I have a 2000 maxima, the other day experienced overheating issues while driving. Put in new coolant (since I barely had any left I figured replacing it would do the trick). Drove it today (2 days later) and drove around for about 10-15 minutes. It began to overheat while driving in a parking lot. I thought it could just be because of how hot it is outside since it is about 90 degrees F, but I still want to try to fix this problem quickly and as cheap as possible since I am a college student with barely any money. Any suggestions?