2002 Monte Carlo will only run between 140-150 degrees but heater still blows heat?

 

So i f you have heat..
Whats the question?

 

Thermostat might have failed, when they fail they stay open.

 

Ok thanks. Was just surprised to have heat when car was running so cold.any tricks i should know when changing thermostat on 2002

 

I will say..
I'm running the stock 190 degree thermostat..
Mine runs super cold and yet mine has your typical killer chevrolet heat.

I guess I misunderstood your question?
But like said..
The thermostat maybe stuck open.

The only advise I can offer to changing out the thermostst is to careful remove the bolts in the thermostat housing.. They will/do sometimes snap in half. I would first try to tighten them ever so slightly before trying to remove them... as your removing them and it gets tight .. stop... then turn 1/8 of a turn towards tightening and then proceed to remove them. as this will help to ease the bolts all the while helping to clear the threads of any corrosion. and besure to clean all the old gasket material off before putting on the new one. Pay special attention to how the thermostat sits in the housing. So as to not put it in upside down.