Fuel in oil

[carlos18]

I have a 2007 Cummins isx I'm working on truck it has fuel in the oil. I removed the cover and put dye in the fuel. It's leaking from injector 3 (infront of fan clutch) and I even replace it with a new injector with new oil rigs. I put the purple light and it still has diesel coming out of injector 3. I changed the injector sleeve and it's still leaking fuel. I looked at the head and there's no cracks that I see or when I removed the sleeve. I need help. I'm not sure why fuel is in the oil and it's only showing on injector 3. I provided a picture with the dye marking in injector 3