Q: Car overheating for some reason.

Hi there, there are several reasons as to why a car can overheat in traffic. Some of the things you mentioned are important context clues that may help rule some things out. The white smoke you mentioned NOT seeing is actually vapor. Vapor is caused by water entering the combustion area of your engine, and that would be bad news. So it’s a good thing you don’t see this or any other leaks. Honda Civics have electrical fans that help cool it down. One fan is for the radiator and the other is an auxiliary fan to help cool things down when you turn your A/C on. If one of those fans fails, the car will sometimes run normal as long as you are moving because there is air flow from driving. But, if you are in traffic, moving slow, with hot exhaust from the other cars, the one fan is not enough to cool the car down and it will begin to overheat. Once the car gets a bit hot, the coolant is pushed in to the overflow bottle. Once the bottle is full it simply overflows. That may be why you are low on coolant from time to time. A technician should be able to help you inspect the electric fans for proper operation and determine if one needs to be replaced.