99 C240 Fuel problem

[davew210]

I have a 99 C240 saloon.
When the fuel gauge gets to around half way down, I am running out of fuel. It takes around £25-£30 (@ 85.9p per litre) to refill the tank from half way. Is this the normal amount the fuel tank should cost to fill from empty? If it is it shows a fuel gauge problem. If not, any ideas? Any help would be good as the AA are getting a little fed up with helping me out!

Thanks

 

[jberks]

From memory your tank is around 60 litres - so 60 x 90p is £54 to fill up.
So if you're running out and then putting £30 in to fill it, there is something very odd going on.
The gauges senders are known to fail but that doesn't sound like your problem.
Are you saying that the gauge shows 1/2 yet you run out and then when you do fill up, you only get 1/2 tank's worth of fuel in?
If so, I believe the tank may be physically built in 2 parts and one is not working properly - poss a blocked pick up pipe. I dare say Malcolm will have a diagram!
Malcolm - over to you!

 

[Ultymate]

Here's a schematic of your tank layout http://www.detali.ru/cat/oem_mb2.as...GM=717.464&CT=F&cat=45H&SID=47&SGR=015&SGN=01 it is sort of two halves, like a dogbone shape I also notice theres a priming pump in the tank to prime the main fuel pump which is a external to the tank, maybe there's a fault with the priming pump :-? Unless the internal pump is there to move fuel from one side to the other

 

[Iain the gadget]

Make sure the tank isn't damaged. If it is compressed in anyway, this could seriously affect your capacity whilst the sender unit could be damaged in such a way that it will be recording the wrong amount of fuel.

 

[davew210]

Thanks for the replies, the two half tanks would seem to fit the problem. I have not been able to run the tank below half way as I have run out of petrol before then so maybe its only using one tank. Is there a pump that transfers fuel from one side to the other? If so, how do I get to it? Do I have to take the tank off the car?