fuel leaking?

[B92 8NW]

I'm chasing a high fuel burn rate issue. Mechanic says fifteen to the hundred is as good as it gets for a Tdi automatic on 32s.

I disagree. The left mudflap often has liquid diesel drops on it. Is it likely the tank connections are leaking?

[nice1guv]

15s does seem a bit high!?

It might be leaking from one of the fuek tank connections, but then I would have thought you would be sucking air and getting running issues as well?

I am about to replace the (looks like 2inch) hose that joins the actual filler to the tank.
It isn't leaking yet, but the hose has lots of small cracks in it.
Might be worth taking a look at yours as well.
It's up behind the rear wheel on the drivers side.

[langy]

Actually the mech may not be far off - The factory specs for an auto Tdi aren't terribly crash hot to begin with. Throw in age of various important bits and big wheels ( minus difference in odo if you haven't swapped speedo gear drives or diffs) and 13 or 14 around town sounds fair. 10% bio diesel dosen't help either.

As usual, the tdi likes having clean air and fuel - if you spend a day cleaning the intercooler, new air/fuel filter, tighten all the intercooler hose connections, give the sedimenter a clean and the fuel tank a big dose of injector cleaner you should see some improvement.

Those drops on the mudflap could be oil if you have a weeping seal somewhere. At speed the airflow can blow weeping material all the way to the back.

[dmdigital]

Apart from the lifter pump check the hard lines around the injector pump. Remember it doesn't take much of a leak to make a diesel smear and it can run down underneath.

As for the rear, check the little drain on the fuel sedimenter trap and also the seal (from memory the D1's screws in half and there's an O-ring seal).

As for economy 15L/100km is probably right for town driving. Long highway at 80kph should give you a good idea of whether there's an fuel economy issue.