[TDILow3]

I ask, as Bentley has not published the 2011 Jetta manual. Does the 2011 TDI have a "water separator"? If there is a water separator in the fuel system, where is it located?

My 2003 Jetta TDI had a water drain port on the bottom of fuel filter, where as my 2011 JSW TDI fuel filter only has perimter bolts that secure the lid and no additional ports/fittings.

 

[chittychittybangbang]

Take a look at the fuel filter change FAQ article. If you have the screw you have a water separator. If you don't, you don't which sounds like your case.

Also, as you have found with your 2003, you'll probably never find any water.

 

[TDILow3]

So how does VW magically make the suspended and entrained water present in diesel fuel go away? Shipboard, water is decanted/stripped from fuel tanks as a routine matter, and finding water, even in service tanks (already spun out by a centrifuge), is a common occurrence.

Without the ability to capture and drain off the water at the filter, the updated design has to include some method of continuously ingesting small amounts of water into the engine at a controlled rate. Or pre-heating the fuel to decrease the 'free water' and increase the absorption abilities of the fuel...which would then get pumped into the combustion chambers and burned off. This can be done with a simple oil-to-oil heat exchanger loop that routes the outbound fuel past the inbound fuel separated by a common medium.

Regardless, the design has to account for it somewhere, capture and drain the water, or consume and prevent accumulation of the water.