996 C4 fuel gauge problem

[racin jason]

I've just put £40 worth of fuel into my 2001 996 C4 cab and the fuel gauge hasn't even moved to half full and the mileometer that tells me how many miles I've got to go before empty, reads --- miles.

Anyone had the same problem please and any idea's how to sort?

Many thanks
Jason.

[sportsandclassic]

Hi, try filling the tank. Needs to see a certain amount of fuel through it to work out the fuel gauge reading. The 4wd cars have a saddle type of fuel tank unlike a 2wd.
Worth a go before anything else.

Mike

[racin jason]

Hi Mike,

Will fill her up to see if that makes a difference. Will post as soon as done.

Thanks for the tip.

Jason.

[skibum]

Yep - my C4S went down to 18 miles on the trip computer, put in £40 and didnt register a drop. Took it to petrol station next day, topped it up with another £40 odd and it was brimmed.

I think it only happens when it goes really low, but could be wrong.

Bit annoying as I dont use mine much and dont want to brim it every time (fuel degradation, etc.. )but hey ho...

[BliarOut]

Yup, it's due to the saddlebag design of the tank on the C4, you need to fuel up sufficiently for it to register. Bit of an oversight that one...

[cd1957]

Hi make sure you lock the car, then the dash can reboot to new level, floats can stick on pipework in tank.

Chris

[shortlad]

sportsandclassic said:

Hi, try filling the tank. Needs to see a certain amount of fuel through it to work out the fuel gauge reading. The 4wd cars have a saddle type of fuel tank unlike a 2wd.
Worth a go before anything else.

Mike

This was defo the case when I experienced the same thing in my 996tt. Fill it up and it should sort itself out.

[CammyG60]

I've had exactly the same problem, I let it run down to the red and put £20 of fuel in. Gauge read nothing.

Next morning I put another £20 in......still no movement on the gauge. Filled it to the brim and bingo, gauge working perfectly fine again.

[996TT02]

Yes, the in-tank gauge only registers from half full upwards (nominally, for purposes of understanding). Below the half way point, it is the OBC that actually calculates the amount of fuel left in the tank, because it knows how much has been dispensed via the injectors. It can not know that you have filled the tank if you don't fill sufficiently that the in-tank gauge is again activated, so will report that you are low on fuel to the dash gauge.