 

Nope, this is exactly what happens. It’s like clockwork, happens every single time under those conditions

 

My Ford did strange crap like that until I got the fuel pump replaced. My drive way is about a 30 degree downhill slope. On a full tank, with the front end pointed down the driveway you could start it up in the winter time to warm it up and the longer it sat there the needle just kept dropping until it pointed to empty. Pull it out of the drive way and start driving it down the road and the needle would slowly creep back up to full.

 

People with this type of problem have seen improvement, in some vehicles, by using Marvel Mystery Oil in the gas at the rate of 4 oz. to a tank of gas. If it is a sticky or corroded sensor it can help and won't hurt anything. It may take a tank or two to see effects. We had a '15 Forester that would not read full after filling up with the ignition key on (listening to radio for instance). It was some factory glitch that the dealer new about. Key off, it would fill and read fine.

 

I realize this is an old thread, but this just happend to my 09, tank had a little above 3/4 tank full and filled up. Took about 5 miles to get to full mark, this was the 1st time it happened to me. Was the issue found, or has anyone else had this issue happen before?

 

my 2013 does this occasionally, maybe a couple times a year. never really paid much attention. next time i will.