Could be just plain old dirt. I wouldn't over analyze it. Clearly your old filter captured it and prevented it from entering the IP, so it was doing its job.

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'98 E300 turbodiesel

I was thinking that I was initially over analyzing also, but for some reason to me it seems that it doesn't have as much pep to it as before, but then again I haven't driven it regularly for a while, and I still had a pesky air leak somewhere in the fuel lines.

After the filter changes I did take it out for a spin and ran up up to redline through 4 of the 5 gears and it seemed to run ok.

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#dieselFLEET
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'97 E300
'99 E300

http://westcoastpetroleum.com/how.htm

HUM BUGS (Hydrocarbon Utilizing Micro-Organisms) - These organisms are found everywhere in the environment. They enter the fuel tank by air and water. They form a layer of scum at the free water-fuel interface, die, and settle on the tank bottom forming a gritty layer that appears like sand or black pepper. The combination of scum, bottom grit, and bad fuel is the major ingredient of BUG MUCK which enters the fuel system causing plugged fuel lines, filters, and gauges; corroded pumps and injectors; swollen and blistered hoses, washers, and connectors; increased fuel costs; increased maintenance costs; and unacceptable air pollution levels.

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1999 E300DT (131,800) 154,000 Black on Black SOLD

2006 CLK 500 coupe Capri Blue on Grey (zoom,zoom)
47,000mi

04 VW TDI Passat 80,000mi
(Techno)

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