scum in primary filter bowl

[Nigel Birch]

Anyone seen anything like this before? A sort of scummy froth floating on top of the diesel. I've been using Fuel-set for the last couple of seasons. I've changed the filter now and got rid of it but it would be nice to know why it was forming.

20180411_145607.jpg (1.57 MiB) Viewed 1200 times

[mikebuggy]

I'm surprised the engine ran at all! was the liquid in the bottom of the bowl good quality clean diesel, or was it discoloured water? It looks to me like a frothy interface between heavier dirty water below and lighter diesel above (within the cartridge). The froth could be an aerobic reaction between the additive, the fuel, water (from the fuel or from condensation)and any growths in the fuel.

[Hillary]

Yikes! that looks horrible. I would check the tank for diesel bug and also check that there isn't a poor seal in the filter thats allowing air to be drawn in causing the bubbles but if that was the case its unlikely the engine would run at all. But the cause needs finding and fixing before you run the engine again you don't want that muck drawn into the fuel pump and injectors.

H.

[Nigel Birch]

There was no water in the bowl just diesel and the froth and air above it. The engine was happy enough to run but I wasn't running it under any load.

It's all cleaned out now so will just have to see if it recoccurs I guess.