What causes milky car oil?

Milky, frothy oil usually means coolant or water has mixed with your engine oil. The most common cause is a blown head gasket, which allows coolant to leak into the oil passages. A cracked cylinder head or engine block can create the same problem. Sometimes condensation builds up from frequent short trips where the engine never fully warms, giving oil a milky look under the cap. A faulty oil cooler can also let coolant seep in. This contamination reduces lubrication and can severely damage your engine if ignored. Get it checked immediately. For expert diagnosis, contact Crossroads Helpline.