We bought a 9350 Case IH tractor with M11 cummins engine with 1230 hours. We have owned it a few months and have had engine problems. Number one cylinder injector has failed three times, and just went again. I pulled off a fuel line and noticed engine oil in the diesel fuel. I checked the exhaust temp for each cylinder and number one runs a lot cooler than the rest. Coolant is clean, and oil level is good. Any ideas as to why I am getting oil I the diesel fuel. and why that first injector keeps failing??? Thanks Joel