My cooling issue revisted...

[raroZ28]

I posted a while back about my car NOT warming up. It would be about 20 degrees out, I'd drive 20 miles home from work and the car would not move up much past 160. I assumed the thermostat was stuck open. Well, now it's been the opposite the past few days. The car warms up and keeps climbing. Today the check gauges light came on and I had to pull over.

Is it common for a bad thermostat to stay stuck open, then somehow close and stay closed?

When it was staying cool, the fans weren't running constantly or anything.

I noticed today when I popped the hood, I could hear a fan, and feel air, but the two fans that you can see behind the radiator weren't running. That can't be normal.

I'm going to swap the thermostat friday to see if that helps. What else should I look at? Is there a sensor that tells the fans when to turn on that isn't working properly? Which fan was running when I shut the car off?

[ConElite]

The chances of the thermostat staying open are a little less that it staying closed. Since I started working on cars I have had alot of people bring in they're car for it overheating and 90% of the time its the thermostat staying closed. The way I test it is, do a little experiment. Get some Coolant and put it in a pan and then put the thermostat in and put in on the fire. That will tell you weather or not its the thermostat. If you felt air moving then one of the Fans needed to be on. My best Guess would be that its staying closed and the Water in the engine is not renewed with cold liquid so its overheating. The fan Was not doing to much if the Coolant in the Radiator is already cold but unable to get into the heads and Block. Just change it and see what happenes. Its worth the couple bucks it costs for the new one, plus its easy.