The oil in the fuel

[AlexGramm]

My "Freddie" (Freightliner Century) asked a question. Why is oil in the fuel. After 3,000 miles of road, I pour 4 liters of oil. Engine DD.


I think the problem is that the oil is in the fuel return system. But as the oil gets there?

There is a second version of the cause. This quality is oil. My boss likes to save, and now I dont have money to buy good oil.

 

[AlexGramm]

I found the cause of the problem. This ring for sealing the fuel burner. The solution is 3 dollars (the price of rings to seal).