Black fuel filter(pics included)

2016 w900 12.7 Detroit. I don't see any dark fuel in my tanks from what I can see. My filters ave been looking like this for about 2 months.(each time I change them). Only issue I know on the truck is the exhaust manifold....I can see exhaust(very little)..it appears it coming from where the manifold gasket may be broken. I don't think the manifold is leaking though.

I changed my oil on 6-1 and I noticed my oil was pretty dark. But when the tech went to show me that he filled the dipstick the oil which is usually brown was very dark still. I questioned whether he put used oil in there it was so dark lol.

I got an engine tune back in the middle of April was the only change ive done. I don't notice any performance issues. More black smoke of course and since the tune ive never gotten good fuel mileage anyways since I pull heavy haul.

 

I changed that filter this afternoon and forgot to cut it like you mentioned. So I just went out and cut it and its not slimy....(its been sitting in my to car for a few hours if that makes any difference)

 

Yes ive poured some diesel keen in there this morning. I purchased some biocide and it'll be here wednesday I think. None of local places had any.....

 

12.7 has virtually no place for oil to transfer into fuel.

 

I don't exactly know the order of how things flow but, my fuel tanks seem to be fine. The fuel is the same color as far as I can see. I have an anti theft fuel thingy(lol) that makes it hard to look down in there

 

When you say "combustion gases getting by" is that another way of sayin my injector is leaking? That was my thought. As I thought that or the algae......