Hi there.
I have a 97 chevy blazer. Starting Friday I noticed all of a sudden my temp gauge spiked up to about 210/220 and would not go down. I went on the freeway for something and it even went up to like 260 and that I don't like.

well I let it sit for the weekend when I went on vacation and this morning while coming to work it spiked way high again. Wouldn't come down. Not sure if that has anything to do with the thermostat.

 

Definitely, the temp is too high. For me, thermostat would be the 1st place to check. They can stuck.

 

Pull the thermostat and put it in a pot of boiling water. If it opens then it is good. if it is stuck or not opening all the way it is bad. Best bet would be to just replace it if you are going to go as far as taking it out. Also make sure you refill the coolant with the right kind. If it has Dexcool refill it with Dexcool.

 

 

I agree.. check to see what the sensor is telling the engine.

If you replace the thermostat, bite the bullet and get OE. $$$, but worth it.

 

I think my ACDelco one was like $14 from Amazon. Not really that much.

https://shop.advanceautoparts.com/p/...erm=thermostat

 

If it matters, this isn't the OE thermostat.

Rock Auto should have it for about the same price IIRC.

 

Is that noisy fan working? It should making a pretty good noise trying to cool your engine down.