Aargh fuel problem

[brad]

Seeing fuel is always drawn from the bottom of the tank, why is a low level problematic?

Just guessing - because the algae is floating on top?

[gldgti]

algae will hang around closer to the top of the liquid volume for sure.

Also, any solids that settle out of the liquid will become more highly concentrated as the volume of fuel in the tank is decreased.... its hard to explain in text, but basically when there is lots of fuel in the tank, the probability from moment to moment of the pickup pulling in some solids that are washing around in the bottom is lower than when there is hardly any volume of liquid in the tank, but the amount of solids is pretty much the same.

I guess another way to put it, is that when the tanks is full, the amount of fuel being taken out by the fuel pickup is relatively small, compared to the available volume of liquid.

When the avialable volume is very small (tank nearly empty), all the solids are washing around in the remaining fuel, so the concentation is very high, and you are therefore more likely to pull it into the pickup.

Trust me

If you've ever tried gold panning, that might help.... maybe

[Ryeman]

That would be the case I guess if you weren't in the habit of letting it get low.

[gldgti]

Mostly, if you fill up once you get just into the red (in a VAG car anyway) you usually have at least 7 litres in the tank remaining. I know in the Skoda (which I never ran out of fuel) I could do more than 120km in the red. Same in the cabriolet.

[sparkie]

So tank cleaned, actually an easier job than I thought, fuel filtered and put back in, new filter, hard to prime (again), but all good now! There seems to be some agreement out there that the combo of bio and petro diesel can be a problem, plus having the fuel tank low (lots of air).

[bluey]

What about a regular algicide-containing additive?

[sparkie]

That's what I am doing now, new mechanic suggested using it monthly, local car parts place says the instructions on the bottle say every tank! I am sticking with the former!

[Skooter]

That's what I am doing now, new mechanic suggested using it monthly, local car parts place says the instructions on the bottle say every tank! I am sticking with the former!

Discussion on additives on another thread here too. Goes without saying that the instructions are to use in every tank! Sound financial reasoning from the marketing dep't.