Fuel gauge woes C250 2010.

[nuffer]

Hi. Hope some of you clever ones might have some insight to this. My car had run out of fuel. It was recovered and was diagnosed as out of fuel, the gauge showed 1/2 tank?. Off to the garage, they replaced both fuel gauge sender units. 3 weeks later out of fuel again, the gauge shows half a tank. We put (me and the green flag man) 10 litres in and it fired up?.. Does anyone have any ideas as to what could be wrong. Please no fuel jokes. Well not to many

 

[Ted]

If the fuel tank/cap isn’t venting it can start to collapse. This can push up the bottom of the tank and the floats so they read incorrectly.
Just a thought...

 

[alecmascot]

I think this is because you have a saddle-tank arrangement with a sender in each half.
When you run out of fuel one half is still full because the mechanism to transfer fuel between the two halves is not working.
The fuel gauge is reading correctly.
From other posts I have read it seems that the return flow from the HP pump may not be working properly.
Is your C250 petrol or diesel ?

I just found this thread:
MB C Class W204 Estate in tank fuel pump/sender.

 

[nuffer]

Hi. It’s a Diesel

 

[nuffer]

I think this is because you have a saddle-tank arrangement with a sender in each half.
When you run out of fuel one half is still full because the mechanism to transfer fuel between the two halves is not working.
The fuel gauge is reading correctly.
From other posts I have read it seems that the return flow from the HP pump may not be working properly.
Is your C250 petrol or diesel ?

I just found this thread:
MB C Class W204 Estate in tank fuel pump/sender.

Hi. I think what you state makes sense. Is the transfer mechanism built within the fuel pump and what would correct it. Thanks.