You might want to run a bottle of Redline Diesel Fuel Catalyst or 85+ through the fuel system if you haven't already. Use 1 whole bottle for the first tank of fuel, and 1/3 per tank until time for your next oil change. See if it doesn't help clean up the amount of crud. It may take driving the car a little harder, and a couple of oil changes, but I wouldn't be surprised if it cleaned up your engine...
"We drive into the future using only our rearview mirror."
- Marshall McLuhan -
Northern California Wine Country...
"Turbos whistle, grapes wine..."