Here is a 2000 Dodge Ram 2500 Truck with a 5.9 Liter Cummins Turbo Diesel Engine that we had in the shop a while back for overheating problems. Pressure testing the cooling system initially showed what appeared to be a severely blown head gasket however closer inspection upon disassembly revealed a rusted through “freeze plug” or casting core plug in the top of the cylinder head. This allowed the engine oil and engine coolant to mix with the loss of coolant winding up in the oil pan. Once back together and after extensive decontamination of the engine oiling and cooling systems this diesel engine with fairly massive crankshaft bearings seems to have survived the ordeal with the exception of the turbocharger that spins at 75,000 rpm coming apart from lubrication failure. The bottom line here is don’t let cooling system neglect cause a 2 dollar part to rust through leaving you with a major repair and collateral damage.