Whoo.. Full of gunk. Not sure if it diesel sludge loosened by the bio or bacterial growth. My guess bacterial, because it was sticky and everywhere. Couldn't quite figure out how to clean it at first. Pressure hose at car wash did virtually nothing. I called around to a lot of radiator places to see if someone would boil it, but very hesitant answers. I also started looking to buy a new/used one but couldn't find one Anybody have any ideas on this just in case?

However, after letting the tank soak for a few hours with "Purple Power" and extra lye, looks like most stuff came out. I will then take it to the car wash again and power wash out the residue and see what happens.