98 Corolla 1.8...fan problem

[perro]

Fan doesn't engage...I have replaced the heat sensor and the coolant sensor. The relays are good, and the fan motor actually works, but it just won't come on like it is supposed to so the car overheats. The thermostat is open and water is circulating, too, but the fan still won't come one. What else could be the problem? Any ideas?

[REN69]

Sounds like the thermostat is shut, the fan won't come on if the thermostat is not letting the coolant through to pick up the temp reading and turn the fan on.

change the thermostat and go from there.

[perro]

Oh, sorry, I should have mentioned that the thermostat IS open and the coolant is circulating (I edited my question to add this). It's weird, I can't figure it out. I tested the fan, the relays, and put in the new sensors, but still the fan won't come on.

[REN69]

Then it's the rad, probably plugged somewhere along the lines and it's not cooling properly OR the fins no longer cool the liquid, push the fins and see if they're brittle and fall off easily, if so then you need a new rad.

[perro]

If that's the case (bad radiator) wouldn't that STILL make the fan kick on (since I know the fan works- I have tested the fan and it runs)?

[REN69]

When my rad died, the fan never came on.

[perro]

Thanks!