When you check the color of your engine oil and notice that it has turned milky white, foamy, sludgy, or light brown, it is an indication that something might be seriously wrong. A visual inspection of the underside of your oil cap may reveal milky oil, which is usually thicker than regular engine oil. This milky appearance suggests that there is moisture or some undesirable liquid present in your oil system.

In the worst-case scenario, this could be a sign of a blown head gasket. The head gasket prevents coolant from entering the engine’s cylinders. When it fails, coolant leaks into the oil and mixes with it, resulting in the milky appearance. Other causes of milky oil include the formation of sludge in the crankcase when an engine remains idle for an extended period and the mixture of oil with humidity in a humid climate. Additionally, driving through deep water can also contribute to this issue. If you suspect water has entered your engine, it is recommended to avoid driving your vehicle.

Milky oil cannot perform its intended function effectively. If left untreated, it can negatively impact engine performance, cause corrosion, and damage various components. Therefore, it is crucial to consult a mechanic as soon as possible to determine the underlying cause and proceed with the necessary repairs. Once the cause is identified, the engine will need to be drained and flushed to remove the contaminated oil before fresh oil can be added.