While idling outside of my house after driving home, I started to see some smoke from the hood of the car. I looked at the temperature gauge and saw that it had risen to the hot side. I turned off the car and went to check outside; I saw some liquid dripping slowly, which was blue color. I made an appointment with Nissan. I came to learn that the engine coolant fan had malfunctioned, causing the vehicle to overheat while idling. I was unable to pay for the part and labor at the time, as it was costly. It is available for inspection upon request. My safety was put at risk because of the overheating engine; while it occurred initially during idling, it also has occurred while I was driving. This issue could cause loss of power, making it difficult to maintain speed and potentially hazardous in traffic. The problem was confirmed at the dealership, though I was initially told there was no issue. When I insisted that there had to be an issue, they re-assessed the vehicle and expressed that there was a code signifying that the engine coolant fan had malfunctioned previously. No warning lamps, messages or other symptoms of the problem were present prior to failure. Only after repeatedly insisting that there was a problem, did the inspector at the dealership double check for codes. This issue seems to be evasive, as it does not present an issue consistently.