Temp gauge going funky, Updated! Changed Thermostat but still does the same prob Options

[reko]

As i was driving on the highway on friday night i noticed that my temp gauge was almost at cold which isnt normal for a sunny summer day.

After rolling for 10mins, it went to normal temp. but started to go slowly from normal to cold back and forth 4 to 5 times after what it stays at the first 1/4.

It did it only once, but then on the next day, it did it 2 times and went back to normal.

Nothing happened yesterday, but still, i dont really like this.

I'm thinking thermostat, but who knows?

Is it bad? I mean I went to school today (which is about 20kms from my house)... should I change that tonight?

**UPDATE**
25/08/08: Changed changed the thermostat... The shaft bent so it was stuck open so I just put one for Camry since the one for Celica 2.2L didnt fit (dont know why but anyway....) Still does the same problem as before... temp gauge isnt stable...

So what's next?
Water pump maybe

This post has been edited by reko: Aug 25, 2008 - 5:47 PM

[Batman722]

it's the thermostat stuck open. Cooler coolant is continuing to circulate through the system cooling the engine more than what is should be. It's a bad thing if the stat was stuck closed and there was no circulation and things get real hot real quick.

That's "OK" and doesn't NEED to be changed asap. You could wait a few weeks if need be.

[reko]

it's the thermostat stuck open. Cooler coolant is continuing to circulate through the system cooling the engine more than what is should be. It's a bad thing if the stat was stuck closed and there was no circulation and things get real hot real quick.

That's "OK" and doesn't NEED to be changed asap. You could wait a few weeks if need be.

All good.

It still doing it... temp gauge stays between first 1/4 and normal temp... depens on if I'm on the highway, in traffik or just hitting the streets.

I'll stop by to auto-part after school.

Anyone knows if i can buy the one for the Camry since its the same motor? Because usually they dont hold celica parts... but they do for Camry (I know, it's dumb!)

This post has been edited by reko: Aug 20, 2008 - 9:14 AM