I have a 2001 Ford F350 Superduty. When it is cold out side it leaks diesel from the fuel filter/water seperator. So far this only happens when it is cold outside. If I plug the truck in it does not do this. What would cause this?

Hi,
the diesel system on your vehicle works on a continous 'loop". Tank to engine....engine to tank. The fuel filters and the water separator are very susceptible to the diesel fuel 'clouding" , making the fuel heavier to push around the system. The 'clouding' is actually a type of wax which is normally held in suspension within the body of the fuel and thus is not a problem.

The wax starts to plug up the fuel system, and cause lots of problems. The fuel, being harder to push around the system, takes more pressure to move it. This will result in diesel leaqkage at any and all outlets to atmosphere at the pressure end.

The problem is usually resolved by adding an additive to the fuel tank, or having a water separator with a heater., There are also weap-around heating cables which can be fitted to fuel lines to aleviate the same problem. If your water separator has an automatic dump valve, you might like to check that it is functioning correctly and the water content is not freezing and providing an exit for the diesel fuel.

Good luck.

I have problems with the turbo which I am changing, the issue is recently the engine oil has started to increases in voluum and I have to drain out some oil could this be due to that some one putting the wrong oil in the engine using normal engin oil rather than diesel oil could that be the problem