Is It Easy To Dip A Fuel Tank?

[renegadefm]

Asking a question for my neighbour. 

Basically my neighbour has a Citroen C3 diesel just like this:

https://images.app.goo.gl/zghU1sWBp3X3AR4J9

 

She went to a fuel station to fill it up, but it wouldn't except the fuel, just as if there is a blockage or the tank is already full. 

So she took it back to the garage she bought it from, and they have said the tank is full which is why it won't except any more fuel.  But the gauge is saying the tank is empty and a warning light is flashing to suggest the tank is empty. 

 

So how easy is it to dip the tank to clarify if there really is fuel in there, or is the gauge at fault? 

[douglas9401]

If it can get from home to petrol station to dealer then back home again it suggests there is fuel available.

Why would you disbelieve the dealer who said the tank was full?

[Old_Geezer]

Sounds like a problem with the sensor.

Get it looked at ?

[renegadefm]

douglas9401, 

Well obviously there's a question mark, because the gauge is saying the tank is empty, and warning lights were suggesting this. 

[Buenchico]

I agree with the dealer that the tank is almost certainly full.  What the dealer seems to have forgotten to mention though is that there's clearly a problem with the sensor.

Scroll down to 'Fuel gauge reading empty when the tank is full', here:
https://www.delphiautoparts.com/resource-center/article/what9;s-wrong-with-my-fuel-gauge-diagnosing-a-bad-fuel-sending-unit

[gingejbee]

I'm thinking that if it won't take any diesel because it's already full...then the nozzle must be dipping into the stuff, because that's how the cut-off works.

[davebro3]

Fuel filler pipes these days are made so that you can't stick a pipe down & syphon fuel out. I'm not quite sure how but it probably means using a dipstick won't give a proper reading,

[Buenchico]

Grrrr!

Let's try that again!
https://tinyurl.com/ybdz24dc

[renegadefm]

At the moment I can't decide if its a faulty fuel gauge, or if the tank is full or empty. 

[davebro3]

Put a spare can of fuel in the boot, drive until the fuel runs out & see how far you get...

[renegadefm]

davebro3, 

Thats a good idea, thank you 👍

[Hymie]

I would advise against deliberately running out of fuel – it might happen when you are in the right-hand land of a motorway (giving little time to reach the hard-shoulder), or on a smart motorway (unable to reach a safe refuge), or whilst crossing on-coming traffic (stopping in their path).

 

Running the fuel tank low runs the risk of crud at the bottom of the tank being sent through the fuel lines (possibly blocking a filter, or injectors).

 

To confirm that the tank is full due to the pump is clicking-off, gently squeeze the pump trigger (which will deliver the fuel slowly) with the fill nozzle just within the vehicle fill intake, and observing that the tank is filled to the brim.

 

Don’t use this technique often, as overfilling will damage/degrade the vehicle’s EVAP system.

[ToraToraTora]

get a can of fuel and pour it in, if the tank is full it will overflow then you'll know. Sounds like the fuel guage sender is not working to me.