Why do I have oil in a spin on fuel filter on a 1999 Cummins m11 semi truck engine? How do I fix it?

1999 cummins m11 set at 410 hp with 766k milesWhy do I have oil in a spin on fuel filter on a 1999 Cummins m11 semi truck engine? How do I fix it?
Are you sure you have the fuel filter?if so the only possible place is the lift pump seal is leaking or missing.Why do I have oil in a spin on fuel filter on a 1999 Cummins m11 semi truck engine? How do I fix it?
Trust me you DONT !!! Your looking at the wrong filter
You sure that's the fuel filter and not a bypass oil filter?


Just checking.
?, change the 'fuel' filter and see if it clogs with oil again. If it does, flush the fuel tank.
i would have to guess that the spin on fuel filter that you are talking about is actually the water filter . so with almost 800K on that motor you better take it to cummins it sounds to me that your water tubing on the upper part of the motor with bad seals. or it just wasn't put on tight . i would say time for an in frame. if your blowing white smoke after take off you have water going in to your turbo. call cummins powerstoke and tell them you need the SHOP MANUAL for the M11 make sure its just a m11. good luck driver.( P.S. you can't fix it without that manual..if you even can driver)