Milky stuff under oil cap but oil on dipstick looks normal

Deep breath — this is almost certainly **condensation**, not a head gasket. Here's what happens: Short trips (under 15-20 minutes) don't get the engine hot enough to burn off moisture that accumulates in the crankcase. That moisture condenses on the underside of the oil cap (the coolest part of the engine) and mixes with oil vapors to form that milky/mayo looking stuff. **If it were a head gasket:** - The oil on the dipstick would also be milky - Coolant level would be dropping - You'd see white sweet-smelling exhaust - The oil would look like chocolate milk, not just under the cap **The fix:** Take the car on a 30+ minute highway drive. Get it fully up to temp. The heat will burn off the moisture. Then check the cap again — it should be clear. This is extremely common in winter, in humid climates, and for cars that only make short trips. Nothing to worry about unless the dipstick oil also turns milky.

This happens on my Rogue every winter. I live in the Pacific Northwest — lots of moisture. One good highway drive and it clears right up. Been doing it for years with no issues. If you want peace of mind, you can get a combustion leak test kit from any parts store ($30). It tests the coolant for combustion gases and will definitively tell you if the head gasket is leaking. Blue fluid turns yellow = problem. Stays blue = you're fine.