Why would engine oil turn milky brown in color?
The most common cause of milky-brown engine oil is coolant contamination. This can result from leaking intake gaskets, blown or leaking cylinder head gaskets, a cracked cylinder head or even a bad radiator or engine oil cooler. The situation is very serious as even a very small amount of coolant destroys the ability of engine oil to protect the engine. Very quick diagnosis and repair are mandatory to prevent engine damage.
