Does anyone's fuel guage give eratic readings? Mine will "for example" be just above a 1/4 tank when I start the car and stay as long as the car is sitting but as I drive it will after a while start to go up to almost 1/2 tank and then stay there when I shut the car off and still be there after I start it to warm it up. However as I drive it will then start to go down again and then start to go back up again. It is very slow and not due to turning or anything like that.

 

Fuel level senders is probably the cause.

 

Our 2008 S-Type has been doing the same thing. Now the fuel gauge has moved past full, to it's max off the scale reading.
I plan to search the internet and download the diagnostic in the Jaguar Service Bulletin JTB00014.
Hopefully that will shed more light on the problem.

 

SNG Barrett carries fuel sender and the locking worm clamp. Pretty simple replacement. Post face-lift, remove rear seat cushion, sender is located drivers side.

 

Thanks.

 

You may not want to go to the trouble outlined in the service bulletin below and just replace the sender.. It looks like this procedure was to determine if it was for a warranty claim. But it might be of interest to you.

Erratic Fuel Gauge Reading Fuel Tank Sender S-TYPE R Repair Procedure
http://jagrepair.com/images/TSB/TSB2...%20Reading.pdf