Is my fuel guage faulty?

[GT-Steve]

When I switched off my ignition on Monday night, I apparently had 85 miles remaining in the tank, and the fuel warning light was on, on the dash.

Next morning I switched the car on and it had dropped to 15 miles remaining...

So I pootled about and it dropped to 10 miles remaining.

I pulled straight into the petrol station, and put £20 of diesel in... The needle only went up to the top of the red (should really have gone over this) and the fuel warning light is still on and beeping at me that there's only 35 miles worth in the tank,

I've just today driven 27 miles and the needle is still in the red, and has been stuck on 30miles remaining, for the entire drive.



What's going on? Common fault? is there a fix?

Thanks for any help.

 

[Cockney Boy]

Fill the tank completley and monitor the drop. most cars will slowly drop to start with, but when the tank gets low the needle will drop faster as the sender/float wont be that accurate.

It could be a faulty sender, or if you have a habit of only filling up the tank with £20.00 and always running it dry then you could have damaged the sender

 

[GT-Steve]

Well today I threw another 40 litres in the tank and it shot round to over 3/4 full on the needle and 400 miles on the range.

Looks to be fixed then, at the moment... Phew.

 

[marsmail]

The "miles remaiing" is a calculation based on the present miles per gallon being recorded (possibly smoothed over a period of time). If you start the car without moving, the calculation is obviously based on fuel consumption versus nil milage and that results in a very low miles per gallon! Once you start moving the miles travelled come into play in the calculation and the miles per gallon figure will get larger, and hence the remaining fuel will "go" further.
It is possible, if you switch to that display, to see the remaining mileage/fuel actually go up! although of course, the car is not creating fuel, merely believing that what is left will take it further.
The gauge is only an indication and it is probably not a good idea to constantly run with a nearly empty tank, too much risk of stirring up muck and getting something blocked, which would be expensive!!

 

[GT-Steve]

I kinda guessed that miles remaining was more of a calculation, but generally it should run vaguely alongside the fuel guage needle too, shouldn't it???


Anywhoo, 5 days on and it's still all working perfectly. And I shall not be running the tank anywhere close to empty again if I can help it...

 

[reggieroo]

You think you have problems, my fuel tank either read full or empty even though its full......