what's the stock thermostat for a 97 chevy blazer?

[Tanman]

I have a 97 chevy blazer with the 4.3 V6. It doesn't matter if it's hot or cold outside, it always runs right at 140-150 degrees. If I have the AC on on a 95 degree day,it will eventually go up to 155-165 degrees. I could swear that it's suppose to have a 195 degree thermostat like most chevrolet pickups and suv's do. But like I said, it runs right at about 140-150 all the time. Should I just replace it anyway to make sure? and also, will it hurt efficiency or performance with it running that cool? I've been told if the engine isn't up to operating temp, stock that is I'm assuming, (don't know if it can be changed if a lower temp ther. is put in), that it will decrease performance and running efficiency. Anything you can tell me to help out is much appreciated! Thank you!

 

[potato]

How to you know the thermometer is not reading low?

You can buy replacement thermostats in different heat ranges. You can even test them in boiling water with a thermometer to see if they open when they should.
The problem is that it is a messy job and you need to buy the new gaskets every time you change a thermostat.

Keep in mind that those are just the temperatures it is supposed to open at.
More important is how quickly the engine comes up to temperature. If it is taking a very long time to warm up then that means the thermostat is stuck closed and coolant is circulating through the rad before the block can get hot enough.

The good thing is that thermostats and gaskets for them are cheap, they usually come off with 2 bolts and except for scraping the old gunk off and resealing it the job is not complicated.
You need to drain a bit of coolant first so you don't spill as much when you unbolt the thermostat.
Remember to top up the coolant in the block when you put the new one in. That is so it is sitting in coolant and will open when the coolant heats up enough..
Most mechanics I know just use silicone as a gasket for them now too instead of the old gasket glue.