So Ive replaced my thermostat 2 times, one was a Napa one, and the one in it now is a quality GM one I got from work, both were brand new. It was running halfway between 210(its sposed to be at 195) on the Napa one, and the GM one it runs about 160-180. Why wont it get to operating temp?

 

my truck runs around the 200s too thats how hot these motors like to run

 

what exactly are u using to check the temp of the fluid in the system? You could have a defective dash guage.. pick up and infrared heat tool, i got one at lowes, aim it at the rad and heater hoses to get temps in the system. don`t just rely on the dash guage. and these blazers, even your year i believe call for a 195 temp thermo..

 

yeah dont trust the dash gauge i just changed my temp sensor and thermo to a 195 degree and the dash guage says its running at about 150-160.

 

Ya i put in 2 195 degree thermos, and ya I used the dash gauge, and I agree they can be inaccurate, mine probly is. And my speedo is 5 mph slow.