An interesting, albeit expensive find. That inline filter , if there aren't any types of flow restrictors would seem like n easy place to swap in something with a water seperator.
How about an ALH filter in that space.
I'll keep the Powerservice white bottle going for now.
YES, keep the PS going and with every tank. PowerService Diesel Fuel Supplement (white bottle) is the one to use. PowerService Diesel Kleen (silver bottle) doesn't do anything for water. The white bottle stuff would be better for year round use. Also as I mentioned earlier fuel up ONLY at busy, high volume, high diesel turnover stations along major routes that get lots of diesel truck traffic. Go where the big rigs go to fuel up to get only the freshest fuel in the region and to avoid getting fuel contaminated with water from condensation. The PS will add lubricity and take care of what little water you can't avoid getting.
Maybe someone can recommend a separator kit that can be added inline?
I was sort of thinking the same thing with an ALH filter. I had envisioned leaving the stock filter alone and install an ALH filter in line with the stock filter and rely on the ALH filter as a water separator. There may be aftermarket water separators that would work too. Water is the big enemy of diesel fuel and more so than lack of lubricity is. The water separator is ultimately the engine's last line of defense against water ingestion.
Years ago with MK4 TDIs and the ALH filter, a number of TDIclubbers reported never finding any water in the separator during a FF change. This has led some TDI owners to believe that the water separator doesn't do anything. I think it's really just saying these owners are getting good fuel because I found a case where the water separator in an ALH filter definitely does work. Several years ago I helped a co-worker do a FF change in his 2000 Jetta TDI and he asked me how often it should be changed because he had never changed it or knew anything about it. Uh-Oh, I thought. This was at 205k miles.
He bought the car used with around 40k miles on it and never touched the filter and never gave it any thought. He kept up with other maintenance including the timing belt but never touched the fuel filter and it was still the factory original filter. When we emptied the old filter, about 1/3rd of the contents was rust-colored water.
The water separator was essentially swamped with water and the filter canister was rusting out on the inside.
The filter was also rusting on the outside too. It was rusted in place and we had to work to break it loose to change it. I would think if the water separator didn't work, the IP would have surely died an early death, yet the engine was still running perfectly fine and with the water separator swamped with rust colored water.
I educated him about the importance of changing the FF on schedule. I think I helped him dodge a bullet that day. That TDI is still on the road today at only 400k miles and still running on its original IP.
From what I've seen, I can say the water separator in an ALH fuel filter definitely DOES work.