Why is diesel in your radiator 60 series Detroit?

Answer 1

* Failing head gaskets * Warped heads * Cracked engine blocks and heads * Coolant leaks to the outside of the engine through a breach between the head and block * Coolant leaks through the headbolts * Intake manifold coolant leaks * Overheating due to a cracked head or block * Oil leaks into the cooling system (Radiator) * Coolant leaks into the oil * Excessive steam and water from the tailpipe i know the 60 series pretty good and the first thing i would check is the oil cooler, if that checks out i would check the liner o-rings by pulling the oil pan off and pressure testing the coolant system

Answer 2

You probably need to replace your injector cups.