Caution: Diluted oil can cause severe engine damage.
Check the condition of the lubricating oil.
โข Thin, black lubricating oil is an indication of fuel in the oil.
โข Milky discoloration is an indication of coolant in the lubricating oil.
Coolant in the oil can be caused by:
โข Expansion plugs leaking.
โข Lubricating oil cooler element leaking.
โข Damaged cylinder head or gasket.
โข Cracked engine block.
โข Casting porosity