temp keeps going up and down on my 2000 grand prix gt whats wrong

Fan work all the time?

No didn't replace water pump and the fans are on when I check

I tried to bleed the system of air but don't know how just kinda winged it did it twice for about 10 minutes do I need to do it longer or something else I'm not doing

Did u put the thermostat in the correct direction. Does it actually over heat or just fluctuate and I are u driving it when it does, going fast, driving slow or parked. Does your passenger floor board get wet and/or does water come out of a/c drain with a/c off

thermo is in right just fluctuates does it while parked or in stop and go traffic no water have seen water coming out after have run ac but from underneath the car while off

fans seem to run all the time and put on new coolant res tank

Could have bad gauge