I've had the check engine light come on then a few days later go back off just as mysteriously. Never could catch it on when I could get it checked. Finally today it was on so I had it checked and they guy said something the temperature was lower than something, or something like that. He then told me the thermostat was sticking open. So I bought a new one. I done a little looking around here just to be sure before I do something unecessary, and found this post: https://blazerforum.com/forum/showth...ace+thermostat

very similar to mine. Found another post on how to change it but mine is a bit more than "take 2 bolts out, change thermostat, put bolts back on". My 2001 has a throttle bracket just over one of the bolts that will have to be removed AND one of the bolts to that bracket is under the air intake! Simple job but complicated....TO THE BLAZER TO WORK ON IT ! !

Well I got the new thermostat put in, got air out, disconnected the battery to clear code, tested it and the temp is a little higher than it has always been, more"normal" now. Even puts out a bit more heat now!

The stat was bad because there was evidence of it rubbing or binding when you push it open so that definitely was my problem.

 

Always nice to get something fixed, isn't it?

I remember when I changed my tstat that is was a pain just to remove all the interference. A 10 minute job that took close to an hour as I recall.

 

Wasn't as bad as I first thought. I had to remove the air intake cover. . .


. . .so I could remove the throttle bracket covering the housing . . .


. . . so I could get to the 2 bolts that held the thermostat housing.

 

Thats the same thing mine said as far as the running to cold thing. Mine only took right at fifteen minutes to do. just took the two bolts out, slid the hose back toward the driver side fender take one out put one in, done. It is actually about the easiest tstat change I've ever done