Ok first post. I need help.

I have a 1997 Chevy Blazer 146,000 miles.
4.3 LS trim.
Drain Dex cool out, flushed and replaced with green stuff.

OK I have hardly heat. I would flush the heater core but yesterday it was like -10 here in chicago.
All the spickets are frozen. My buddy told me to change the thermostat because my truck wasn't getting about 150 degrees or atleast that is what the guage on the dash read. My question is could this be a temp sensor??

Please help and thanks.
Brian

 

Thermostat probably stuck open and needs replacing. After the vehicle warms up it should be at about 195 degrees which is what the correct thermostat is rated for. If it takes a long time to heat up then the thermostat isstuck open.Also make sure you got it full of coolant because if it isvery low it will not circulate through the heater coil good.

 

Ok I replaced the t-sat and now its the same heat.The temperature is still only reading 150. I am really stuck on this.I havebeen told it might be the temp sensor. I really don't know.

 

If the heater is not getting hot ( 150 degrees) and you have the coolant at the proper level in the coolant recovery tank (plastic tank on fender) then the problem may be a worn out water pump. The fins on the pump impeller wear down with age. Have you ever replaced the pump ? If you squeeze off the top radiator hose with the engine running and warmed up, you should feel the coolant going through the hose. If you can't then I would wonder about the pump.

 

Hey thanks for helping. Yes the pump was done at GM I belive 2 years ago. If I squeeze on the radiator hose I can feel coolant moving. So what else to check for. Thanks.

 

Well brian, ( scratching my head ) you did mix the green stuff 50/50 with water, or 60/40 , right ? And filled the tank to the hot level with the engine warmed up?

 

50/50distilled water.
I can't think of anything else.
My question was could it possible be the temp sensor? I don't think so but you never know. I will have to wait until I can flush it out then. That sucks.

 

I may be wrong,[sm=smiley13.gif] but it seems that even if the sensor is reading off, the engine and heater still should get to 195. The top hose should be hot enough that you can't hold it in your hand. The sensor dosen't control how hot the water gets. It just feeds info to the PCM to ajust the fuel ratio and such.[sm=helpout.gif] I'm stumped too. BRING ON THE PROS

 

With the engine up to temp and the heater on, feel the heater core hoses. If they are not about the same temp as the upper hose(thermostat open), then there is an obstruction. Most likely the core is plugged.

What was the reason for the flush? No Heat?

My Bravada's temp guagelooks to read low at operating temp, and my heater will roast you out.

 

What was the reason to replace the coolant with Prestone Antifreeze or the "green stuff" as you call itrather than Dexcool?