I recently started parking in a carport and noticed that when I pull into the spot, the engine fan cycles on loudly, cycles back down, then rapidly cycles back on (at least I assume it’s the fan, that’s what it sounds like). Once I noticed this, I listened and found it does the same thing at stop lights. The temperature doesn’t appear to be higher than normal and I hear the sound whether I am idling in Park or Drive.
It’s normal. When the coolant temp sensor for the fan see’s a certain temperature, it turns the fan on. This can happen after the vehicle is parked. Because when the engine stops running, the water pump stops running. So the coolant stalls when it’s hot. And if it happens to be hot at the coolant temp sensor when the engine is shut down, the fan will run.
And when you hear the fan at stop lights, it just means no air is passing through the radiator to remove the heat, so the fan turns on.