after filling up, the fuel gauge remains on full. been driving for about 100 mi. and still no movement, 

any ideas?

Mine now exhibits this behaviour, it suddenly changed from coming down fairly quickly when tank full to indicating full for 100+ miles.

 

I think I probably used to overfill it too much (not stop at first click) and probably did something to the measurement float mechanism.

 

It still works but highly optimistic for first 100 miles or so. Then drops quickly.

 

 

Thanks will keep an eye on it,

i read that it is possible to fill a expansion tank and that also creates problems but not sure.

Welcome.

Called venting and be careful not to do that.

Does your filler have the little slide in the filler pipe opening that is used when venting?

It lets 7 litres more be filled.  If you do that and then park up like at the cold temp you have today then the car sits in the sun that is too risky.

 

 

Edited 26 October, 20187 yr by Offski

it has the same sort of nimble that moves up and down, i have moved it about but gauge does not move 

The gauge might drop when a bit more fuel is used if it was vented in error.

 

The little slide in the tank just lets air out and fuel in, sometime 2 or 3 pushes and extra fuel in.

I use it when at 'South Road Tesco' with my 10 pence a litre off voucher to get as much petrol in before heading off to get more range.

I never do it if only going to go less than around 60 miles....

so should i wait to refuel?

Do not fill beyond the first click. If you fill the expansion space among other problems you may cause,  you will probably be pouring neat fuel into the evap system, evaporation canister, part of the vapour control system, and damage it. Costly to fix.

 

The shift in fuel level indication is probably not fixable without removing and physically resetting/recalibrating the fuel level sensor, which is in the fuel tank. Just live with it, like me, its a minor issue.

If you filled up and normally you get 450 miles or more from a tank i would be sure to fill up again before you have done 400 miles.

But if in another few miles the gauge has not moved and you want it fixed best not fill up until you get that done.

thanks guys for the help and advice.  

I too, would suggest that it will drop suddenly after  a while. You may have just filled so high, it won't register it for a while.

Many fuel indicators are like that. They tend to say lots for ages, then drop suddenly, often say low when you know you have more. They are t best, a guide so don't really rely too much on them if you live a long way from a fuel depot!

Also, perhaps unplug the battery for a few mins and re-connect. This may give you a better reading afterwards.

The fuel gauge on my 2014 Citigo Sport  now shows more fuel that is actually in the tank. And the Infotainment Range figure is based on the fuel gauge reading. As is the built in Range figure that comes up in the speedometer window. I can manage it on the basis of known MPG vs actual miles since fill up, but is there a quick fix, does anyone know?  Otherwise I guess it is going to be a petrol tank out job, and that will be costly.

 

HELP!

Try the ol' battery off, wait ten or so mins, then back on ploy. You will be surprised the amount of issues this will "Cure".

By coincidence I had to replace the fuel pump (came with gauge and float) in my son's Fabia at weekend. The level indication is such a basic thing - the float moves a contact on the arc of potentiometer track - that I can't imagine any issue with the float unless it's fallen off the coat hanger like wire it's attached to completely. The wires to the sender which pick up the resistance signal are pretty fine, so another possibility is that one of these wires has become detached. I can't imagine a problem at the connector to the pump/sender as it's locked on and couldn't come loose without cutting power to pump altogether!  Another possibility is fault at the other end i.e. the electronics driving the fuel gauge segment reading.

 

If it becomes a real problem then you could investigate at the pump, but if you decide to do that then run the fuel as low as possible. I had to change the pump with a full tank so had to be careful not to spill/drip fuel around the seat, and it feels more hazardous when the fuel is lapping around the opening! You wouldn't need to pull the pump all the way out just to check wiring to sender, but you would want it safely away from car and on workbench if you wanted to check resistance readings (Haynes manual says what range is for registering empty to full). There's a reason why so much safety thinking goes into fuel tank and venting design, so don't pull the pump unless absolutely necessary.

it seems to have unblocked itself as the fuel contents dropped, but will be keeping an eye on it