overheating saturn

fan only runs when temp sensor reads overtemp. does car overheat while moving or just when stopped for a while?

It doesnt overheat if im on the freeway but in stop and go driving it does.

when you say overheat, do you mean gauge reads to hot or there are other symptoms like noises under hood, steam under hood, smells,etc. you can buy a small palm size push button temp reader at the harbor freight store for about 10$ and use it to read engine temp by pointing at different parts of engine and coolant hoses. you can also pull relay and short together the 2 heavy contacts in socket to see if fan runs. you could run your own switch and turn it on that way. google says this is a COMMON problem with these cars and no magic solution has been found! the computer has it's own temp sensor and tells fan to turn on by firing relay.the guage has it's own sensor too. also the parts you replaced could go bad again suddenly? been known to happen more so these days. never buy the cheapest version of your parts.