The symptoms of water in motor oil include presence of bubbles, residue and thick oil on the dipstick, and emission of smoke from the vehicle's tailpipe. In addition, the dipstick has a sweet odor, the level of coolant decreases continuously, and the coolant and oil mix to form a milky fluid.
When condensation forms as the vehicle's engine cools mixes with the engine oil, it results in the presence of bubbles on the oil dipstick. It also causes a brown residue to accumulate just over the oil level on the stick, and the oil becomes thick, brown and milky.
If the block or head of the engine or a gasket is damaged, it causes the coolant, which is a mixture of water and antifreeze, to enter the engine oil. This is indicated by the presence of red, green or orange rivers in the brown-colored oil. The dipstick issues an extremely sweet odor, rather than the musky, earthy odors of engine oil. In addition, the tailpipe emits white smoke that smells sweet, indicating that the coolant present in the oil is burning.
If the coolant needs replacement each time the oil is changed, and there are no indications of coolant leakage via the exhaust pipe or on the surface, it implies that the coolant is entering the crankcase and contaminating the oil.
When the vehicle's engine is turned on, the coolant and oil blend together to form a fluid that is thick and appears like milk chocolate. This fluid accumulates on the passageways of the engine and damages it over time.