Engine running COLD
 

I have a 2000 Blazer 4x4 with the 4.3 Vortec. The temperature gauge reads out about 130 degrees F and the water pipe coming out of the engine reads also 130-140 degrees with an external thermometer.

I replaced the Thermostat and flushed the radiator, and im still getting the same 130-140 degrees F reading on both the factory temperature gauge and the external thermometer.

All temperatures were taken after a 10 mile commute home from work. So the engine has had pleanty of time to warm up, prior to replaceing the thermostat i have been on 100 miles trips holding 130 degrees the whole way.

Does anyone have an outlook on my problem?

You need another thermostat... buy a 195 degree and dont buy the cheapo $4 one either. The good one should be around $10. Be sure to purge all the air out of the system as well.

i got the $14 one from autozone that is guaranteed to fail open if it fails, it was the most expensive one they had.

It is quite simple. The thermostat is the only item in the cooling system that regulates the temperature of the engine. So either it is not seating and closing off the flow of coolant through the "cooling" side of the system, or there is something that is bypassing the thermostat.

Yep, you need to open up the thermostat housing again and see whats going on in there. Maybe it got hot and the new one "failed" open?