celica overheated., Fan/Fan switch/Thermostat? Options

[Badkarma]

my gf's celica overheated today and by the time she realized the temp guage topped out, she was home and the car was steaming. when i got home from work i checked the coolant, it was low so i filled it and it isn't leaking. (not enough to notice) so i had her start the car and the fans didnt turn on at all while the temp guage topped out again after about 5 min.

i figure its probably the thermostat, Fan Switch/Relay, or the Fan itself. am i on the right track? how hard is it to pull the thermostat or fan switch/relay?

Thanks, Erich

[dliverance]

Yeah, my coworker thinks its the water pump too. He said it sounds like there is a problem with the impeller. just today i drove it to work just fine (2.5 miles) and on my lunch break i drove it down to the bank and it reached up to about 3/4 of the gauge. i withdrew moneys from the atm and when i started her up the temp was at normal opperating temperature.I even made it all the way back to work without the gauge going up once.Not even for the five minutes that i sat at the redlight next to my job. when i got back to work i let her cool for 15 minutes and checked the fluid level and everything was ok. down about three millimeters but nothing drastic.I'm praying that its the water pump. If so I can fix that this weekend. But i still want to pressure test the system.